Co-reporter:Kelong Ai;Yanlan Liu;Changping Ruan;Gaoqing (Max) Lu
Advanced Materials 2013 Volume 25( Issue 7) pp:998-1003
Publication Date(Web):
DOI:10.1002/adma.201203923
Co-reporter:Yanlan Liu;Kelong Ai;Jianhua Liu;Mo Deng;Yangyang He
Advanced Materials 2013 Volume 25( Issue 9) pp:1353-1359
Publication Date(Web):
DOI:10.1002/adma.201204683
Co-reporter:Hongmei Sun, Wenhui He, Chenghua Zong, and Lehui Lu
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 6) pp:2261
Publication Date(Web):March 2, 2013
DOI:10.1021/am400206r
The urgent need for sustainable development has forced material scientists to explore novel materials for next-generation energy storage devices through a green and facile strategy. In this context, yeast, which is a large group of single cell fungi widely distributed in nature environments, will be an ideal candidate for developing effective electrode materials with fascinating structures for high-performance supercapacitors. With this in mind, herein, we present the first example of creating three-dimensional (3D) interpenetrating macroporous carbon materials via a template-free method, using the green, renewable, and widespread yeast cells as the precursors. Remarkably, when the as-prepared materials are used as the electrode materials for supercapacitors, they exhibit outstanding performance with high specific capacitance of 330 F g–1 at a current density of 1 A g–1, and good stability, even after 1000 charge/discharge cycles. The approach developed in this work provides a new view of making full use of sustainable resources endowed by nature, opening the avenue to designing and producing robust materials with great promising applications in high-performance energy-storage devices.Keywords: carbon; macroporous materials; structure−property relationships; supercapacitors; template-free approaches;
Co-reporter:Yanlan Liu, Kelong Ai, and Lehui Lu
Accounts of Chemical Research 2012 Volume 45(Issue 10) pp:1817
Publication Date(Web):September 5, 2012
DOI:10.1021/ar300150c
X-ray computed tomography (CT) is one of the most powerful noninvasive diagnostic imaging techniques in modern medicine. Nevertheless, the iodinated molecules used as CT contrast agents in the clinic have relatively short circulation times in vivo, which significantly restrict the applications of this technique in target-specific imaging and angiography. In addition, the use of these agents can present adverse. For example, an adult patient typically receives approximately 70 mL of iodinated agent (350 mg I/mL) because of iodine’s low contrast efficacy. Rapid renal clearance of such a large dose of these agents may lead to serious adverse effects. Furthermore, some patients are hypersensitive to iodine.Therefore, biomedical researchers have invested tremendous efforts to address these issues. Over the past decade, advances in nanoscience have created new paradigms for imaging. The unique properties of nanomaterials, such as their prolonged circulating half-life, passive accumulation at the tumor sites, facile surface modification, and integration of multiple diverse functions into a single particle, make them advantageous for in vivo applications. However, research on the utilization of nanomaterials for CT imaging has lagged far behind their applications for other imaging techniques such as MRI and fluorescence imaging because of the challenges in the preparation of cost-effective nanoparticulate CT contrast agents with excellent biocompatibility, high contrast efficacy, long in vivo circulation time, and long-term colloidal stability in physiological environments.This Account reviews our recent work on the design and in vivo applications of nanoparticulate CT contrast agents. By optimizing the contrast elements in the nanoparticles according to the fundamental principles of X-ray imaging and by employing the surface engineering approaches that we and others have developed, we have synthesized several nanoparticulate CT contrast agents with excellent imaging performance. For example, a novel Yb-based nanoparticulate agent provides enhanced contrast efficacy compared to currently available CT contrast agents under normal operating conditions. To deal with special situations, we integrated both Ba and Yb with great differential in K-edge value into a single particle to yield the first example of binary contrast agents. This agent displays much higher contrast than iodinated agents at different voltages and is highly suited to diagnostic imaging of various patients. Because of their prolonged in vivo circulation time and extremely low toxicity, these agents can be used for angiography.
