Co-reporter:Chuhong Zhu, Xiujuan Wang, Xiaofei Shi, Feng Yang, Guowen Meng, Qizhong Xiong, Yan Ke, Hua Wang, Yilin Lu, and Nianqiang Wu
ACS Applied Materials & Interfaces November 15, 2017 Volume 9(Issue 45) pp:39618-39618
Publication Date(Web):October 23, 2017
DOI:10.1021/acsami.7b13479
Dithiocarbamate (DTC) pesticides are widely used for fruits, vegetables, and mature crops to control fungal diseases. Their residues in food could pose a threat to human health. Therefore, a surface-enhanced Raman scattering-based (SERS-based) sensor is developed to detect DTC pesticides because SERS can provide the characteristic spectrum of pesticides and avoid the use of a molecular recognition probe in the sensor. For the acquisition of high sensitivity, good anti-interference ability, and robustness of the SERS sensor, a silver nanocube–reduced graphene oxide (AgNC–rGO) sponge is devised. In the AgNC–rGO sponge, the rGO sheets form a porous scaffold that physically holds the AgNCs, which create narrow gaps between the neighboring AgNCs, leading to the formation of “hot spots” for SERS-signal amplification. When DTC pesticides coexist with aromatic pesticides in a sample matrix, the AgNC–rGO sponge can selectively detect DTC pesticides because of the preferential adsorption of DTC pesticides on the Ag surface and aromatic pesticides on the rGO surface, which can effectively eliminate the interference of the SERS signals of aromatic pesticides, and facilitate the qualitative and quantitative analysis of DTC pesticides. The AgNC–rGO sponge shows great potential as a SERS substrate for selective detection of DTC pesticides.Keywords: dithiocarbamate; reduced graphene oxide; silver nanocube; surface plasmon resonance; surface-enhanced Raman scattering;
Co-reporter:Chuhong Zhu, Xiujuan Wang, Xiaofei Shi, Feng Yang, Guowen Meng, Qizhong Xiong, Yan Ke, Hua Wang, Yilin Lu, and Nianqiang Wu
ACS Applied Materials & Interfaces November 15, 2017 Volume 9(Issue 45) pp:39618-39618
Publication Date(Web):October 23, 2017
DOI:10.1021/acsami.7b13479
Dithiocarbamate (DTC) pesticides are widely used for fruits, vegetables, and mature crops to control fungal diseases. Their residues in food could pose a threat to human health. Therefore, a surface-enhanced Raman scattering-based (SERS-based) sensor is developed to detect DTC pesticides because SERS can provide the characteristic spectrum of pesticides and avoid the use of a molecular recognition probe in the sensor. For the acquisition of high sensitivity, good anti-interference ability, and robustness of the SERS sensor, a silver nanocube–reduced graphene oxide (AgNC–rGO) sponge is devised. In the AgNC–rGO sponge, the rGO sheets form a porous scaffold that physically holds the AgNCs, which create narrow gaps between the neighboring AgNCs, leading to the formation of “hot spots” for SERS-signal amplification. When DTC pesticides coexist with aromatic pesticides in a sample matrix, the AgNC–rGO sponge can selectively detect DTC pesticides because of the preferential adsorption of DTC pesticides on the Ag surface and aromatic pesticides on the rGO surface, which can effectively eliminate the interference of the SERS signals of aromatic pesticides, and facilitate the qualitative and quantitative analysis of DTC pesticides. The AgNC–rGO sponge shows great potential as a SERS substrate for selective detection of DTC pesticides.Keywords: dithiocarbamate; reduced graphene oxide; silver nanocube; surface plasmon resonance; surface-enhanced Raman scattering;
Co-reporter:Yajun Yang;Xianyun Liu;Chengyu He;Yemin Hu;Zheng Hu;Lide Zhang
The Journal of Physical Chemistry C December 25, 2008 Volume 112(Issue 51) pp:20126-20130
Publication Date(Web):2017-2-22
DOI:10.1021/jp809359v
Highly oriented SiC porous nanowire (NW) arrays on Si substrate have been achieved via in situ carbonizing aligned Si NW arrays standing on Si substrate. The resultant SiC NW arrays inherit the diameter and length of the mother Si NW arrays. Field emission measurements show that these oriented SiC porous NW arrays are excellent field emitter with large field emission current denstity at very low electric field. The in situ conversion method reported here might be exploited to fabricate NW arrays of other materials containing silicon.
Co-reporter:Yan Ke;Zhulin Huang;Ningning Zhou
Journal of Materials Chemistry C 2017 vol. 5(Issue 6) pp:1402-1408
Publication Date(Web):2017/02/09
DOI:10.1039/C6TC04579K
For surface-enhanced Raman scattering (SERS)-based detection, it is desirable that the SERS substrates should not only have high SERS sensitivity, but also remarkable SERS-signal reproducibility and a good affinity for the target analytes. Herein, we report large-area membranes of plasmonic Ag-nanocubes (Ag-NCs) embedded in cellulose acetate (CA) microspheres (MSs) (denoted as Ag-NCs@CA-MSs), achieved by the electrospray technique, as highly sensitive and extremely homogeneous SERS substrates with good capture ability for analyte molecules in an aqueous solution. As a result, p-aminothiophenol (a probe molecule) and methyl parathion (a toxic pesticide) with concentrations down to 10−9 M and 10−7 M could be detected, respectively. Importantly, the membranes showed remarkable SERS-signal homogeneity over a large area, with a relative signal deviation down to 2.8% in a 500 × 500 μm2 area and 9.6% for the whole substrate (5 × 5 mm2). Moreover, Langmuir nonlinear fitting of the Raman intensity against the methyl parathion concentration was achieved, with a double-reciprocal plot of the Raman peak intensity versus the concentration showing a good linear relationship, making it possible for the quantitative SERS-based detection. Therefore, the Ag-NCs@CA-MS membranes showed potential for the quantitative SERS-based analysis of organic pollutants in the aqueous solution.
Co-reporter:Chuhong Zhu;Peng Zheng;Qing Huang;Zhongbo Li;Xiaoye Hu;Xiujuan Wang;Zhulin Huang;Fadi Li;Nianqiang Wu
Advanced Materials 2016 Volume 28( Issue 24) pp:4871-4876
Publication Date(Web):
DOI:10.1002/adma.201506251
Co-reporter:Jie Zuo, Guowen Meng, Chuhong Zhu, Qitao Zhou, Zhongbo Li, Yan Ke and Ningning Zhou
RSC Advances 2016 vol. 6(Issue 32) pp:26490-26494
Publication Date(Web):03 Mar 2016
DOI:10.1039/C6RA03223K
We report a cheap synthetic approach to large-area ordered Ag nanodendrite cluster arrays as effective surface-enhanced Raman scattering (SERS) substrates, on a Zn plate coated with periodical porous photoresist via galvanic replacement reaction of Zn and AgNO3 in aqueous solution. Due to the geometrical confinement of the porous photoresist template coated on the Zn plate, the well-positioned Ag nanodendrite clusters are distributed on the Zn plate in ordered arrays. It is demonstrated that citric acid is essential to the formation of the nanodendrite cluster arrays. The resultant Ag nanodendrite cluster arrays not only have high SERS-activity to rhodamine 6G with good signal reproducibility but also can identify thiram (a widely-used pesticide) even at 0.1 μM level, showing potential in SERS-based detection of pesticide remnants in the environment.
Co-reporter:Ningning Zhou, Qitao Zhou, Guowen Meng, Zhulin Huang, Yan Ke, Jing Liu, and Nianqiang Wu
ACS Sensors 2016 Volume 1(Issue 10) pp:1193
Publication Date(Web):October 11, 2016
DOI:10.1021/acssensors.6b00312
A basil-seed-based surface enhanced Raman scattering (SERS) sensor has been incorporated with a transfer pipet via a plastic chamber to create an integrated portable device, in which the transfer pipet is used for flow injection. A small amount of liquid sample is loaded to the dry basil-seed-based SERS sensor using the transfer pipet. The dry basil-seed can store the liquid sample like a sponge so that the plasmonic silver nanoparticles deposited on the basil-seed keep an intimate contact with the liquid sample containing the analyte, which enhances the sensitivity of the device. The excessive liquid sample is then ejected out of the plastic box by the transfer pipet, leaving the basil-seed-based SERS substrate exposed to air. This reduces the interference of the opaque liquid sample on the SERS signal, and avoids the tedious procedure for extraction of melamine from the milk. As a result, the pipet-basil-seed-based SERS device can be used to detect melamine in milk rapidly. This work has demonstrated a facile approach to construct a low-cost, safe, disposable, user-friendly, and field-deployable portable SERS device.Keywords: Basil-seed; melamine; pipet; sensor; surface-enhanced Raman scattering
Co-reporter:Qitao Zhou, Guowen Meng, Nianqiang Wu, Ningning Zhou, Bensong Chen, Fadi Li, Qing Huang
Sensors and Actuators B: Chemical 2016 Volume 223() pp:447-452
Publication Date(Web):February 2016
DOI:10.1016/j.snb.2015.09.115
•The framework of the basil-seeds has been loaded with Ag-NPs to form highly active 3D SERS substrate.•The natural edible basil-seed shows the advantages of low-cost, abundance, non-toxicity.•All the preconditioning steps are unnecessary during the detection of complex analyte.High-density plasmonic Ag nanoparticles (Ag-NPs) have been synthesized on a three-dimensional framework of natural basil seeds as the inexpensive substrates for surface-enhanced Raman scattering (SERS). The Ag-NPs decorated basil seeds (denoted as Ag-NPs@basil-seeds) are dipped into the analyte solution for rapid detection of methyl parathion in orange juice. Alternatively, they are incorporated into a microfluidic chip for online measurement of melamine in milk. The porous basil seeds can absorb trace melamine into the micro-cavity in the seeds, which load the melamine molecules into the gap where high-density “hot spots” appear under laser excitation. Hence the Ag-NPs@basil-seeds not only separate and pre-concentrate the trace analyte but also expose the analyte into the strong plasmonic field. This unique feature can eliminate the pre-treatment of analyte prior to SERS detection, and improve the sensitivity of the sensor.High-density plasmonic Ag nanoparticles (Ag-NPs) have been synthesized on the three-dimensional framework of natural basil-seeds as the inexpensive substrates for portable surface-enhanced Raman scattering (SERS) detection and SERS sensor.
Co-reporter:Jing Liu, Guowen Meng, Zhongbo Li, Zhulin Huang and Xiangdong Li
Nanoscale 2015 vol. 7(Issue 43) pp:18218-18224
Publication Date(Web):06 Oct 2015
DOI:10.1039/C5NR06001J
Surface-enhanced Raman scattering (SERS) is considered to be an excellent candidate for analytical detection schemes, because of its molecular specificity, rapid response and high sensitivity. Here, SERS-substrates of Ag-nanoparticle (Ag-NP) decorated Ge-nanotapers grafted on hexagonally ordered Si-micropillar (denoted as Ag-NP@Ge-nanotaper/Si-micropillar) arrays are fabricated via a combinatorial process of two-step etching to achieve hexagonal Si-micropillar arrays, chemical vapor deposition of flocky Ge-nanotapers on each Si-micropillar and decoration of Ag-NPs onto the Ge-nanotapers through galvanic displacement. With high density three-dimensional (3D) “hot spots” created from the large quantities of the neighboring Ag-NPs and large-scale uniform morphology, the hierarchical Ag-NP@Ge-nanotaper/Si-micropillar arrays exhibit strong and reproducible SERS activity. Using our hierarchical 3D SERS-substrates, both methyl parathion (a commonly used pesticide) and PCB-2 (one congener of highly toxic polychlorinated biphenyls) with concentrations down to 10−7 M and 10−5 M have been detected respectively, showing great potential in SERS-based rapid trace-level detection of toxic organic pollutants in the environment.
