Co-reporter:Huaping Li, Huifang Liu, Jidong Zhang, Yuxiao Cheng, Cuiling Zhang, Xinyu Fei, and Yuezhong Xian
ACS Applied Materials & Interfaces November 22, 2017 Volume 9(Issue 46) pp:40716-40716
Publication Date(Web):October 31, 2017
DOI:10.1021/acsami.7b13695
Pt nanoparticle (Pt NP)@UiO-66-NH2 composites were synthesized and encompassed the benefits of permanent porosity, high thermal and chemical stability of metal–organic frameworks (MOFs), together with the functional behavior of isolated Pt NPs. The PVP-stabilized Pt NPs with the average diameter of 2.48 nm were well dispersed and confined within the framework of UiO-66-NH2. Pt NPs possess highly peroxidase-like activities and make the composites oxidize 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2. Moreover, the specific interaction between Hg2+ and Pt NPs leads to the effective suppression of the peroxidase-like activity of Pt NP@UiO-66-NH2, which endows excellent selectivity for Hg2+ measurement over the interfering metal ions. Based on the colorimetric sensing system, Hg2+ is linearly measured over the range from 0 to 10 nM with a detection limit of 0.35 nM. Moreover, the as-obtained Pt NP@UiO-66-NH2 nanocomposites exhibit high capacity and good selectivity for Hg2+ adsorption, which is successfully applied to treat Hg2+ in water with removal efficiency over 99%. With these findings, Pt NP@UiO-66-NH2 composites can be used to develop a simple and rapid colorimetric sensing system and are utilized as nanoadsorbents for facile removal of Hg2+. This work not only expands the scientific researches on MOFs but also provides practical application in environmental, biological, and relative fields.Keywords: adsorption; colorimetric sensor; mercury(II); peroxidase mimics; Pt nanoparticle@UiO-66-NH2 composites;
Co-reporter:Wei Gu, Xueyu Pei, Yuxiao Cheng, Cuiling Zhang, Jidong Zhang, Yinghan Yan, Caiping Ding, and Yuezhong Xian
ACS Sensors April 28, 2017 Volume 2(Issue 4) pp:576-576
Publication Date(Web):April 7, 2017
DOI:10.1021/acssensors.7b00102
In this work, a novel ratiometric fluorescence sensor has been constructed for the selective and sensitive detection of Hg2+, which is based on the inner filter effect (IFE) of tetraphenylporphyrin tetrasulfonic acid (TPPS) toward black phosphorus quantum dots (BP QDs). Highly fluorescent BP QDs were successfully synthesized from bulk BP by sonication-assisted solvothermal method via a top-down route. In the presence of Hg2+, the IFE originating from spectral overlap between the excitation of BP QDs and the absorption of TPPS is inhibited and the fluorescence of BP QDs is restored. At the same time, the red fluorescence of TPPS is quenched due to its coordination with Mn2+. These phenomena result from the rapid coordination between Mn2+ and TPPS in the presence of Hg2+, which leads to the dramatic decrease of the absorption of TPPS. On the basis of these findings, we design a ratiometric fluorescence sensor for the detection of Hg2+. The as-constructed sensor reveals a good linear response to Hg2+ ranging from 1 to 60 nM with a detection limit of 0.39 nM. Furthermore, the sensing assay is applicable to detecting Hg2+ in real samples.Keywords: black phosphorus quantum dots; fluorescence; inner filter effect; mercury ion; ratiometric;
Co-reporter:Cuiling Zhang, Shiming Zhang, Yinghan Yan, Fei Xia, Anni Huang, and Yuezhong Xian
ACS Applied Materials & Interfaces April 19, 2017 Volume 9(Issue 15) pp:13415-13415
Publication Date(Web):April 4, 2017
DOI:10.1021/acsami.6b16423
A new fluorescent polyimide covalent organic framework (PI-COF) has been successfully synthesized through solvothermal route using tetra(4-aminophenyl) porphyrin and perylenetracarboxylic dianhydride, which possesses porous crystalline and excellent thermal stability (>500 °C). Furthermore, few-layered PI covalent organic nanosheets (PI-CONs) can be easily obtained from the fluorescent PI-COF through a facile liquid phase exfoliation approach, which were confirmed by atomic force microscopy and transmission electron microscopy analysis. It is interesting that the fluorescent intensity of PI-CONs is obviously enhanced relative to that of PI-COF. The PI-CONs have been successfully utilized as an efficient fluorescent probe for the highly sensitive and selective detection of 2,4,6-trinitrophenol (TNP). The mechanism might be attributed to the combination of electron transfer and inner filter effect based on DFT calculations and spectral overlap data. The system exhibits a good linear response toward TNP over the range from 0.5 to 10 μM with a detection limit of 0.25 μM.Keywords: chemosensor; fluorescence; polyimide covalent organic nanosheets; solvothermal; TNP;
Co-reporter:Caiping Ding;Xuanyu Cao;Cuiling Zhang;Tangrong He;Nan Hua
Nanoscale (2009-Present) 2017 vol. 9(Issue 37) pp:14031-14038
Publication Date(Web):2017/09/28
DOI:10.1039/C7NR04436D
In this work, a novel phenomenon was discovered that the fluorescence intensity of silver sulfide quantum dots (Ag2S QDs) could be enhanced in the presence of rare earth ions through aggregation-induced emission (AIE). Based on the strong coordination between rare earth ions and F−, a facile and label-free strategy was developed for the detection of F− in living cells. Ag2S QDs were synthesized using 3-mercaptopropionic acid as sulfur source and stabilizer in aqueous solution. The near infrared (NIR) emitting QDs exhibited excellent photostalilty, high quantum yield and low toxic. Interestingly, the fluorescence intensity of QDs was obviously enhanced upon the addition of various rare earth ions, especially in the presence of Gd3+. The AIE mechanism was proved via the TEM, zeta potential and dynamic light scattering analysis. Moreover, the coordination between rare earth ions and F− could lead to the quenching of fluorescence QDs due to the weakening the AIE. Based on these findings, we developed a highly sensitive and selective method for detection of F−. The label-free NIR fluorescence probe was successfully used for F− bioimaging in live cells.