Co-reporter:Wenhui He
Advanced Functional Materials 2012 Volume 22( Issue 12) pp:2542-2549
Publication Date(Web):
DOI:10.1002/adfm.201102998
Abstract
Despite sustained effort over the years, the exploration of an effective strategy toward understanding the structure and properties of graphene oxide (GO) is still highly desirable. Herein, a facile route to revisit the structure of GO is demonstrated by elucidating its chemical-conversion process solely in the presence of ammonia. Such a strategy can contribute to settling some arguments in recent models of GO, and also offers a prerequisite to identify critical components that can act as ultraviolet absorbers (UVAs) in resulting dispersions of nitrogen-doped graphene sheets (NGSs). Inspired by this, for the first time, the performance of NGSs, serving as new-style UVAs, is investigated through directly assessing the effect of NGSs on the photofastness of azo dyes (Food Black). These studies reveal that, distinct from the common understanding, the as-prepared NGSs can dramatically enhance the photostability of Food Black under UV irradiation and exhibit greatly applied potential as a multifunctional UVA for new-generation inkjet inks that can simultaneously integrate the advantages of dye-based and pigment-based inks.
Co-reporter:Wei Song, Zhu Mao, Xiaojuan Liu, Yong Lu, Zhishi Li, Bing Zhao and Lehui Lu
Nanoscale 2012 vol. 4(Issue 7) pp:2333-2338
Publication Date(Web):13 Feb 2012
DOI:10.1039/C2NR12030E
The detection of metabolites is very important for the estimation of the health of human beings. Latent fingerprint contains many constituents and specific contaminants, which give much information of the individual, such as health status, drug abuse etc. For a long time, many efforts have been focused on visualizing latent fingerprints, but little attention has been paid to the detection of such substances at the same time. In this article, we have devised a versatile approach for the ultra-sensitive detection and identification of specific biomolecules deposited within fingerprints via a large-area SERS imaging technique. The antibody bound to the Raman probe modified silver nanoparticles enables the binding to specific proteins within the fingerprints to afford high-definition SERS images of the fingerprint pattern. The SERS spectra and images of Raman probes indirectly provide chemical information regarding the given proteins. By taking advantage of the high sensitivity and the capability of SERS technique to obtain abundant vibrational signatures of biomolecules, we have successfully detected minute quantities of protein present within a latent fingerprint. This technique provides a versatile and effective model to detect biomarkers within fingerprints for medical diagnostics, criminal investigation and other fields.
Co-reporter:Chenghua Zong, Xiaojuan Liu, Hongmei Sun, Guo Zhang and Lehui Lu
Journal of Materials Chemistry A 2012 vol. 22(Issue 35) pp:18418-18425
Publication Date(Web):20 Jul 2012
DOI:10.1039/C2JM32802J
A new type of nanoscale coordination particles (NCPs) are successfully synthesized on a large scale through a coordination-induced self-assembling process. The as-prepared NCPs exhibit fascinating fluorescence properties including large stokes shifts, strong photoluminescence (PL) intensity, high photochemical stability, as well as tunable emission spectra. Excitingly, this new type of NCPs enable rapid, sensitive and modification-free detection of H2S as its fluorescence can be selectively quenched in the presence of H2S. With this NCPs-based detection system, the lowest concentration to quantify H2S can be down to 2 ppm, which is five times lower than the permissible exposure limit value set by the US National Institute for Occupational Safety and Health (NIOSH). Importantly, NCPs can serve as ‘inks’ for writeable detection of H2S. The ability to directly write the H2S-sensitive NCPs under ambient conditions is really convenient and offers promising perspectives for real-time monitoring H2S.