Co-reporter:Zhulin Huang, Xing Lei, Ye Liu, Zhiwei Wang, Xiujuan Wang, Zhaoming Wang, Qinghe Mao, and Guowen Meng
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 31) pp:17247
Publication Date(Web):July 17, 2015
DOI:10.1021/acsami.5b04202
Optical fiber-Raman devices integrated with plasmonic nanostructures have promising potentials for in situ probing remote liquid samples and biological samples. In this system, the fiber probe is required to simultaneously demonstrate stable surface enhanced Raman scattering (SERS) signals and high sensitivity toward the target species. Here we demonstrate a generic approach to integrate presynthesized plasmonic nanostructures with tapered fiber probes that are prepared by a dipping–etching method, through reversed electrostatic attraction between the silane couple agent modified silica fiber probe and the nanostructures. Using this approach, both negatively and positively charged plasmonic nanostructures with various morphologies (such as Au nanosphere, Ag nanocube, Au nanorod, Au@Ag core–shell nanorod) can be stably assembled on the tapered silica fiber probes. Attributed to the electrostatic force between the plasmonic units and the fiber surface, the nanostructures do not disperse in liquid samples easily, making the relative standard deviation of SERS signals as low as 2% in analyte solution. Importantly, the detection sensitivity of the system can be optimized by adjusting the cone angle (from 3.6° to 22°) and the morphology of nanostructures assembled on the fiber. Thus, the nanostructures-sensitized optical fiber-Raman probes show great potentials in the applications of SERS-based environmental detection of liquid samples.Keywords: detection; electrostatic attraction; plasmonic nanostructures; surface-enhanced Raman scattering; tapered fiber probe
Co-reporter:Fangming Han;Xinhua Li;Fei Zhou;Li Song;Xiaoye Hu;Xiaoguang Zhu;Bing Wu;Bingqing Wei
Science Advances 2015 Volume 1(Issue 9) pp:e1500605
Publication Date(Web):23 Oct 2015
DOI:10.1126/sciadv.1500605
Three-dimensional nanoarchitectural design of electrodes to simultaneously boost capacitance and breakdown voltage of dielectric capacitors.
Co-reporter:Meiling Wang;Qing Huang;Haibin Tang;Zhongbo Li
Science China Materials 2015 Volume 58( Issue 3) pp:198-203
Publication Date(Web):2015 March
DOI:10.1007/s40843-015-0032-7
We report a simple approach for the fabrication of cheap but effective surface-enhanced Raman scattering (SERS) active substrates consisting of natural egg shell membrane (ESM) grafted with Ag-nanoparticles (Ag-NPs) decorated carbon nanotubes (CNTs) (denoted as Ag-NPs@CNTs@ESM), via ultrasonic adsorption of CNTs on the ESM and the subsequent Ag-sputtering. As high density Ag-NPs were sputtered onto each CNT anchored on the ESM nanofiber, homogeneous nanoscaled gaps between the neighboring Ag-NPs were achieved, leading to high SERS activity with excellent SERS signal homogeneity over the whole membrane. Using the Ag-NPs@CNTs@ESM membranes as SERS-substrates, methyl parathion (one of the most hazardous insecticides), PCB-3 (one congener of polychlorinated biphenyls belonging to persistent organic pollutants) and bovine serum albumin (BSA, biomolecules) with a concentration down to 10−11 M, 10−6 M and 0.1 ppb were detected respectively, showing promising potentials in rapid trace detection of environmental pollutants and biochemicals.本文报道了一种利用具有均匀纤维网络结构的鸡蛋膜作为三维骨架, 制备碳纳米管/鸡蛋膜复合表面增强Raman散射SERS)衬底的简单廉价的方法. 首先, 借助超声吸附, 将碳纳米管组装到经过前处理的鸡蛋膜纤维的表面, 得到均匀的碳纳米管/鸡蛋膜复合膜; 后, 借助溅射方法, 将银纳米颗粒组装到碳纳米管和鸡蛋膜纤维的表面, 得到银纳米颗粒修饰的碳纳米管/鸡蛋膜复合膜. 这种方法制备的复合膜表面的碳纳米管对小分子目标分析物有很好的吸附和富集作用; 同时, 由于高密度银纳米颗粒的存在, 衬底表面有大量的SERS活性位点, 因此这种复合膜是一种有效的SERS衬底. 研究表明, 采用这种银纳米颗粒修饰的碳纳米管/鸡蛋膜复合SERS衬底, 可实现对农药甲基对硫磷、 多氯联苯以及生物分子牛血清蛋白等的快速痕量识别. 由于该衬底的制备方法简单、 原材料环保且来源广泛、 衬底的活性高, 所以该衬底在基于SERS技术对环境污染物和生物分子的快速痕量检测方面具有广泛的应用前景.
Co-reporter:Yao Gu;Meiling Wang;Qing Huang;Chuhong Zhu
Science China Materials 2015 Volume 58( Issue 7) pp:550-558
Publication Date(Web):2015 July
DOI:10.1007/s40843-015-0071-0
A recyclable fluorescence sensor for Hg2+ and Zn2+, based on rhodamine 6G (R6G) and 8-aminoquinoline (8-AQ) co-modified core/shell Fe3O4@SiO2 nanoparticles (denoted as R6G/8- AQ co-functionalized Fe3O4@SiO2 NPs), was developed. R6G derivative and 8-AQ derivative were conjugated onto the water- soluble core/shell Fe3O4@SiO2 nanoparticles (NPs) by covalent interaction. The R6G/8-AQ co-functionalized core/shell Fe3O4@SiO2 NPs showed fluorescence emission bands at 548 and 480 nm. When the R6G/8-AQ co-functionalized core/shell Fe3O4@SiO2 NPs were coordinated with Hg2+ and Zn2+, emission intensity at 548 nm increased with [Hg2+], while that at 480 nm increased with [Zn2+]. Moreover, there existed approximate linear relationships between fluorescence intensities and concentration of metal ions, in the range of 4.0×10-9–7.65×10-8 M for Hg2+ and 3.3×10-9–3.96×10-8 M for Zn2+, respectively. The lower detection limits for Hg2+ and Zn2+ were 1.0×10-9 and 3.0×10-9 M, respectively. The R6G/8-AQ co-functionalized core/shell Fe3O4@SiO2 NPs showed good selectivity to Hg2+ and Zn2+ over other common metal ions examined in neutral aqueous solutions. Moreover, the R6G/8-AQ co-functionalized core/shell Fe3O4@SiO2 NPs could be recycled from the detected samples using a magnet. This work has thus showed not only a practical sensing method for Zn2+ and Hg2+, but also a promising guide to the design of fluorimetric/colorimetric sensors for other targets.本文报道了一种荧光分子修饰的亲水性Fe3O4@SiO2核壳纳米颗粒的制备方法, 及其对Hg2+和Zn2+的荧光检测. 首先, 利用溶剂热方法, 制备了亲水性的磁性Fe3O4纳米颗粒; 然后, 利用传统的溶胶凝胶法在Fe3O4纳米颗粒的表面包覆SiO2壳层, 得到了Fe3O4@SiO2核壳纳米颗粒; 最后, 采用共价连接的方式, 将8-氨基喹啉(8-AQ)的衍生物(QIOEt)与罗丹明6G(R6G)的衍生物(R6GOEt)修饰到Fe3O4@SiO2核壳纳米颗粒的表面, 制备了R6G/8-AQ共同修饰的Fe3O4@SiO2核壳纳米颗粒. 研究表明, 该双通道荧光纳米颗粒 在中性水溶液中对Hg2+和Zn2+有很好的检测选择性和灵敏性, 对Zn2+和Hg2+的检测线性范围分别为3.3×10–9~3.96×10–8 Μ 和4.0×10–9~7.65×10–8 Μ.该荧光纳米材料的制备方法简单, 对Hg2+和Zn2+的灵敏度高、选择性好, 且可重复利用, 因此在环境检测领域有广泛的应用前景.
Co-reporter:Bensong Chen;Xiangdong Li;An-Ping Li
Science China Materials 2015 Volume 58( Issue 11) pp:877-883
Publication Date(Web):2015 November
DOI:10.1007/s40843-015-0097-x
This study demonstrated a simple method for gold (Au) catalyzed atmospheric pressure chemical vapor deposition (CVD) of tower-like germanium (Ge) nanostructures (denoted as Ge nanotowers) on silicon substrate. The Ge nanotowers have quasi- hexagonal cross-section with a diameter gradually decreasing from the bottom to the top end and sawtooth-faceted sidewalls. The Ge nanotowers are formed in a competitive growth process involving an Au-catalyzed axial growth and lateral growth, which can be controlled by the varied reagent vapor pressure in the CVD growth. The relationship between CVD growth kinetics and the complex morphologies was carefully examined for Ge nanostructures ranging from cylindrical and tapered nanowires to moniliform-shaped and sawtooth faceted hexagonal nanotowers in different deposition zones. The resultant complex Ge nanotowers not only enrich the family of Ge-based nanostructures, but also have potentials as building blocks for Ge-based functional nanodevices.本文以简单的金催化常压化学气相沉积法,在单晶硅片上合成了塔状锗纳米结构(简称锗纳米塔). 这种锗纳米塔的横截面为准六边形,从底端至顶端的尺寸逐渐减小,侧面含有锯齿状边缘.研究表明, 锗纳米塔的形成主要是由相互竞争的生长过程决定的:在化学气相沉积过程中,由反应物蒸汽压调控的金催化的轴向生长与径向生长之间的竞争.这种生长动力学与产物复杂形貌之间的关系可以通过不同沉积区域获得的圆柱状、圆锥状锗纳米线以及念珠状、六角锥状锗纳米塔得到验证.这种锗纳米塔不仅丰富了锗纳米结构家族,而且在锗基功能纳米器件中有潜在的应用前景.