Co-reporter:Xiaojuan Liu, Chenghua Zong, Kelong Ai, Wenhui He, and Lehui Lu
ACS Applied Materials & Interfaces 2012 Volume 4(Issue 12) pp:6599
Publication Date(Web):November 21, 2012
DOI:10.1021/am302376q
Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical tool. However, its applications for in situ detection of target molecules presented on diverse material surfaces have been hindered by difficulties in rapid fabricating SERS-active substrates on the surfaces of these materials through a simple, low-cost, and portable approach. Here, we demonstrate our attempt to address this issue by developing a facile and versatile method capable of in situ generating silver nanoparticle film (SNF) on the surfaces of both artificial and natural materials in a simple, cheap, practical, and disposable manner. Taking advantage of the high SERS enhancement ability of the prepared SNF, the proposed strategy can be used for in situ inspecting herbicide and pesticide residues on vegetables, as well as the abuse of antiseptic in aquaculture industry. Therefore, it opens new avenues for advancing the application prospects of SERS technique in the fields of food safety, drug security, as well as environment monitoring.Keywords: in situ synthesis; molecular sensing; natural material; silver nanostructures; surface-enhanced Raman spectroscopy;
Co-reporter:Yanlan Liu;Kelong Ai;Jianhua Liu;Qinghai Yuan;Yangyang He
Advanced Healthcare Materials 2012 Volume 1( Issue 4) pp:461-466
Publication Date(Web):
DOI:10.1002/adhm.201200028
Co-reporter:Xiaojuan Liu, Chenghua Zong and Lehui Lu
Analyst 2012 vol. 137(Issue 10) pp:2406-2414
Publication Date(Web):21 Mar 2012
DOI:10.1039/C2AN35051C
The development of a user-friendly sensing platform for the detection of Cu2+ in water is necessary as there are wide concerns due to the substantial impact of Cu2+ on human health, environmental monitoring, and so on. Motivated by this, we report a fluorescent silver nanoclusters (AgNCs)-based sensor for the detection of Cu2+. These water-soluble AgNCs, as a new class of fluorescent probes, were synthesized by using azobenzene modified poly(acrylic acid) (MPAA) as templates. Their fluorescence can be quenched in the presence of Cu2+, which enables the label-free detection of Cu2+ in real water samples. Furthermore, such AgNCs can be integrated onto cellulose filter paper and used as fluorescent indicators for Cu2+. The fluorescence quenching can be observed by the naked eye under UV light. It should be noted that this AgNCs-based paper assay performs successfully in barrelled drinking water and river water samples. Therefore, it opens up new avenues to the development of robust clusters-based sensing platforms.
Co-reporter:Yanlan Liu;Kelong Ai;Jianhua Liu; Qinghai Yuan;Yangyang He; Lehui Lu
Angewandte Chemie International Edition 2012 Volume 51( Issue 6) pp:1437-1442
Publication Date(Web):
DOI:10.1002/anie.201106686
Co-reporter:Yanlan Liu;Kelong Ai;Jianhua Liu; Qinghai Yuan;Yangyang He; Lehui Lu
Angewandte Chemie 2012 Volume 124( Issue 6) pp:1466-1471
Publication Date(Web):
DOI:10.1002/ange.201106686
Co-reporter:Kelong Ai;Yanlan Liu;Jianhua Liu;Qinghai Yuan;Yangyang He
Advanced Materials 2011 Volume 23( Issue 42) pp:4886-4891
Publication Date(Web):
DOI:10.1002/adma.201103289
Co-reporter:Kelong Ai, Yanlan Liu, Lehui Lu, Xiaoli Cheng and Lihua Huo
Journal of Materials Chemistry A 2011 vol. 21(Issue 10) pp:3365-3370
Publication Date(Web):29 Nov 2010
DOI:10.1039/C0JM02865G
A facile and efficient strategy is described for the fabrication of soluble reduced graphene oxide (rGO) sheets. Different from the conventional strategies, the proposed method is based on the reduction of graphene oxide by an endogenous reducing agent from a most widely used and cost-effective solvent, without adding any other toxic reducing agent. Simultaneously, this solvent can serve as an effective stabilizer, avoiding complicated and time-consuming modification procedures. The as-prepared rGO sheets not only exhibit high reduction level and conductivity, but also can be well dispersed in many solvents. Of particular significance is that rGO sheets can be produced in large quantities. These advantages endow this proposed synthetic approach great potential applications in the construction of high-performance graphene-based devices at low cost, as demonstrated in our study of NO gas sensing.
Co-reporter:Yanlan Liu, Kelong Ai and Lehui Lu
Nanoscale 2011 vol. 3(Issue 11) pp:4804-4810
Publication Date(Web):13 Oct 2011
DOI:10.1039/C1NR10752F
The widespread forgery in all kinds of paper documents and certificates has become a real threat to society. Traditional fluorescent anti-counterfeiting materials generally exhibit unicolor display and suffer greatly from substitution, thus leading to a poor anti-counterfeiting effect. In this work, unseen but significant enhanced blue down-conversion emission from oleic acid-stabilized lanthanide-doped fluoride nanocrystals is first present and the mechanism is proposed and validated. This not only endows these nanocrystals with dual-mode fluorescence, but also offers a simplified synthesis approach for dual-mode fluorescent nanocrystals involving no further complicated assembly or coating procedures, unlike the traditional methods. Furthermore, by changing the host/dopant combination or the content of dopant, these nanocrystals can exhibit simultaneously multicolor up-conversion emission under excitation at near-infrared light and unalterable blue down-conversion emission under ultraviolet light. A preliminary investigation of their anti-counterfeiting performance has been made, and the results indicate that this color tuning capability and high concealment makes these nanocrystals behave in a similar way to chameleons and can provide a strengthened and more reliable anti-counterfeiting effect.
Co-reporter:Guo Zhang, Yanlan Liu, Qinghai Yuan, Chenghua Zong, Jianhua Liu and Lehui Lu
Nanoscale 2011 vol. 3(Issue 10) pp:4365-4371
Publication Date(Web):09 Sep 2011
DOI:10.1039/C1NR10736D
In vivo upconversion luminescence (UCL) imaging, exhibiting favorable characteristics such as high photostability, no blinking, sharp emission lines, and long lifetimes, is recognized as the excellent and significant photoluminescence imaging for the future. To develop the imaging system with high visual sensitivity and tissue penetration, the functional molecules with X-ray computed tomography (CT) contrast were grafted onto upconversion nanoparticles to obtain β-NaYF4:18% Yb3+,2%Er3+@SiO2-I/PEG (UCNPs@SiO2-I/PEG) nanoprobes. These nanoprobes are water-soluble, have low cytotoxicity, and possess excellent UCL and remarkable CT contrast. Of particular note is that, besides the element iodine, rare earth elements (Y, Yb, and Er) present in the nanoprobes also show CT contrast. Moreover, no background autofluorescence signal is found in in vivoUCL images. We believe that these nanoprobes with dual modal in vivo imaging of UCL and CT can serve as a promising platform for clinical diagnosis or biomedical studies.
Co-reporter:Hongmei Sun, Qinghai Yuan, Baohua Zhang, Kelong Ai, Pengguo Zhang and Lehui Lu
Nanoscale 2011 vol. 3(Issue 5) pp:1990-1996
Publication Date(Web):08 Mar 2011
DOI:10.1039/C0NR00929F
We demonstrate a novel noncovalent method for producing GdIII-functionalized gold nanorods as multimodal contrast agents for MRI and CT imaging. The ligand is connected to the surface of the gold nanorods by a noncovalent bond making the GdIII ions directly accessible to water molecules, and resulting in a longitudinal relaxivity as high as 21.3 mM−1 s−1. In addition, compared with spherical gold nanoparticles, gold nanorods have more binding sites for GdIII ions due to their large surface-to-volume ratio. Benefiting from the advantages of the new type of carry material and the novel fabrication approach, the multimodal imaging probes exhibit a high longitudinal relaxivity r1 on the order of 1.1 × 107 mM−1 s−1 on a per-particle basis, which is 24 times higher than that of GdIII-ion-functionalized spherical gold nanoparticles. Furthermore, CT imaging shows that such nanoprobes could induce an efficient contrast enhancement when the gold concentration is at least equal to 1.31 mg ml−1. These results demonstrate that the as-prepared Gd functinalized gold nanorods could provide a new and versatile platform for the development of multimodal imaging probes.
Co-reporter:Xiaojuan Liu, Linyuan Cao, Wei Song, Kelong Ai, and Lehui Lu
ACS Applied Materials & Interfaces 2011 Volume 3(Issue 8) pp:2944
Publication Date(Web):July 5, 2011
DOI:10.1021/am200737b
Surface-enhanced Raman spectroscopy (SERS) as a powerful analytical tool has gained extensive attention. Despite of many efforts in the design of SERS substrates, it remains a grand challenge for creating a general substrate that can detect diverse target analytes. Herein, we report our attempt to address this issue by constructing a novel metal-graphene oxide nanostructured film as SERS substrate. Taking advantages of the high affinity of graphene oxide (GO) toward aromatic molecules and the SERS property of nanostructured metal, this structure exhibits great potential for diverse aromatic molecules sensing, which is demonstrated by using crystal violet (CV) with positive charge, amaranth with negative charge, and neutral phosphorus triphenyl (PPh3) as model molecules.Keywords: graphene oxide; nanostructures; self-assembly; sensors; surface-enhanced Raman spectroscopy;
Co-reporter:Chenghua Zong, Kelong Ai, Guo Zhang, Hongwei Li, and Lehui Lu
Analytical Chemistry 2011 Volume 83(Issue 8) pp:3126
Publication Date(Web):March 22, 2011
DOI:10.1021/ac2001324