Co-reporter:Haibin Tang;Zhongbo Li;Chuhong Zhu;Zhulin Huang
Nano Research 2015 Volume 8( Issue 7) pp:2261-2270
Publication Date(Web):2015 July
DOI:10.1007/s12274-015-0737-7
The surface topography of noble metal particles is a significant factor in tailoring surface-enhanced Raman scattering (SERS) properties. Here, we present a simple fabrication route to hexagonally arranged arrays of surface-roughened urchinlike Ag hemispheres (Ag-HSs) decorated with Ag nanoparticles (Ag-NPs) for highly active and reproducible SERS substrates. The urchin-like Ag-HS arrays are achieved by sputtering Ag onto the top surface of a highly ordered porous anodic aluminum oxide (AAO) template to form ordered arrays of smooth Ag-HSs and then by electrodepositing Ag-NPs onto the surface of each Ag-HS. Owing to the ordered arrangement of the Ag-HSs and the improved surface roughness, the urchin-like hierarchical Ag-HS arrays can provide sufficient and uniform “hot spots” for reproducible and highly active SERS effects. Using the urchin-like Ag-HS arrays as SERS substrates, 10−7 M dibutyl phthalate (a member of plasticizers family) and 1.5 × 10−5 M PCB-77 (one congener of polychlorinated biphenyl, a notorious class of pollutants) are identified, showing promising potential for these substrates in the rapid recognition of organic pollutants.
Co-reporter:Zhiwei Wang, Guowen Meng, Zhulin Huang, Zhongbo Li and Qitao Zhou
Nanoscale 2014 vol. 6(Issue 24) pp:15280-15285
Publication Date(Web):23 Oct 2014
DOI:10.1039/C4NR03398A
We report on the large-scale synthesis of Ag-nanoparticle (Ag-NP) decorated ZnO-mesoporous-nanosheets (NSs) grafted on a flexible carbon fiber cloth (CFC), as sensitive and reproducible surface enhanced Raman scattering (SERS) substrates with excellent flexibility. The composite SERS-substrates are achieved by a combination of atomic layer deposition of ZnO-seeds on each fiber of the CFC (denoted as ZnO-seeds@CFC), chemical bath deposition and subsequent pyrolysis for the creation of ZnO-mesoporous-NSs grafted on ZnO-seeds@CFC, and ion-sputtering of Ag-NPs on the ZnO-mesoporous-NSs. As abundant SERS “hot spots” are generated from the electromagnetic coupling of the densely distributed Ag-NPs, and the semiconducting ZnO-mesoporous-NSs also have chemical supporting enhancement and distinct molecule adsorbing abilities, the composite SERS-substrates demonstrate high SERS-sensitivity with good signal reproducibility. As a trial for potential applications, the composite SERS-substrates were used to identify pesticides and highly toxic polychlorinated biphenyls (PCBs), and low concentrations down to 10−7 M for methyl parathion and 5 × 10−6 M for PCB-77 were reached, respectively, showing promising potential for the SERS-based rapid detection of toxic organic pollutants in the environment.
Co-reporter:Yiwu Qian, Guowen Meng, Qing Huang, Chuhong Zhu, Zhulin Huang, Kexi Sun and Bin Chen
Nanoscale 2014 vol. 6(Issue 9) pp:4781-4788
Publication Date(Web):17 Feb 2014
DOI:10.1039/C3NR06483B
We report on a synthetic approach to produce self-supported flexible surface-enhanced Raman scattering (SERS) active membranes consisting of polyamide (PA) nanofibers grafted with vertical Ag-nanosheets, via a combinatorial process of electrospinning PA-nanofiber membranes, assembling Au-nanoparticles on the PA-nanofibers as seeds for subsequent growth of Ag-nanosheets, and electrodepositing Ag-nanosheets on the electrospun PA-nanofibers. As a high density of Ag-nanosheets are vertically grown around each PA-nanofiber in the three-dimensional (3D) networked PA-nanofiber membranes, homogeneous nano-scaled gaps between the neighboring Ag-nanosheets are formed, leading to a high density of 3D SERS “hot spots” within the Ag-nanosheet-grafted PA-nanofiber membranes. The Ag-nanosheet-grafted PA-nanofiber membranes demonstrate high SERS activity with excellent Raman signal reproducibility for rhodamine 6G over the whole membrane. For a SERS-based trial analysis of polychlorinated biphenyls (PCBs, a kind of global environmental hazard), the 3D SERS substrate membranes are modified with mono-6-β-cychlodextrin to effectively capture PCB molecules. As a result, not only a low concentration down to 10−6 M is reached, but also two congeners of PCBs in their mixed solution are identified, showing promising potential in SERS-based rapid detection of trace organic pollutants such as PCBs in the environment.
Co-reporter:Chao Hou, Guowen Meng, Qing Huang, Chuhong Zhu, Zhulin Huang, Bin Chen and Kexi Sun
Chemical Communications 2014 vol. 50(Issue 5) pp:569-571
Publication Date(Web):14 Oct 2013
DOI:10.1039/C3CC46878J
Large-area Au-aggregate-assembled fractal patterns with tailored sizes and densities are achieved by sputtering Au nanoparticles on hexagonally patterned bowl-shaped-dimples on Al foil and subsequent annealing. After decorating with much smaller Ag nanoparticles, the resultant substrates exhibit an active and reproducible SERS effect.
Co-reporter:Bin Chen, Guowen Meng, Qing Huang, Zhulin Huang, Qiaoling Xu, Chuhong Zhu, Yiwu Qian, and Yi Ding
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 18) pp:15667
Publication Date(Web):August 27, 2014
DOI:10.1021/am505474n
We present a simple green synthetic approach to large-scale and highly ordered arrays of vertical nanoporous Au nanorods, with an ultrathin Ag-layer in situ electrodeposited on each nanoporous Au nanorod (denoted as core@shell nanoporous Au@Ag nanorod). As both the nanopores within each nanorod and the gaps between the neighboring nanorods create three-dimensional (3D) “hot spots” homogeneously distributed throughout the whole substrate, the core@shell nanoporous Au@Ag nanorod arrays were proved to be sensitive and reproducible surface-enhanced Raman scattering (SERS) substrates. Not only universal probe molecules (rhodamine 6G, R6G) but also nonadsorbing molecules (polychlorinated biphenyls, PCBs) have been detected by using the substrates. After mono-6-thio-β-cyclodextrin (HS-β-CD) was modified to efficiently capture more PCBs molecules, the detection limit of PCBs was further reduced to 5.35 × 10–7 M. As a trial of practical application, R6G and PCBs with different molar ratios in their mixed solutions were identified, and two congeners of PCBs in their mixture could also be distinguished, showing great potentials in real-time simultaneous detection of multiple pollutants.Keywords: core@shell; green synthesis; large-scale uniform substrates; nanoporous nanorod arrays; rapid detection; surface-enhanced Raman scattering
Co-reporter:Xiaoye Hu, Guowen Meng, Qing Huang, Chuhong Zhu, Bensong Chen, Zhulin Huang, Fadi Li, and Zhaoming Wang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 11) pp:7991
Publication Date(Web):May 28, 2014
DOI:10.1021/am502793d
Nano-petri-dish array assisted glancing angle Ag-sputtering was reported to synthesize Ag-nanoparticle (Ag-NP) assembled bi-nanoring arrays as surface-enhanced Raman scattering (SERS) substrates. By manipulating the sputtering-Ag duration, the gaps between the Ag-NPs in the bi-nanorings are tunable to acquire optimal electromagnetic field enhancement, and the ordered bi-nanoring arrays ensure excellent reproducibility for Raman measurement. Such as-fabricated Ag-NPs assembled nanoring arrays exhibit excellent SERS performance, not only 1 × 10–12 M rhodamine 6G has been identified, but also polychlorinated biphenyls with a low concentration down to 1 × 10–9 M has been recognized, showing great potential in the detection of trace organic pollutants in the environment.Keywords: Ag-nanoparticle assembly; bi-nanoring array; localized surface plasmon resonance; surface-enhanced Raman scattering;
Co-reporter:Qitao Zhou, Guowen Meng, Qing Huang, Chuhong Zhu, Haibin Tang, Yiwu Qian, Bin Chen and Bensong Chen
Physical Chemistry Chemical Physics 2014 vol. 16(Issue 8) pp:3686-3692
Publication Date(Web):16 Dec 2013
DOI:10.1039/C3CP54119C
NiO-nanoflakes (NiO-NFs) grafted Ni-nanorod (Ni-NR) arrays stuck out of the porous anodic aluminum oxide (AAO) template are achieved by a combinatorial process of AAO-confined electrodeposition of Ni-NRs, selectively etching part of the AAO template to expose the Ni-NRs, wet-etching the exposed Ni-NRs in ammonia to obtain Ni(OH)2-NFs grafted onto the cone-shaped Ni-NRs, and annealing to transform Ni(OH)2-NFs in situ into NiO-NFs. By top-view sputtering, Ag-nanoparticles (Ag-NPs) are decorated on each NiO-NFs grafted Ni-NR (denoted as NiO-NFs@Ni-NR). The resultant Ag-NPs-decorated NiO-NFs@Ni-NR (denoted as Ag-NPs@NiO-NFs@Ni-NR) arrays exhibit not only strong surface-enhanced Raman scattering (SERS) activity but also reproducible SERS-signals over the whole array. It is demonstrated that the strong SERS-activity is mainly ascribed to the high density of sub-10 nm gaps (hot spots) between the neighboring Ag-NPs, the semiconducting NiO-NFs induced chemical enhancement effect, and the lightning rod effect of the cone-shaped Ni-NRs. The three-level hierarchical nanostructure arrays stuck out of the AAO template can be utilized to probe polychlorinated biphenyls (PCBs, a kind of global environmental hazard) with a concentration as low as 5 × 10−6 M, showing promising potential in SERS-based rapid detection of organic environmental pollutants.
Co-reporter:Meiling Wang, Guowen Meng and Qing Huang
RSC Advances 2014 vol. 4(Issue 16) pp:8055-8058
Publication Date(Web):14 Jan 2014
DOI:10.1039/C3RA47928E
We report that common erythrosin B can be used as a dual-mode fluorescent and colorimetric sensor for Ag+, Hg2+ and Fe3+, and further for halide ions in aqueous solution based on erythrosin B complexation with the three metal ions.
Co-reporter:Zhulin Huang;Qing Huang;Bin Chen;Fei Zhou;Xiaoye Hu
Nano Research 2014 Volume 7( Issue 8) pp:1177-1187
Publication Date(Web):2014 August
DOI:10.1007/s12274-014-0480-5
Co-reporter:Jing Liu, Guowen Meng, Xiangdong Li, and Zhulin Huang
Langmuir 2014 Volume 30(Issue 46) pp:13964-13969
Publication Date(Web):2017-2-22
DOI:10.1021/la5033338
We report on the fabrication of Ag nanoparticle (Ag NP) decorated germanium (Ge) nanocap (Ag-NPs@Ge-nanocap) arrays protruding from highly ordered porous anodic aluminum oxide (AAO) template as highly sensitive and uniform surface-enhanced Raman scattering (SERS) substrates. The hybrid SERS substrates are fabricated via a combinatorial process of AAO template-assisted growth of Ge nanotubes with each tube having a hemispherical nanocap on the AAO pore bottom, wet chemical etching of the remaining aluminum and the AAO barrier layer to expose the Ge nanocaps, and sputtering Ag NPs on the Ge nanocap arrays. Because sufficient SERS “hot spots” are created from the electromagnetic coupling among the Ag NPs on the Ge nanocap and the highly ordered Ge nanocap arrays also have semiconducting chemical supporting enhancement, the hybrid SERS substrates have high SERS sensitivity and good signal reproducibility. Using the hybrid SERS substrates, Rhodamine 6G with a concentration down to 10–11 M is identified, and one congener of highly toxic polychlorinated biphenyls with a concentration as low as 10–6 M is also recognized, showing great potential for SERS-based rapid detection of organic pollutants in the environment.