An effective dual-emission fluorescent silica nanoparticle-based probe has been constructed for rapid and ultrasensitive detection of Cu2+. In this nanoprobe, a dye-doped silica core served as a reference signal, thus providing a built-in correction for environmental effects. A response dye was covalently grafted on the surface of the silica nanoparticles through a chelating reagent for Cu2+. The fluorescence of the response dye could be selectively quenched in the presence of Cu2+, accompanied by a visual orange-to-green color switch of the nanoprobe. The nanoprobe provided an effective platform for reliable detection of Cu2+ with a detection limit as low as 10 nM, which is nearly 2 × 103 times lower than the maximum level (∼20 μM) of Cu2+ in drinking water permitted by the U.S. Environmental Protection Agency (EPA). The high sensitivity was attributed to the strong chelation of Cu2+ with polyethyleneimine (PEI) and a signal amplification effect. The nanoprobe constructed by this method was very stable, enabling the rapid detection of Cu2+ in real water samples. Good linear correlations were obtained over the concentration range from 1 × 10−7 to 8 × 10−7 (R2 = 0.99) with recoveries of 103.8−99.14% and 95.5−95.14% for industrial wastewater and lake water, respectively. Additionally, the long-wavelength emission of the response dye can avoid the interference of the autofluorescence of the biosystems, which facilitated their applications in monitoring Cu2+ in cells. Furthermore, the nanoprobe showed a good reversibility; the fluorescence can be switched “off” and “on” by an addition of Cu2+ and EDTA, respectively.
Co-reporter:Linyuan Cao, Hongmei Sun, Jing Li and Lehui Lu
Analytical Methods 2011 vol. 3(Issue 7) pp:1587-1594
Publication Date(Web):02 Jun 2011
DOI:10.1039/C1AY05121K
An enhanced electrochemical sensing platform based on photoreduced graphene-polyoxometalate (PRG-POM) nanomaterials prepared by UV-assisted photoreduction method was developed for the simultaneous detection of hydroquinone (HQ), catechol (CT), and resorcinol (RS). Taking advantage of the combined benefits of graphene and POMs, these PRG-POMs nanomaterials showed fast electron-transfer kinetics for the Fe(CN)63−/4−redox system and prominent electrocatalytic activity for simultaneously determining the species mentioned above. With this sensing platform, the lowest concentration to quantify CT, HQ, and RS could be down to 40 nM, 50 nM and 90 nM, respectively. Furthermore, real samples including underground water and lake water were analyzed using the present sensing platform, and experimental results demonstrated that this electrochemical sensor exhibited excellent recoveries.
Co-reporter:Lin-Yuan CAO, Bao-Hua ZHANG, Le-Hui LU
Chinese Journal of Analytical Chemistry 2011 Volume 39(Issue 7) pp:994-997
Publication Date(Web):July 2011
DOI:10.1016/S1872-2040(10)60455-0
An effective route was developed for the fabrication of the platinum-coated silicon nanowire arrays (Pt/SiNWAs). By judiciously combining the seed-growth method and the electroless deposition technique, high-quality three-dimensional (3D) Pt nanostructure was created on the surface of large-area SiNWAs. Owing to their unique 3D structure, the as-prepared Pt/SiNWAs exhibited excellent electrocatalytic activity towards methanol oxidation in comparison with the Si wafer-supported Pt nanoparticle film and could be used as a promising nanoelectrocatalyst.
Co-reporter:Hongmei Sun;Linyuan Cao
Nano Research 2011 Volume 4( Issue 6) pp:550-562
Publication Date(Web):2011 June
DOI:10.1007/s12274-011-0111-3
A simple one step solvothermal strategy using non-toxic and cost-effective precursors has been developed to prepare magnetite/reduced graphene oxide (MRGO) nanocomposites for removal of dye pollutants. Taking advantage of the combined benefits of graphene and magnetic nanoparticles, these MRGO nanocomposites exhibit excellent removal efficiency (over 91% for rhodamine B and over 94% for malachite green) and rapid separation from aqueous solution by an external magnetic field. Interestingly, the performance of the MRGO composites is strongly dependent on both the loading of Fe3O4 and the pH value. In addition, the adsorption behavior of this new adsorbent fits well with the Freundlich isotherm and the pseudo-second-order kinetic model. In further applications, real samples—including industrial waste water and lake water—have been treated using the MRGO composites. All the results demonstrate that the MRGO composites are effective adsorbents for removal of dye pollutants and thus could provide a new platform for dye decontamination.