Co-reporter:Xiujuan Wang;Chuhong Zhu;Zhulin Huang;Yiwu Qian;Kexi Sun ;Xiaoguang Zhu
Advanced Functional Materials 2013 Volume 23( Issue 46) pp:5771-5777
Publication Date(Web):
DOI:10.1002/adfm.201301409
Abstract
The homogeneous attachment of metal-nanoparticles (metal-NPs) on pristine-graphene surface to construct pristine-graphene/metal-NPs hybrids is highly expected for application in many fields such as transparent electrodes and conductive composites. However, it remains a great challenge since the pristine-graphene is highly hydrophobic. Here, an environmentally friendly generic synthetic approach to large-scale pristine-graphene/metal-NPs hybrids is presented, by a combinatorial process of exfoliating expanded graphite in N-methyl pyrrolidone via sonication and centrifugation to achieve the pristine-graphene, and attaching pre-synthesized metal-NPs on the pristine-graphene in ethanol via van der Waals interactions between the metal-NPs and the pristine-graphene. Nanoparticles of different metals (such as Ag, Au, and Pd) with various morphologies (such as sphere, cube, plate, multi-angle, and spherical-particle assembling) can be homogeneously attached on the defect-free pristine-graphene with controlled packing densities. Both the pristine-graphene and the metal-NPs preserve their original intrinsic structures. The as-synthesized pristine-graphene/Ag-NPs hybrids show very high surface-enhanced Raman scattering activity due to the combined effects of large surface area of the pristine-graphene to adsorb more target molecules and the electromagnetic enhancement of the Ag-NPs. This large-scale synthesis of the pristine-graphene/metal-NPs hybrids with tunable shape and packing density of metal-NPs opens up opportunities for fundamental research and potential applications ranging from devices to transparent electrodes and conductive composites.
Co-reporter:Xiujuan Wang;Chuhong Zhu;Zhulin Huang;Yiwu Qian;Kexi Sun ;Xiaoguang Zhu
Advanced Functional Materials 2013 Volume 23( Issue 46) pp:
Publication Date(Web):
DOI:10.1002/adfm.201370244
Co-reporter:Xiangdong Li, Guowen Meng, An-Ping Li, Zhaoqin Chu, Xiaoguang Zhu and Mingguang Kong
Journal of Materials Chemistry A 2013 vol. 1(Issue 35) pp:5471-5476
Publication Date(Web):26 Jun 2013
DOI:10.1039/C3TC30921E
We present a facile approach for the controlled fabrication of well-aligned arrays of Ge nanotubes (GeNTs) with tunable sizes and hierarchical branches inside the pre-designed nanochannels of porous anodic aluminum oxide (AAO) templates. Metal salts, such as nickel nitrate, silver nitrate, cobalt nitrate and copper sulphate are pre-decorated on the inner wall of the AAO nanochannels as catalyst precursors, where they are reduced into nickel, silver, cobalt, and copper clusters, and provide nucleation sites for subsequent Ge growth. GeNTs are formed by confining the Ge growth on the inner walls of the porous AAO template in a low temperature (300–380 °C) chemical vapor deposition process. The as-grown GeNTs have open ends with tailored wall thickness (between 10 and 26 nm), diameter (between 80 and 248 nm), and geometrical configuration (e.g., linear, Y-branching, multi-branching, and various multiple-generation branching). The GeNT formation process is sensitive to the choice of the catalyst precursor. Nickel salts lead to a uniform wall thickness of GeNTs compared with copper, silver, and cobalt salts. And GeNTs grown with copper salts as catalysts are polycrystalline, while nickel, silver and cobalt salts assisted GeNTs are amorphous though they can crystallize via post-annealing at 400 °C in Ar/H2 atmosphere. These open-end hollow nanotubes with tunable sizes and hierarchical branches can serve as nanoscale containers or pipes to deliver fluids and molecular species, and are excellent building blocks for the construction of large-scale nanofluidic systems.
Co-reporter:Kexi Sun, Guowen Meng, Qing Huang, Xianglong Zhao, Chuhong Zhu, Zhulin Huang, Yiwu Qian, Xiujuan Wang and Xiaoye Hu
Journal of Materials Chemistry A 2013 vol. 1(Issue 33) pp:5015-5022
Publication Date(Web):14 Jun 2013
DOI:10.1039/C3TC30669K
Large area arrays of length-tunable alumina nanotips on the joints of hexagonally patterned conical-pores in an anodic aluminum oxide (AAO) template are achieved via a repeated process of anodizing Al foil for pore growth downwards and phosphoric acid etching for pore-widening. By top-view sputtering Ag on the alumina nanotip arrays, hexagonally patterned arrays of Ag-nanorods (Ag-NRs) on the alumina nanotips and uniformly distributed Ag-nanoparticles (Ag-NPs) on the upper rim of the inner surface of the conical-pores are obtained and they exhibit strong surface-enhanced Raman scattering (SERS) activity due to the high density of sub-10 nm gaps between the nearest neighboring Ag-NRs and between the adjacent Ag-NPs. The resultant nanostructures are tailored to attain an optimal SERS enhancement factor of ∼3.2 × 107 by tuning the Ag-sputtering duration. SERS measurements demonstrate that the as-fabricated large-scale Ag-nanostructures can serve as highly sensitive and reproducible SERS substrates. Finite element method calculation also confirms that the fabricated substrates possess excellent SERS activity. By modifying the Ag-NR arrays with mono-6-thio-β-cyclodextrin, the SERS detection limit of PCB-77 (a congener of polychlorinated biphenyls (PCBs)) reaches 10−6 M, showing potential in SERS-based rapid detection of trace PCBs, a kind of global environmental hazardous material.
Co-reporter:Wei Xu, Guowen Meng, Qing Huang, Xiaoye Hu, Zhulin Huang, Haibin Tang, Junxi Zhang
Applied Surface Science 2013 Volume 271() pp:125-130
Publication Date(Web):15 April 2013
DOI:10.1016/j.apsusc.2013.01.144
Abstract
Ag-nanowire (Ag-NW) tip arrays with high density sub-10-nm gaps have been achieved via anodic aluminum oxide (AAO) template-assistant approach, and exhibit superior surface enhanced Raman scattering (SERS) performance. The Ag-NW tip arrays were fabricated via the following procedures. Firstly, the pore walls of the AAO were thinned to the sub-10-nm scale, and then a layer of Ag thin film was deposited on the AAO via silver mirror reaction. Subsequently, a layer of gold (Au) film was coated on the Ag film via ion-beam evaporation to serve as the electrode for the electrodeposition growth of Ag-NWs. Finally, the Ag-NW tip arrays with sub-10-nm gaps were exposed from the AAO template by physical milling and a subsequent chemical etching. The SERS activity of the as-fabricated substrate is verified by measuring the probe molecules of R6G and polychlorinated biphenyls (PCBs). To further improve the detection sensitivity for PCBs, the substrate was modified with β-cyclodextrin to increase its efficiency of capturing PCBs molecules. As a result, the as-fabricated SERS substrate can be utilized to measure trace 3,3′,4,4′-tetrachlorinated biphenyls (PCB77) with a concentration as low as 1 × 10−10 M.
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, Yilin Lu, Yao Gu
Sensors and Actuators B: Chemical 2013 Volume 185() pp:47-52
Publication Date(Web):August 2013
DOI:10.1016/j.snb.2013.04.086
A prototype of fluorescence sensor, based on 1,4-dihydroxyanthraquinone (1,4-DHAQ) derivative and 9-fluorenylmethyl chloroformate (Fmoc-Cl) co-modified Fe3O4 magnetic nanoparticals (MNPs) (denoted as 1,4-DHAQ/Fmoc-Cl co-modified Fe3O4 MNPs), has been achieved via solvothermal synthesis of amine-functionalized Fe3O4 MNPs and subsequent surface co-modification of 1,4-DHAQ derivative and Fmoc-Cl onto the Fe3O4 MNPs. The 1,4-DHAQ/Fmoc-Cl co-modified Fe3O4 MNPs can be used for not only simple rapid qualitative detection of Cu2+, Cd2+, Zn2+ and Hg2+ in aqueous solution, but also quantitative analysis of the above four heavy metal ions with lower detection limits of 8 × 10−9, 1.5 × 10−8, 10−8 and 10−8 M, respectively. This is the first prototype of fluorescence sensor that has potentials in the detection of Cu2+, Cd2+, Zn2+ and Hg2+ in aqueous solutions and even in drinking water. The sensor designing idea might be extended to other multifunctional chemosensors.
Co-reporter:Dr. Chuhong Zhu; Guowen Meng; Qing Huang;Dr. Yao Zhang;Dr. Haibin Tang;Dr. Yiwu Qian;Dr. Bin Chen;Dr. Xiujuan Wang
Chemistry - A European Journal 2013 Volume 19( Issue 28) pp:9211-9217
Publication Date(Web):
DOI:10.1002/chem.201300454
Abstract
Ag nanoplates, as two-dimensional plasmonic nanostructures, have attracted intensive attention due to their strong shape-dependent optical properties and related applications. Here parallel face-exposed Ag nanoplates vertically grown on micro-hemisphere surfaces have been achieved by firstly electrodepositing the micro-hemispheres assembled by Ag nanoplates, whose planar surfaces are stuck together, on indium tin oxide substrates, and then Ostwald ripening the as-electrodeposited micro-hemispheres in water. The sizes of the nanoplates and the gaps between the neighboring nanoplates have been tailored by tuning the Ostwald-ripening duration, so that the SERS activity of the micro-hemispheres has been remarkably improved. The improved SERS activity can be well explained by our systematic finite-element simulation. Therefore, Ostwald ripening offers a route to the synthesis of Ag nanoplates, and the optimization of plasmon coupling and SERS activity of nanostructure-assembled systems.
Co-reporter:Haibin Tang;Qing Huang;Zhuo Zhang;Zhulin Huang;Chuhong Zhu
Advanced Functional Materials 2012 Volume 22( Issue 1) pp:218-224
Publication Date(Web):
DOI:10.1002/adfm.201102274
Abstract
A new, highly sensitive and uniform three-dimensional (3D) hybrid surface-enhanced Raman scattering (SERS) substrate has been achieved via simultaneously assembling small Ag nanoparticles (Ag-NPs) and large Ag spheres onto the side surface and the top ends of large-scale vertically aligned cone-shaped ZnO nanorods (ZnO-NRs), respectively. This 3D hybrid substrate manifests high SERS sensitivity to rhodamine and a detection limit as low as 10−11 M to polychlorinated biphenyl (PCB) 77—a kind of persistent organic pollutants as global environmental hazard. Three kinds of inter-Ag-NP gaps in 3D geometry create a huge number of SERS “hot spots” that mainly contribute to the high SERS sensitivity. Moreover, the supporting chemical enhancement effect of ZnO-NRs and the better enrichment effect ascribed to the large surface area of the substrate also help to achieve a lower detection limit. The arrays of cone-shaped ZnO-NRs decorated with Ag-NPs on their side surface and large Ag spheres on the top ends have potentials in SERS-based rapid detection of trace PCBs.
Co-reporter:Chuhong Zhu, Guowen Meng, Qing Huang, Zhongbo Li, Zhulin Huang, Meiling Wang and Jingpeng Yuan
Journal of Materials Chemistry A 2012 vol. 22(Issue 5) pp:2271-2278
Publication Date(Web):15 Dec 2011
DOI:10.1039/C2JM14823D
Large-scale well-separated Ag nanosheet-assembled micro-hemispheres with similar size and morphology were achieved on bare commercial ITO substrates via simple electrodeposition in a mixed aqueous solution of citric acid and AgNO3. It was found that appropriate electrodeposition current density and citric acid concentration are critical to the formation of well-separated nanosheet-assembled micro-hemispheres with similar size and morphology. The well-separated Ag nanosheet-assembled micro-hemispheres with similar size and morphology ensure the good surface-enhanced Raman scattering (SERS) signal reproducibility from different micro-hemispheres, and the sufficient sub-10 nm gaps on the nanosheet-assembled micro-hemispheres guarantee the high SERS sensitivity. By further modifying the Ag nanosheet-assembled micro-hemispheres with mono-6-thio-β-cyclodextrin (HS-β-CD), the SERS detection limit of 3,3′,4,4′-tetrachlorobiphenyl (PCB-77) can be further reduced, and two different polychlorinated biphenyl (PCB) congeners of 2-chlorobiphenyl (PCB-1) and PCB-77 in a mixed solution can be distinguished, indicating that the large-scale well-separated Ag nanosheet-assembled micro-hemispheres modified with HS-β-CD may have great potential as effective SERS substrates for rapid trace detection of PCBs.
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, and Yiwu Qian
Environmental Science & Technology 2012 Volume 46(Issue 1) pp:367-373
Publication Date(Web):November 30, 2011
DOI:10.1021/es202137c
1,4-Dihydroxyanthraquinone (1,4-DHAQ, a fluorophore) doped cellulose (CL) (denoted as 1,4-DHAQ@CL) microporous nanofiber film has been achieved via simple electrospinning and subsequent deacetylating, and used for highly sensitive and selective fluorescence detection of Cu2+ in aqueous solution. As the resultant byproduct of Cu2+-contaminated 1,4-DHAQ@CL nanofiber film showed recovered fluorescence by extra addition of Cr3+ nitrate solution, 1,4-DHAQ and Cu2+ codoped CL (denoted as (1,4-DHAQ)-Cu2+@CL)) microporous nanofiber film has been further fabricated for the detection of Cr3+ in aqueous solution. It was found that the fluorescence intensity of the 1,4-DHAQ@CL microporous nanofiber film linearly decreases with Cu2+ concentration ranging from 2.5 × 10–9 to 3.75 × 10–8 M, while that of the codoped (1,4-DHAQ)-Cu2+@CL nanofiber film linearly increases with Cr3+ concentration from 2.5 × 10–9 to 2.5 × 10–8 M, both with high selectivity over many other common heavy metal ions. The sensing mechanism for Cu2+ is ascribed to the formation of phenolate between 1,4-DHAQ and Cu2+, while that for Cr3+ is attributed to the reversing reaction from Cu2+-based phenolate to Cu2+ and Cr3+-based excited complex with recovered fluorescence. The sensitive and selective detection of Cu2+ and Cr3+ by using the 1,4-DHAQ@CL and the (1,4-DHAQ)-Cu2+@CL nanofiber films was further demonstrated in polluted lake waters, thus indicating their potential applications in environmental monitoring of Cu2+ and Cr3+ in polluted water. Additionally, both the 1,4-DHAQ@CL and (1,4-DHAQ)-Cu2+@CL microporous nanofiber films are reusable for the detection of Cu2+ and Cr3+, respectively, after simple treatment. The design concept in this work might also open a door to the design of effective fluorescence probes for other heavy metal ions.
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, Qiaoling Xu and Guodong Liu
Analytical Methods 2012 vol. 4(Issue 9) pp:2653-2656
Publication Date(Web):12 Jul 2012
DOI:10.1039/C2AY25576F
Polypyrrole nanowires (PPyNWs) anchored with 2-guanidinobenzimidazole (GBI) molecules (denoted as GBI@PPyNWs) have been achieved via porous anodic aluminum oxide (AAO) template-assisted approach, and used for sensitive and selective rapid fluorescence detection of Fe3+ based on the formation of coordination compound between GBI and Fe3+. The fluorescence intensity of the GBI@PPyNWs increases linearly with [Fe3+] ranging from 10−5 to 1.4 × 10−4 M in water solution, while in ethanol/water solution it linearly decreases with [Fe3+] ranging from 2 × 10−6 to 3.8 × 10−5 M, both with good selectivity. The GBI@PPyNWs were used to detect Fe3+ in blood serum solution successfully. Moreover, the GBI@PPyNWs are reusable. Our new conceptual design, using the assembly of two biocompatible materials of PPy and GBI, for the detection of Fe3+ in aqueous solution, has potential in biological detection and may open a door to the design of effective fluorescence probes for other metal ions.
Co-reporter:Chaolong Tang, Guowen Meng, Qing Huang, Zhulin Huang, Xinrui Zhang, Meiling Wang
Sensors and Actuators B: Chemical 2012 s 171–172() pp: 332-337
Publication Date(Web):
DOI:10.1016/j.snb.2012.04.033
Co-reporter:Dr. Zhongbo Li; Guowen Meng; Qing Huang;Dr. Chuhong Zhu;Dr. Zhuo Zhang;Dr. Xiangdong Li
Chemistry - A European Journal 2012 Volume 18( Issue 47) pp:14948-14953
Publication Date(Web):
DOI:10.1002/chem.201201690
Co-reporter:Xiangdong Li, Guowen Meng, Shengyong Qin, Qiaoling Xu, Zhaoqin Chu, Xiaoguang Zhu, Mingguang Kong, and An-Ping Li
ACS Nano 2012 Volume 6(Issue 1) pp:831
Publication Date(Web):December 23, 2011
DOI:10.1021/nn2043466
We report on the synthesis of multi-segment nanowire (NW) junctions of Au1–xGex and Ge inside the nanochannels of porous anodic aluminum oxide template. The one-dimensional heterostructures are grown with a low-temperature chemical vapor deposition process, assisted by electrodeposited Au nanowires (AuNWs). The Au-catalyzed vapor–liquid–solid growth process occurs simultaneously in multiple locations along the nanochannel, which leads to multi-segment Au1–xGex/Ge heterojunctions. The structures of the as-grown hybrid NWs, analyzed by using transmission electron microscopy and energy-dispersive X-ray spectroscopy elemental mapping, show clear compositional modulation with variable modulation period and controllable junction numbers. Remarkably, both GeNW and Au1–xGexNW segments are single crystalline with abrupt interfaces and good crystallographic coherences. The electronic and transport properties of individual NW junctions are measured by using a multi-probe scanning tunneling microscope, which confirms the semiconducting nature of Ge segments and the metallic behavior of Au1–xGex segments, respectively. The high yield of multiple segment NW junctions of a metal–semiconductor can facilitate the applications in nanoelectronics and optoelectronics that harness multiple functionalities of heterointerfaces.Keywords: chemical vapor deposition; electrodeposition; germanium; gold; multiple segment hybrid nanowires
Co-reporter:Xiangdong Li, Guowen Meng, Qiaoling Xu, Mingguang Kong, Xiaoguang Zhu, Zhaoqin Chu, and An-Ping Li
Nano Letters 2011 Volume 11(Issue 4) pp:1704-1709
Publication Date(Web):March 18, 2011
DOI:10.1021/nl200229p
We report on the controlled growth of germanium (Ge) nanostructures in the form of both nanowire (NW) and nanotube (NT) with ultrahigh aspect ratios and variable diameters. The nanostructures are grown inside a porous anodic aluminum oxide (AAO) template by low-temperature chemical vapor deposition (CVD) assisted by an electrodeposited metal nanorod catalyst. Depending on the choice of catalytic metals (Au, Ni, Cu, Co) and germane (GeH4) concentration during CVD, either Ge NWs or NTs can be synthesized at low growth temperatures (310−370 °C). Furthermore, Ge NWs and NTs with two or more branches can be grown from the same stem while using AAO with branched channels as templates. Transmission electron microscopy studies show that NWs are single crystalline and that branches grow epitaxially from the stem of NWs with a crystalline direction independent of diameter. As-grown NTs are amorphous but can crystallize via postannealing at 400 °C in Ar/H2 atmosphere, with a wall thickness controllable between 6 and 18 nm in the CVD process. The yield and quality of the NTs are critically dependent on the choice of the catalyst, where Ni appears the best choice for Ge NT growth among Ni, Cu, Co, and Au. The synthesis of structurally uniform and morphologically versatile Ge nanostructures may open up new opportunities for integrated Ge-nanostructure-based nanocircuits, nanodevices, and nanosystems.
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, Qiaoling Xu, Zhaoqin Chu and Chuhong Zhu
Chemical Communications 2011 vol. 47(Issue 13) pp:3808-3810
Publication Date(Web):14 Feb 2011
DOI:10.1039/C0CC05371F
A highly sensitive and selective fluorescence ratiometric sensor membrane for 2,3,3′-trichlorobiphenyl has been achieved, via depositing polypyrrole nanotubes (PPyNTs, the fluorescence indicator) in nano-porous anodic aluminium oxide (NPAAO) template and subsequently immobilizing fluorescein isothiocyanate (as an internal reference) onto the inner walls of the PPyNTs embedded in the NPAAO.
Co-reporter:Chuhong Zhu, Guowen Meng, Qing Huang, Zhuo Zhang, Qiaoling Xu, Guangqiang Liu, Zhulin Huang and Zhaoqin Chu
Chemical Communications 2011 vol. 47(Issue 9) pp:2709-2711
Publication Date(Web):23 Dec 2010
DOI:10.1039/C0CC04482B
Large-scale Ag nanosheet-assembled micro-hemispheres, with sufficient hot spots on their surfaces, have been achieved on an indium tin oxide substrate viaelectrodeposition. Surface-enhanced Raman scattering (SERS) measurements demonstrate that the Ag nanosheet-assembled micro-hemispheres can serve as sensitive and reproducible SERS substrates.
Co-reporter:Xinrui Zhang, Guowen Meng, Qing Huang, Junfeng Wang, Meiling Wang, Mingtao Li and Chaolong Tang
Analyst 2011 vol. 136(Issue 23) pp:4912-4915
Publication Date(Web):14 Oct 2011
DOI:10.1039/C1AN15260B
A potential ultra-sensitive detection approach for hexachlorobenzene (HCB), based on the measurement of the intrinsic fluorescence of well-separated HCB molecules in ethanol, has been proposed. Owing to the strong intermolecular π–π stacking interaction of the planar aromatic rings, self-aggregated HCB shows almost no fluorescence. However, the intrinsic emission of HCB can readily be detected in ethanol due to the enhanced emission from the disaggregated HCB, which is related to the hydrogen bond formation between ethanol and HCB. By simply measuring the HCB intrinsic fluorescence, a HCB concentration a little bit higher than 10−14 M (∼0.001 ppt) in ethanol can be detected; moreover, the fluorescence intensity of the HCB increases linearly with the HCB concentration ranging from 10−10 to 10−7 M. The approach might provide a simple, fast and efficient method for HCB quantification.