Co-reporter:Xiaojuan Liu, Liang Zhao, Hao Shen, Hongxing Xu, Lehui Lu
Talanta 2011 Volume 83(Issue 3) pp:1023-1029
Publication Date(Web):15 January 2011
DOI:10.1016/j.talanta.2010.11.015
Nitroexplosives, such as 2,4,6-trinitrotoluene (TNT) which is a leading example of nitroaromatic explosives, are causing wide concern. Motivated by the urgent demand for trace analysis of explosives, novel surface-enhanced Raman spectroscopy substrates based upon highly ordered Au nanoparticles have been fabricated by a simple droplet evaporation method. It is noteworthy that an ethylhexadecyldimethyl ammonium bromide bilayer surrounding each individual nanoparticle not only is responsible for these periodic gap structures, but also tends to promote the adsorption of TNT on the composite NPs, thus resulting in a considerable increase of Raman signal. These desirable features endow the resulting SERS substrates with excellent enhancement ability and allow for a label-free detection of common plastic explosive materials even with a concentration as low as 10−9 M.
Co-reporter:Yanlan Liu, Kelong Ai, Qinghai Yuan, Lehui Lu
Biomaterials 2011 32(4) pp: 1185-1192
Publication Date(Web):
DOI:10.1016/j.biomaterials.2010.10.022
Co-reporter:Yanlan Liu;Kelong Ai;Xiaoli Cheng;Lihua Huo
Advanced Functional Materials 2010 Volume 20( Issue 6) pp:951-956
Publication Date(Web):
DOI:10.1002/adfm.200902062
Abstract
A novel, gold-nanocluster-based fluorescent sensor for cyanide in aqueous solution, which is based on the cyanide etching-induced fluorescence quenching of gold nanoclusters, is reported. In addition to offering high selectivity due to the unique Elsner reaction between cyanide and the gold atoms of gold nanoclusters, this facile, environmentally friendly and cost-effective method provides high sensitivity. With this sensor, the lowest concentration to quantify cyanide ions could be down to 200 × 10−9 M, which is approximately 14 times lower than the maximum level (2.7 × 10−6 M) of cyanide in drinking water permitted by the World Health Organization (WHO). Furthermore, several real water samples spiked with cyanide, including local groundwater, tap water, pond water, and lake water, are analyzed using the sensing system, and experimental results show that this fluorescent sensor exhibits excellent recoveries (over 93%). This gold-nanocluster-based fluorescent sensor could find applications in highly sensitive and selective detection of cyanide in food, soil, water, and biological samples.
Co-reporter:Linyuan Cao, Yanlan Liu, Baohua Zhang and Lehui Lu
ACS Applied Materials & Interfaces 2010 Volume 2(Issue 8) pp:2339
Publication Date(Web):July 20, 2010
DOI:10.1021/am100372m
As a single-atom-thick carbon material with high surface area and conductivity, graphene provides an ideal platform for designing composite nanomaterials for high-performance electrocatalytic or electrochemical devices. Herein, we demonstrated a facile strategy for controllably growing high-quality Prussian blue nanocubes on the surface of reduced graphene oxide (PBNCs/rGO), which represents a new type of graphene/transition metal complex heterostructure. The merit of this method is that the composite nanomaterials could be produced directly from GO in an in situ wet-chemical reaction, where the reduction of GO and the deposition of PBNCs occurred simultaneously. The obtained composite nanomaterials were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, and electrochemical techniques. It was found that uniform PBNCs with controlled size and good dispersion were directly grown on the surface of graphene nanosheets. Moreover, we also investigated the performance of PBNCs/rGO nanocomposites as amperometric sensor toward reduction of H2O2. Such a sensor showed a rapid and highly sensitive response to H2O2 with a low detection limit (45 nM), which might find promising applications in developing a new type of enzymeless biosensor.Keywords: biosensor; electrocatalyst; graphene; hydrogen peroxide; nanocube; Prussian blue
Co-reporter:Guo Zhang, Jianghua Feng, Lehui Lu, Baohua Zhang, Linyuan Cao
Journal of Colloid and Interface Science 2010 Volume 351(Issue 1) pp:128-133
Publication Date(Web):1 November 2010
DOI:10.1016/j.jcis.2010.07.056
Multifunctional nanoprobes combining magnetic nanoparticles with organic dyes have attracted tremendous interest due to their promising applications in biomedical field. Here we demonstrate a facile and general strategy for the fabrication of robust fluorescent magnetic nanoprobes with high payloads of dye molecules and their use as multimodal nanoprobes for cell imaging. These nanoprobes not only effectively keep photochemical stability of dyes, but also provide a platform for grafting other functional or targeted moieties into silica surface via primary amines. Moreover, the nanoprobes are uniformly spherical morphology and can be dispersed well in aqueous solution, which are very desirable for biomedical applications. Importantly, this method can be extended to synthesize other bifunctional nanoprobes by using the dyes with isothiocyanate group.Graphical abstractFe3O4(FITC)@SiO2–NH2 nanoprobes with strong green fluorescence and excellent T2-relaxivity have been synthesized for cell imaging application.Research highlights► Facile and general strategy is presented for fabricating dual modal nanoprobes. ► Nanoprobes possess excellent fluorescent and magnetic properties. ► Nanoprobes can find application for magnetic resonance and fluorescent imaging.