Co-reporter:Chuhong Zhu, Guowen Meng, Qing Huang, Zhulin Huang, and Zhaoqin Chu
Crystal Growth & Design 2011 Volume 11(Issue 3) pp:748
Publication Date(Web):January 24, 2011
DOI:10.1021/cg101266d
Arrays of Au hierarchical micro/nanotowers have been achieved on Au-coated silicon planar substrate, via electrochemical deposition in a mixed aqueous solution of PVP and HAuCl4 under appropriate electrodeposition conditions. The Au hierarchical micro/nanotower arrays have exhibited distinct surface-enhanced Raman scattering (SERS) effect due to the enhanced local electromagnetic field in the vicinity of the sharp nanotips of the towers and the gaps between the neighboring nanotowers. More importantly, the SERS effect has been further improved significantly via decorating Ag nanoparticles on the surfaces of the Au hierarchical micro/nanotowers due to the Ag nanoparticle hot spots themselves and the hot spots formed at the interfaces between the Ag nanoparticles and the Au micro/nanotowers. These Ag-nanoparticle-decorated Au hierarchical micro/nanotower arrays have shown potential applications as sensitive and robust SERS substrates in monitoring environmental pollutants, such as 3,3′,4,4′-tetrachlorobiphenyl (PCB-77).
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, Mingtao Li, Zhongbo Li and Chaolong Tang
Analyst 2011 vol. 136(Issue 2) pp:278-281
Publication Date(Web):01 Nov 2010
DOI:10.1039/C0AN00510J
A sensitive and selective fluorescent membrane for rapid detection of trace 2,2′,4,5,5′-pentachlorinated biphenyl (PCB101) has been achieved by immobilizing the fluorophore phenyl isothiocyanate (PITC) onto porous anodic aluminium oxide (AAO) membrane (denoted as PITC@AAO). The fluorescence of the PITC@AAO membrane is obviously enhanced after titrating the analyte PCB101 into the membrane, being ascribed to the halogen-bonding interaction between the fluorophore PITC and the analyte PCB101. The fluorescence intensity increases with the PCB101 concentration in the low range below 1 ppm, and there exists an approximate linear relationship between the relative fluorescence intensity and the PCB101 concentration in the low range of 1–6 ppb. Moreover, the PITC@AAO membrane shows good selectivity; for example, it is insensitive to common structural analogs (polychlorinated aromatics). The mechanisms of the fluorescence enhancement and the better sensitivity and selectivity of the PITC@AAO membrane to PCB101 than that of PITC/n-hexane solution are also discussed. This work demonstrates that trace (in ppb range) PCBs can be detected by simple fluorescence measurement.
Co-reporter:Dr. Fangming Han; Guowen Meng;Dr. Qiaoling Xu;Xiaoguang Zhu;Dr. Xianglong Zhao;Dr. Bensong Chen;Dr. Xiangdong Li;Dr. Dachi Yang;Zhaoqin Chu ;Mingguang Kong
Angewandte Chemie 2011 Volume 123( Issue 9) pp:2084-2088
Publication Date(Web):
DOI:10.1002/ange.201007151
Co-reporter:Dr. Fangming Han; Guowen Meng;Dr. Qiaoling Xu;Xiaoguang Zhu;Dr. Xianglong Zhao;Dr. Bensong Chen;Dr. Xiangdong Li;Dr. Dachi Yang;Zhaoqin Chu ;Mingguang Kong
Angewandte Chemie International Edition 2011 Volume 50( Issue 9) pp:2036-2040
Publication Date(Web):
DOI:10.1002/anie.201007151
Co-reporter:Xianglong Zhao;Qiaoling Xu;Fangming Han;Qing Huang
Advanced Materials 2010 Volume 22( Issue 24) pp:2637-2641
Publication Date(Web):
DOI:10.1002/adma.200904370
Co-reporter:Zhulin Huang;Qing Huang;Yajun Yang;Chuhong Zhu;Chaolong Tang
Advanced Materials 2010 Volume 22( Issue 37) pp:4136-4139
Publication Date(Web):
DOI:10.1002/adma.201001179
Co-reporter:Bensong Chen;Qiaoling Xu;Xianglong Zhao;Xiaoguang Zhu;Mingguang Kong
Advanced Functional Materials 2010 Volume 20( Issue 21) pp:3791-3796
Publication Date(Web):
DOI:10.1002/adfm.201001190
Abstract
Branched and multi-generation branched architectures of silicon nanotubes (SiNTs) and metal nanowires (NWs), built via filling the branched and multi-generation-branched nanochannels of anodic aluminum oxide (AAO) templates by pyrolysis of silane and electrodeposition of metals, are reported. The AAO templates with branched and multi-generation-branched nanochannels are created by sequentially reducing the applied anodizing voltage multiple times during the anodization of aluminum. The desired total generation number of branching can be controlled by the times of voltage reduction during the anodization; while each generation of branching is controlled in terms of branching number, diameter and length. The approach allows precise control over the complexity of the SiNTs and metal NWs with several levels of junctions and branching that have potentials in nanoelectronics, nanomagnetism and nanosystems.
Co-reporter:Qiaoling Xu, ;Bensong Chen;Xiangdong Li;Xiaoguang Zhu;Zhaoqin Chu ;Mingguang Kong
European Journal of Inorganic Chemistry 2010 Volume 2010( Issue 27) pp:4309-4313
Publication Date(Web):
DOI:10.1002/ejic.201000321
Abstract
A facile and economic approach has been developed for the synthesis of coaxial nanocables with AuNi alloy nanowires as inner solid cores and NiO as outer shells by infiltrating a gold-coated anodic aluminum oxide (AAO) template, with ring-shaped Al foil on its outer edge, with a mixed aqueous solution of NiCl2 and HAuCl4 to form AuNi/Ni nanocables, and subsequent immersion in an aqueous NaOH solution to oxidize the Ni sheath during template removal. The formation of the AuNi/Ni nanocables in the channels of the AAO template could be ascribed to the reduction of the Ni2+ ion complexes adhering on the AAO channel walls and the redox reactions of two galvanic cells in which the surrounding Al foil acts as the anode. The approach enables excellent control over the shell thickness and the chemical composition of the AuNi/NiO nanocable by tuning the composition of the mixed solution. The AuNi/NiO nanocables have potentials in nanodevices and nanosystems.
Co-reporter:Zhuo Zhang, Guowen Meng, Qiaoling Xu, Yemin Hu, Qiang Wu and Zheng Hu
The Journal of Physical Chemistry C 2010 Volume 114(Issue 1) pp:189-193
Publication Date(Web):November 3, 2009
DOI:10.1021/jp9087223
Large-scale arrays of aligned ZnO hexagonal nanorods with planar ends have been achieved on a bare native n-type (100) Si substrate via a simple electrochemical deposition in Zn(NH3)4(NO3)2 solution with a pure Zn sheet as the anode without using any catalysts, additives, and additional seed crystals. The ZnO hexagonal nanorods grow from the single-crystal seeds self-formed in the initial stage of the electrochemical deposition. The diameters and the lengths of the ZnO nanorods can be tailored by adjusting the electrolyte concentration and the electrodeposition duration. Field-emission measurements show that the ZnO nanorods with smaller diameters exhibit lower turn-on field and higher current density. The well-aligned ZnO hexagonal nanorods (on Si substrate) with tunable size and field emission performance may have potentials in the future of nanotechnology.
Co-reporter:Bensong Chen, Guowen Meng, Qiaoling Xu, Xiaoguang Zhu, Mingguang Kong, Zhaoqin Chu, Fangming Han, and Zhuo Zhang
ACS Nano 2010 Volume 4(Issue 12) pp:7105
Publication Date(Web):November 16, 2010
DOI:10.1021/nn102689z
Silicon, being in the same group in the periodic table as carbon, plays a key role in modern semiconductor industry. However, unlike carbon nanotube (NT), progress remains relatively slow in silicon NT (SiNT) and SiNT-based heteroarchitectures, which would be the fundamental building blocks of various nanoscale circuits, devices, and systems. Here, we report the synthesis of linear and branched crystalline SiNTs via porous anodic aluminum oxide (AAO) self-catalyzed growth and postannealing, and the connection of crystalline SiNTs and gold nanowires (AuNWs) via a combinatorial process of electrodepositing AuNWs with predesired length and location in the channels of the AAO template and subsequent AAO self-catalyzed and postannealing growth of SiNTs in the remaining empty channels adjacent to the AuNWs. Using the approach, a large variety of two-segment AuNW/SiNT and three-segment SiNT/AuNW/SiNT heteronanostructures with both linear and branched topologies have been achieved, paving the way for the rational design and fabrication of SiNT-based nanocircuits, nanodevices, and multifunctional nanosystems in the future.Keywords: gold nanowires; interconnected heterostructures; linear and branched topologies; silicon nanotubes
Co-reporter:Mingtao Li, Guowen Meng, Qing Huang, Zhijun Yin, Mingzai Wu, Zhuo Zhang and Mingguang Kong
Langmuir 2010 Volume 26(Issue 16) pp:13703-13706
Publication Date(Web):July 23, 2010
DOI:10.1021/la101391x
To detect polychlorinated biphenyls (PCBs), a prototype of a porous ZnO sensor based on the surface photovoltage (SPV) mechanism working under visible light illumination at room temperature has been presented. The SPV of the porous ZnO sensor can be remarkably reduced under visible light illumination after PCB adsorption, and the reduction of amplitude is proportional to the population of adsorbed PCB molecules. We propose that the reduction of SPV response is due to trapping of the electrons in the surface states by the adsorbed PCBs. The lower detection limits of this new prototype sensor reach at least 2.2 μmol/L for PCB29 and 1.1 μmol/L for PCB101, respectively. So, it demonstrates great potential for practical application in trace detection of PCBs.
Co-reporter:Qiaoling Xu, Guowen Meng, Xuebang Wu, Qing Wei, Mingguang Kong, Xiaoguang Zhu and Zhaoqin Chu
Chemistry of Materials 2009 Volume 21(Issue 12) pp:2397
Publication Date(Web):March 27, 2009
DOI:10.1021/cm803458b
We report a facile, economic, and generic way to mono- and multisegment metallic nanowires (MNWs) of various pure metals (e.g., Au, Pt, Pd, Cu, Ni, and Co) and their alloys with both linear and branched topologies, by merely infiltrating aqueous solutions of metal chloride salts into Au-coated native porous anodic aluminum oxide template with Al foil on its outside edge. Redox reactions of two galvanic cells where the Al foil acts as the anode are responsible for the formation of the MNWs. Redox reaction of the top galvanic cells on the surrounding Al foil leads to the formation of metal atoms on the Al foil surface, which subsequently diffuse away from the Al foil and into the nanochannels. Simultaneously, redox reaction of the bottom galvanic cell where the Au layer serves as a cathode results in the formation of metal atoms on the top surface of the bottom Au layer, followed by crystal nucleus formation and growth upward the channels to form short MNWs. With the elongation of the infiltration duration, the diffusing metal atoms coming from the top galvanic cells reach the tips of the growing MNWs, and combine with those on the MNW tips coming from the bottom galvanic cell, resulting in longer MNWs under the nanochannel geometrical confinement. The approach enables excellent control over the composition, location, length, and diameter of the individual segments and the topology of the overall NWs that are promising for many applications in nanotechnology.
Co-reporter:Dachi Yang, Guowen Meng, Chuhong Zhu and Xiaoguang Zhu
Chemical Communications 2009 (Issue 46) pp:7110-7112
Publication Date(Web):20 Oct 2009
DOI:10.1039/B917222J
Generic approaches to nano-dots and nano-rings have been developed via sputtering an Au layer on one planar surface side of porous anodic aluminum oxide template and subsequent electrodeposition.
Co-reporter:Guangbing Yue, Guowen Meng, Qiaoling Xu, Bensong Chen, Ming Fang
Materials Letters 2009 Volume 63(Issue 12) pp:998-1000
Publication Date(Web):15 May 2009
DOI:10.1016/j.matlet.2009.01.074
Cu nanowires (NWs) with controlled crystalline orientation were obtained via electrodeposition inside the nanochannels of anodic aluminum oxide templates. By adjusting electrolyte composition, the orientation of Cu NWs was manipulated between [100] and [110]. [100]- and [110]-oriented single-crystal Cu NWs were also achieved under lower electrodeposition voltages in sulfate electrolyte and citrite electrolyte, respectively. Optical absorption spectrum measurements reveal that the surface plasma resonance peak of the Cu NW arrays has an obvious blue-shift of 11 nm when the orientation of Cu NWs is turned from [100] to [110].
Co-reporter:Fangming Han, Guowen Meng, Xianglong Zhao, Qiaoling Xu, Jianxiong Liu, Bensong Chen, Xiaoguang Zhu, Mingguang Kong
Materials Letters 2009 Volume 63(Issue 26) pp:2249-2252
Publication Date(Web):31 October 2009
DOI:10.1016/j.matlet.2009.07.044
Co-reporter:Qiaoling Xu, Guowen Meng, Fangming Han, Xianglong Zhao, Mingguang Kong, Xiaoguang Zhu
Materials Letters 2009 Volume 63(Issue 16) pp:1431-1434
Publication Date(Web):30 June 2009
DOI:10.1016/j.matlet.2009.03.026
Straight and branched nanowires (NWs) of gold and polypyrrole (PPy) were synthesized inside the pre-designed nanochannels of anodic aluminum oxide (AAO) templates via electrodeposition. The morphologies, diameters and lengths of the NWs could be tailored by tuning the topologies of the nanochannels inside the AAO template and electrodeposition parameters. The present method provides a rational way to build materials that can be electrodeposited inside the nanochannels into NWs with desired architectures, which have potentials in nanoelectronics and nanosystems.
Co-reporter:Xiaoli He;Xiaoguang Zhu;Mingguang Kong
Nano Research 2009 Volume 2( Issue 4) pp:321-326
Publication Date(Web):2009 April
DOI:10.1007/s12274-009-9029-4
Vertically oriented nanowires (NWs) of single-crystalline wurtzite GaN have been fabricated on γ-LiAlO2 (100) substrate coated with a Au layer, via a chemical vapor deposition process at 1000 °C using gallium and ammonia as source materials. The GaN NWs grow along the nonpolar [10\(
\bar 1
\)0] direction with steeply tapering tips, and have triangular cross-sections with widths of 50–100 nm and lengths of up to several microns. The GaN NWs are formed by a vapor-liquid-solid growth mechanism and the tapering tips are attributed to the temperature decrease in the final stage of the synthesis process. The aligned GaN NWs show blue-yellow emission originating from defect levels, residual impurities or surface states of the GaN NWs, and have potential applications in nanotechnology.
Co-reporter:Guowen Meng ;Fangming Han Dr.;Xianglong Zhao Dr.;Bensong Chen Dr.;Dachi Yang Dr.;Jianxiong Liu ;Qiaoling Xu Dr.;Mingguang Kong;Xiaoguang Zhu;YungJoon Jung ;Yajun Yang Dr.;Zhaoqin Chu;Min Ye;Swastik Kar Dr.;Robert Vajtai Dr.;PulickelM. Ajayan
Angewandte Chemie International Edition 2009 Volume 48( Issue 39) pp:7166-7170
Publication Date(Web):
DOI:10.1002/anie.200901999
Co-reporter:Guowen Meng ;Fangming Han Dr.;Xianglong Zhao Dr.;Bensong Chen Dr.;Dachi Yang Dr.;Jianxiong Liu ;Qiaoling Xu Dr.;Mingguang Kong;Xiaoguang Zhu;YungJoon Jung ;Yajun Yang Dr.;Zhaoqin Chu;Min Ye;Swastik Kar Dr.;Robert Vajtai Dr.;PulickelM. Ajayan
Angewandte Chemie 2009 Volume 121( Issue 39) pp:7302-7306
Publication Date(Web):
DOI:10.1002/ange.200901999
Co-reporter:Yajun Yang, Guowen Meng, Xianyun Liu, Xiaoguang Zhu, Mingguang Kong, Fangming Han, Xianglong Zhao, Qiaoling Xu and Lide Zhang
Crystal Growth & Design 2008 Volume 8(Issue 6) pp:1818
Publication Date(Web):May 7, 2008
DOI:10.1021/cg800284u
Compound nanowires (NWs) of Si-related materials, such as SiC, Si 3N 4, and Zn 2SiO 4 have been synthesized in high yield via a simple thermal evaporation, chemical reaction, and deposition process using porous silicon as the Si element source. The vapor-solid growth mechanism of NWs plays a main role in the formation of the as-prepared Si-related NWs. Photoluminescence (PL) measurements reveal that SiC NWs emit an ultraviolet light at 364 nm, Si 3N 4 NWs shows a broad PL spectrum with a maximum at 495 nm, and Zn 2SiO 4 NWs reveals a green emission at about 510 nm. These Si-related NWs have potential in both composites and optoelectronic nanodevices.
Co-reporter:Dachi Yang ; Guowen Meng ; Qiaoling Xu ; Fangming Han ; Mingguang Kong ;Lide Zhang
The Journal of Physical Chemistry C 2008 Volume 112(Issue 23) pp:8614-8616
Publication Date(Web):May 14, 2008
DOI:10.1021/jp8008892
Bismuth nanotubes (BiNTs) were synthesized by electrodeposition inside the nanochannels of an anodic aluminum oxide template coated with a thin mesh-like Au layer onto one planar surface side. By tuning the Au layer thickness and current density during electrodeposition, BiNTs with a predesigned wall thickness and with a wall thickness variation along the axis were achieved. Measurements of resistance−temperature demonstrate that BiNTs show a semiconducting electronic transport behavior, and the resistance of BiNTs with thinner walls shows a larger temperature dependence than that of BiNTs with thick walls. Our approach could be used to build other materials that can be obtained via electrodeposition into nanotubes with a designed wall thickness that might have potential in future nanotechnology.
Co-reporter:Dachi Yang, Guowen Meng, Shuyuan Zhang, Yufeng Hao, Xiaohong An, Qing Wei, Min Ye and Lide Zhang
Chemical Communications 2007 (Issue 17) pp:1733-1735
Publication Date(Web):08 Feb 2007
DOI:10.1039/B614147A
Metal and semimetal nanotube–nanowire heterojunction arrays have been achieved by sequential electrochemical-deposition inside the nanochannels of anodic aluminium oxide template with a layer of Au thin enough to leave the pores open.
Co-reporter:Yajun Yang Dr. ;Xianyun Liu Dr.;Lide Zhang
Angewandte Chemie International Edition 2007 Volume 47( Issue 2) pp:365-367
Publication Date(Web):
DOI:10.1002/anie.200703698
Co-reporter:Shuhui Sun Dr. ;Gaixia Zhang Dr.;Jean-Philippe Masse Dr.;Lide Zhang
Chemistry - A European Journal 2007 Volume 13(Issue 32) pp:
Publication Date(Web):3 AUG 2007
DOI:10.1002/chem.200700448
Branched and sub-branched SnO2 hierarchical architectures in which numerous aligned nanowires grew on the surface of nanobelt substrates have been obtained by a multistep thermal vapor deposition route. Branch size and morphology can be controlled by adjusting the temperature and duration of growth. The same approach was used to grow branched ZnO–SnO2 heterojunction nanostructures. In addition, the third level of SnO2 nanostructures was obtained by repeating the vapor deposition growth process. This technique provides a general, facile, and convenient approach for preparing even more complex nanoarchitectures, and should open up new opportunities for both fundamental research and applications, such as nanobelt-based three-dimensional nanodevices.
Co-reporter:Yajun Yang Dr. ;Xianyun Liu Dr.;Lide Zhang
Angewandte Chemie 2007 Volume 120( Issue 2) pp:371-373
Publication Date(Web):
DOI:10.1002/ange.200703698
Co-reporter:X. An;G. W. Meng;Q. Wei;X. Zhang;Y. Hao;L. D. Zhang
Advanced Materials 2005 Volume 17(Issue 14) pp:
Publication Date(Web):8 JUL 2005
DOI:10.1002/adma.200500207
A simple two-step heat-treatment process is used to create SnO2/SiO2 microrings. SnO2/SiO2 nanoparticles obtained in the first step are transformed into microrings (see Figure) in the second step owing to their low melting point and a decrease in the surface energy of the system. The SnO2/SiO2 microrings show favorable UV photoluminescence and may be used as UV laser emitters.
Co-reporter:S.H Sun, G.W Meng, G.X Zhang, T Gao, B.Y Geng, L.D Zhang, J Zuo
Chemical Physics Letters 2003 Volume 376(1–2) pp:103-107
Publication Date(Web):17 July 2003
DOI:10.1016/S0009-2614(03)00965-5
The Raman spectrum of single-crystalline rutile tin dioxide (SnO2) nanobelts synthesized by thermal evaporation of tin powders was studied. Three Raman shifts (474, 632, 774 cm−1) showed the typical feature of the rutile phase of the as-synthesized SnO2 nanobelts. It was found that two infrared (IR)-active modes (313 and 690 cm−1) appeared in Raman spectrum and some peaks were broadened.
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, Qiaoling Xu, Zhaoqin Chu and Chuhong Zhu
Chemical Communications 2011 - vol. 47(Issue 13) pp:NaN3810-3810
Publication Date(Web):2011/02/14
DOI:10.1039/C0CC05371F
A highly sensitive and selective fluorescence ratiometric sensor membrane for 2,3,3′-trichlorobiphenyl has been achieved, via depositing polypyrrole nanotubes (PPyNTs, the fluorescence indicator) in nano-porous anodic aluminium oxide (NPAAO) template and subsequently immobilizing fluorescein isothiocyanate (as an internal reference) onto the inner walls of the PPyNTs embedded in the NPAAO.