Co-reporter:Kelong Ai ; Yanlan Liu
Journal of the American Chemical Society 2009 Volume 131(Issue 27) pp:9496-9497
Publication Date(Web):June 18, 2009
DOI:10.1021/ja9037017
The color change induced by triple hydrogen-bonding recognition between melamine and a cyanuric acid derivative grafted on the surface of gold nanoparticles can be used for reliable detection of melamine. Since such a color change can be readily seen by the naked eye, the method enables on-site and real-time detection of melamine in raw milk and infant formula even at a concentration as low as 2.5 ppb without the aid of any advanced instruments.
Co-reporter:Xinmei Zhao, Baohua Zhang, Kelong Ai, Guo Zhang, Linyuan Cao, Xiaojuan Liu, Hongmei Sun, Haishui Wang and Lehui Lu
Journal of Materials Chemistry A 2009 vol. 19(Issue 31) pp:5547-5553
Publication Date(Web):23 Jun 2009
DOI:10.1039/B902883H
Catalytic
degradation of organic dye molecules has attracted extensive attention due to their high toxicity to water resources. In this paper, we propose a novel method for the fabrication of uniform silver-coated ZnO nanowire arrays. The degradation of typical dye molecule rhodamine 6G (R6G), as an example, is investigated in the presence of the as-prepared silver-coated ZnO nanowire arrays. The experimental results show that such composite nanostructures exhibit high catalytic activity, and the reaction follows pseudo-first-order kinetics. Furthermore, these nanowire arrays are desirable SERS substrates for monitoring the catalytic degradation of dye molecules. Compared with traditional UV-visible spectroscopy, SERS technology can reflect more truly the catalytic degradation process occurring on the surface of the catalysts.
Co-reporter:Kelong Ai;Baohua Zhang
Angewandte Chemie 2009 Volume 121( Issue 2) pp:310-314
Publication Date(Web):
DOI:10.1002/ange.200804231
Co-reporter:Kelong Ai;Baohua Zhang
Angewandte Chemie International Edition 2009 Volume 48( Issue 2) pp:304-308
Publication Date(Web):
DOI:10.1002/anie.200804231
Co-reporter:Baohua Zhang;Haishui Wang;Kelong Ai;Guo Zhang;Xiaoli Cheng
Advanced Functional Materials 2008 Volume 18( Issue 16) pp:2348-2355
Publication Date(Web):
DOI:10.1002/adfm.200800153
Abstract
A new and facile method to prepare large-area silver-coated silicon nanowire arrays for surface-enhanced Raman spectroscopy (SERS)-based sensing is introduced. High-quality silicon nanowire arrays are prepared by a chemical etching method and used as a template for the generation of SERS-active silver-coated silicon nanowire arrays. The morphologies of the silicon nanowire arrays and the type of silver-plating solution are two key factors determining the magnitude of SERS signal enhancement and the sensitivity of detection; they are investigated in detail for the purpose of optimization. The optimized silver-coated silicon nanowire arrays exhibit great potential for ultrasensitive molecular sensing in terms of high SERS signal enhancement ability, good stability, and reproducibility. Their further applications in rapidly detecting molecules relating to human health and safety are discussed. A 10 s data acquisition time is capable of achieving a limit of detection of approximately 4 × 10−6M calcium dipicolinate (CaDPA), a biomarker for anthrax. This value is 1/15 the infectious dose of spores (6 × 10−5 M required), revealing that the optimized silver-coated silicon nanowire arrays as SERS-based ultrasensitive sensors are extremely suitable for detecting Bacillus anthracis spores.