Co-reporter:Chao Hou, Guowen Meng, Qing Huang, Chuhong Zhu, Zhulin Huang, Bin Chen and Kexi Sun
Chemical Communications 2014 - vol. 50(Issue 5) pp:NaN571-571
Publication Date(Web):2013/10/14
DOI:10.1039/C3CC46878J
Large-area Au-aggregate-assembled fractal patterns with tailored sizes and densities are achieved by sputtering Au nanoparticles on hexagonally patterned bowl-shaped-dimples on Al foil and subsequent annealing. After decorating with much smaller Ag nanoparticles, the resultant substrates exhibit an active and reproducible SERS effect.
Co-reporter:Dachi Yang, Guowen Meng, Shuyuan Zhang, Yufeng Hao, Xiaohong An, Qing Wei, Min Ye and Lide Zhang
Chemical Communications 2007(Issue 17) pp:NaN1735-1735
Publication Date(Web):2007/02/08
DOI:10.1039/B614147A
Metal and semimetal nanotube–nanowire heterojunction arrays have been achieved by sequential electrochemical-deposition inside the nanochannels of anodic aluminium oxide template with a layer of Au thin enough to leave the pores open.
Co-reporter:Qitao Zhou, Guowen Meng, Qing Huang, Chuhong Zhu, Haibin Tang, Yiwu Qian, Bin Chen and Bensong Chen
Physical Chemistry Chemical Physics 2014 - vol. 16(Issue 8) pp:NaN3692-3692
Publication Date(Web):2013/12/16
DOI:10.1039/C3CP54119C
NiO-nanoflakes (NiO-NFs) grafted Ni-nanorod (Ni-NR) arrays stuck out of the porous anodic aluminum oxide (AAO) template are achieved by a combinatorial process of AAO-confined electrodeposition of Ni-NRs, selectively etching part of the AAO template to expose the Ni-NRs, wet-etching the exposed Ni-NRs in ammonia to obtain Ni(OH)2-NFs grafted onto the cone-shaped Ni-NRs, and annealing to transform Ni(OH)2-NFs in situ into NiO-NFs. By top-view sputtering, Ag-nanoparticles (Ag-NPs) are decorated on each NiO-NFs grafted Ni-NR (denoted as NiO-NFs@Ni-NR). The resultant Ag-NPs-decorated NiO-NFs@Ni-NR (denoted as Ag-NPs@NiO-NFs@Ni-NR) arrays exhibit not only strong surface-enhanced Raman scattering (SERS) activity but also reproducible SERS-signals over the whole array. It is demonstrated that the strong SERS-activity is mainly ascribed to the high density of sub-10 nm gaps (hot spots) between the neighboring Ag-NPs, the semiconducting NiO-NFs induced chemical enhancement effect, and the lightning rod effect of the cone-shaped Ni-NRs. The three-level hierarchical nanostructure arrays stuck out of the AAO template can be utilized to probe polychlorinated biphenyls (PCBs, a kind of global environmental hazard) with a concentration as low as 5 × 10−6 M, showing promising potential in SERS-based rapid detection of organic environmental pollutants.
Co-reporter:Chuhong Zhu;Qing Huang;Zhongbo Li;Zhulin Huang;Meiling Wang;Jingpeng Yuan
Journal of Materials Chemistry A 2012 - vol. 22(Issue 5) pp:
Publication Date(Web):2012/01/10
DOI:10.1039/C2JM14823D
Large-scale well-separated Ag nanosheet-assembled micro-hemispheres with similar size and morphology were achieved on bare commercial ITO substrates via simple electrodeposition in a mixed aqueous solution of citric acid and AgNO3. It was found that appropriate electrodeposition current density and citric acid concentration are critical to the formation of well-separated nanosheet-assembled micro-hemispheres with similar size and morphology. The well-separated Ag nanosheet-assembled micro-hemispheres with similar size and morphology ensure the good surface-enhanced Raman scattering (SERS) signal reproducibility from different micro-hemispheres, and the sufficient sub-10 nm gaps on the nanosheet-assembled micro-hemispheres guarantee the high SERS sensitivity. By further modifying the Ag nanosheet-assembled micro-hemispheres with mono-6-thio-β-cyclodextrin (HS-β-CD), the SERS detection limit of 3,3′,4,4′-tetrachlorobiphenyl (PCB-77) can be further reduced, and two different polychlorinated biphenyl (PCB) congeners of 2-chlorobiphenyl (PCB-1) and PCB-77 in a mixed solution can be distinguished, indicating that the large-scale well-separated Ag nanosheet-assembled micro-hemispheres modified with HS-β-CD may have great potential as effective SERS substrates for rapid trace detection of PCBs.
Co-reporter:Kexi Sun, Guowen Meng, Qing Huang, Xianglong Zhao, Chuhong Zhu, Zhulin Huang, Yiwu Qian, Xiujuan Wang and Xiaoye Hu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 33) pp:NaN5022-5022
Publication Date(Web):2013/06/14
DOI:10.1039/C3TC30669K
Large area arrays of length-tunable alumina nanotips on the joints of hexagonally patterned conical-pores in an anodic aluminum oxide (AAO) template are achieved via a repeated process of anodizing Al foil for pore growth downwards and phosphoric acid etching for pore-widening. By top-view sputtering Ag on the alumina nanotip arrays, hexagonally patterned arrays of Ag-nanorods (Ag-NRs) on the alumina nanotips and uniformly distributed Ag-nanoparticles (Ag-NPs) on the upper rim of the inner surface of the conical-pores are obtained and they exhibit strong surface-enhanced Raman scattering (SERS) activity due to the high density of sub-10 nm gaps between the nearest neighboring Ag-NRs and between the adjacent Ag-NPs. The resultant nanostructures are tailored to attain an optimal SERS enhancement factor of ∼3.2 × 107 by tuning the Ag-sputtering duration. SERS measurements demonstrate that the as-fabricated large-scale Ag-nanostructures can serve as highly sensitive and reproducible SERS substrates. Finite element method calculation also confirms that the fabricated substrates possess excellent SERS activity. By modifying the Ag-NR arrays with mono-6-thio-β-cyclodextrin, the SERS detection limit of PCB-77 (a congener of polychlorinated biphenyls (PCBs)) reaches 10−6 M, showing potential in SERS-based rapid detection of trace PCBs, a kind of global environmental hazardous material.
Co-reporter:Xiangdong Li, Guowen Meng, An-Ping Li, Zhaoqin Chu, Xiaoguang Zhu and Mingguang Kong
Journal of Materials Chemistry A 2013 - vol. 1(Issue 35) pp:NaN5476-5476
Publication Date(Web):2013/06/26
DOI:10.1039/C3TC30921E
We present a facile approach for the controlled fabrication of well-aligned arrays of Ge nanotubes (GeNTs) with tunable sizes and hierarchical branches inside the pre-designed nanochannels of porous anodic aluminum oxide (AAO) templates. Metal salts, such as nickel nitrate, silver nitrate, cobalt nitrate and copper sulphate are pre-decorated on the inner wall of the AAO nanochannels as catalyst precursors, where they are reduced into nickel, silver, cobalt, and copper clusters, and provide nucleation sites for subsequent Ge growth. GeNTs are formed by confining the Ge growth on the inner walls of the porous AAO template in a low temperature (300–380 °C) chemical vapor deposition process. The as-grown GeNTs have open ends with tailored wall thickness (between 10 and 26 nm), diameter (between 80 and 248 nm), and geometrical configuration (e.g., linear, Y-branching, multi-branching, and various multiple-generation branching). The GeNT formation process is sensitive to the choice of the catalyst precursor. Nickel salts lead to a uniform wall thickness of GeNTs compared with copper, silver, and cobalt salts. And GeNTs grown with copper salts as catalysts are polycrystalline, while nickel, silver and cobalt salts assisted GeNTs are amorphous though they can crystallize via post-annealing at 400 °C in Ar/H2 atmosphere. These open-end hollow nanotubes with tunable sizes and hierarchical branches can serve as nanoscale containers or pipes to deliver fluids and molecular species, and are excellent building blocks for the construction of large-scale nanofluidic systems.
Co-reporter:Dachi Yang, Guowen Meng, Chuhong Zhu and Xiaoguang Zhu
Chemical Communications 2009(Issue 46) pp:NaN7112-7112
Publication Date(Web):2009/10/20
DOI:10.1039/B917222J
Generic approaches to nano-dots and nano-rings have been developed via sputtering an Au layer on one planar surface side of porous anodic aluminum oxide template and subsequent electrodeposition.
Co-reporter:Chuhong Zhu, Guowen Meng, Qing Huang, Zhuo Zhang, Qiaoling Xu, Guangqiang Liu, Zhulin Huang and Zhaoqin Chu
Chemical Communications 2011 - vol. 47(Issue 9) pp:NaN2711-2711
Publication Date(Web):2010/12/23
DOI:10.1039/C0CC04482B
Large-scale Ag nanosheet-assembled micro-hemispheres, with sufficient hot spots on their surfaces, have been achieved on an indium tin oxide substrate viaelectrodeposition. Surface-enhanced Raman scattering (SERS) measurements demonstrate that the Ag nanosheet-assembled micro-hemispheres can serve as sensitive and reproducible SERS substrates.
Co-reporter:Meiling Wang, Guowen Meng, Qing Huang, Qiaoling Xu and Guodong Liu
Analytical Methods (2009-Present) 2012 - vol. 4(Issue 9) pp:
Publication Date(Web):
DOI:10.1039/C2AY25576F
Co-reporter:Yan Ke, Guowen Meng, Zhulin Huang and Ningning Zhou
Journal of Materials Chemistry A 2017 - vol. 5(Issue 6) pp:NaN1408-1408
Publication Date(Web):2016/12/28
DOI:10.1039/C6TC04579K
For surface-enhanced Raman scattering (SERS)-based detection, it is desirable that the SERS substrates should not only have high SERS sensitivity, but also remarkable SERS-signal reproducibility and a good affinity for the target analytes. Herein, we report large-area membranes of plasmonic Ag-nanocubes (Ag-NCs) embedded in cellulose acetate (CA) microspheres (MSs) (denoted as Ag-NCs@CA-MSs), achieved by the electrospray technique, as highly sensitive and extremely homogeneous SERS substrates with good capture ability for analyte molecules in an aqueous solution. As a result, p-aminothiophenol (a probe molecule) and methyl parathion (a toxic pesticide) with concentrations down to 10−9 M and 10−7 M could be detected, respectively. Importantly, the membranes showed remarkable SERS-signal homogeneity over a large area, with a relative signal deviation down to 2.8% in a 500 × 500 μm2 area and 9.6% for the whole substrate (5 × 5 mm2). Moreover, Langmuir nonlinear fitting of the Raman intensity against the methyl parathion concentration was achieved, with a double-reciprocal plot of the Raman peak intensity versus the concentration showing a good linear relationship, making it possible for the quantitative SERS-based detection. Therefore, the Ag-NCs@CA-MS membranes showed potential for the quantitative SERS-based analysis of organic pollutants in the aqueous solution.