Co-reporter:Xinmei Zhao, Baohua Zhang, Kelong Ai, Guo Zhang, Linyuan Cao, Xiaojuan Liu, Hongmei Sun, Haishui Wang and Lehui Lu
Journal of Materials Chemistry A 2009 - vol. 19(Issue 31) pp:NaN5553-5553
Publication Date(Web):2009/06/23
DOI:10.1039/B902883H
Catalytic
degradation of organic dye molecules has attracted extensive attention due to their high toxicity to water resources. In this paper, we propose a novel method for the fabrication of uniform silver-coated ZnO nanowire arrays. The degradation of typical dye molecule rhodamine 6G (R6G), as an example, is investigated in the presence of the as-prepared silver-coated ZnO nanowire arrays. The experimental results show that such composite nanostructures exhibit high catalytic activity, and the reaction follows pseudo-first-order kinetics. Furthermore, these nanowire arrays are desirable SERS substrates for monitoring the catalytic degradation of dye molecules. Compared with traditional UV-visible spectroscopy, SERS technology can reflect more truly the catalytic degradation process occurring on the surface of the catalysts.
Co-reporter:Linyuan Cao, Hongmei Sun, Jing Li and Lehui Lu
Analytical Methods (2009-Present) 2011 - vol. 3(Issue 7) pp:NaN1594-1594
Publication Date(Web):2011/06/02
DOI:10.1039/C1AY05121K
An enhanced electrochemical sensing platform based on photoreduced graphene-polyoxometalate (PRG-POM) nanomaterials prepared by UV-assisted photoreduction method was developed for the simultaneous detection of hydroquinone (HQ), catechol (CT), and resorcinol (RS). Taking advantage of the combined benefits of graphene and POMs, these PRG-POMs nanomaterials showed fast electron-transfer kinetics for the Fe(CN)63−/4−redox system and prominent electrocatalytic activity for simultaneously determining the species mentioned above. With this sensing platform, the lowest concentration to quantify CT, HQ, and RS could be down to 40 nM, 50 nM and 90 nM, respectively. Furthermore, real samples including underground water and lake water were analyzed using the present sensing platform, and experimental results demonstrated that this electrochemical sensor exhibited excellent recoveries.
Co-reporter:Kelong Ai, Yanlan Liu, Lehui Lu, Xiaoli Cheng and Lihua Huo
Journal of Materials Chemistry A 2011 - vol. 21(Issue 10) pp:NaN3370-3370
Publication Date(Web):2010/11/29
DOI:10.1039/C0JM02865G
A facile and efficient strategy is described for the fabrication of soluble reduced graphene oxide (rGO) sheets. Different from the conventional strategies, the proposed method is based on the reduction of graphene oxide by an endogenous reducing agent from a most widely used and cost-effective solvent, without adding any other toxic reducing agent. Simultaneously, this solvent can serve as an effective stabilizer, avoiding complicated and time-consuming modification procedures. The as-prepared rGO sheets not only exhibit high reduction level and conductivity, but also can be well dispersed in many solvents. Of particular significance is that rGO sheets can be produced in large quantities. These advantages endow this proposed synthetic approach great potential applications in the construction of high-performance graphene-based devices at low cost, as demonstrated in our study of NO gas sensing.
Co-reporter:Chenghua Zong, Xiaojuan Liu, Hongmei Sun, Guo Zhang and Lehui Lu
Journal of Materials Chemistry A 2012 - vol. 22(Issue 35) pp:NaN18425-18425
Publication Date(Web):2012/07/20
DOI:10.1039/C2JM32802J
A new type of nanoscale coordination particles (NCPs) are successfully synthesized on a large scale through a coordination-induced self-assembling process. The as-prepared NCPs exhibit fascinating fluorescence properties including large stokes shifts, strong photoluminescence (PL) intensity, high photochemical stability, as well as tunable emission spectra. Excitingly, this new type of NCPs enable rapid, sensitive and modification-free detection of H2S as its fluorescence can be selectively quenched in the presence of H2S. With this NCPs-based detection system, the lowest concentration to quantify H2S can be down to 2 ppm, which is five times lower than the permissible exposure limit value set by the US National Institute for Occupational Safety and Health (NIOSH). Importantly, NCPs can serve as ‘inks’ for writeable detection of H2S. The ability to directly write the H2S-sensitive NCPs under ambient conditions is really convenient and offers promising perspectives for real-time monitoring H2S.
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