Co-reporter:Wei Gu, Yinghan Yan, Xueyu Pei, Cuiling Zhang, Caiping Ding, Yuezhong Xian
Sensors and Actuators B: Chemical 2017 Volume 250(Volume 250) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.snb.2017.05.017
•Black phosphorus QDs were synthesized through sonication-assisted solvothermal method.•Green fluorescence QDs exhibit relative high quantum yield, good photostability and pH resistance.•A sensitive and label-free platform for fluorescent evaluation of the acetylcholinesterase activity was developed based on inner filter effect.In this work, a fast, sensitive and label-free fluorescence sensing platform for evaluating the acetylcholinesterase (AChE) activity was developed based on the inner filter effect (IFE) between black phosphorus quantum dots (BP QDs) and 2-nitro-5-thiobenzoate anion (TNB). BP QDs were successfully synthesized from bulk BP through a facile top-down route by sonication-assisted solvothermal method. The as-prepared QDs exhibit green fluorescence with a relative high quantum yield, good photostability and relative pH resistance. 5,5′-Dithiobis-(2-nitrobenzoic acid) (DTNB), as a well-known Ellman’s reagent, can react with thiol groups to form TNB. Based on the IFE between BP QDs and TNB, a sensitive and label-free sensing platform was developed for fluorescent measurement of thiols. As a proof-of-concept application, the platform was further applied in the evaluation of AChE activity by using acetylthiocholine as the substrate.
Co-reporter:Wei Gu, Yinghan Yan, Cuiling Zhang, Caiping Ding, and Yuezhong Xian
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 18) pp:11272
Publication Date(Web):April 15, 2016
DOI:10.1021/acsami.6b01166
In this work, a bottom-up strategy is developed to synthesize water-soluble molybdenum disulfide quantum dots (MoS2 QDs) through a simple, one-step hydrothermal method using ammonium tetrathiomolybdate [(NH4)2MoS4] as the precursor and hydrazine hydrate as the reducing agent. The as-synthesized MoS2 QDs are few-layered with a narrow size distribution, and the average diameter is about 2.8 nm. The resultant QDs show excitation-dependent blue fluorescence due to the polydispersity of the QDs. Moreover, the fluorescence can be quenched by hyaluronic acid (HA)-functionalized gold nanoparticles through a photoinduced electron-transfer mechanism. Hyaluronidase (HAase), an endoglucosidase, can cleave HA into proangiogenic fragments and lead to the aggregation of gold nanoparticles. As a result, the electron transfer is blocked and fluorescence is recovered. On the basis of this principle, a novel fluorescence sensor for HAase is developed with a linear range from 1 to 50 U/mL and a detection limit of 0.7 U/mL.Keywords: biosensor; fluorescence; hyaluronidase; hydrothermal method; MoS2 quantum dots
Co-reporter:Weidong Peng, Longyun Zhao, Cuiling Zhang, Yinghan Yan, Yuezhong Xian
Electrochimica Acta 2016 Volume 191() pp:669-676
Publication Date(Web):10 February 2016
DOI:10.1016/j.electacta.2016.01.129
•Rare earth metal oxide/graphene electrocatalyst with ORR activity was reported.•Electrocatalyst was synthesized by thermal treatment of Ce3+-doped GO.•Crystallization of CeO2 can be controlled through thermal treatment temperature.•CeO2/rGO nanocomposites obtained at 750 °C exhibits superior ORR activity.•Synergistic effect of CeO2 and rGO makes catalyst high performance.In this paper, a facile and simple strategy was developed for in-situ growth cerium oxide nanoparticles on reduced graphene oxide (rGO) through thermal treatment of the Ce3+-doped graphene oxide(GO) under nitrogen atmosphere. Through regulation the thermal treatment temperature, the growth of cerium oxide nanocrystals can be easily controlled in accompany with the reduction of GO. The morphology and chemical composition of the as-synthesized CeO2/rGO at different temperature are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The nanocomposites show electrocatalytic activity toward the oxygen reduction reaction (ORR) in alkaline solution. Especially, the cerium oxide nanoparticles/rGO nanocomposites treated at 750 °C possess excellent electrocatalytic ability with a dominating four-electron pathway, high tolerance of methanol and long-term operation stability due to the well exfoliation of graphene and perfect crystalline structure of cerium oxide. Compared to the commercial Pt/C catalyst, the synergistic effect of the fast electron transport of rGO and the high electrocatalytic activity of cerium oxide nanocrystals makes the nanocomposites as advanced, non-precious electrocatalysts for ORR.
Co-reporter:Longyun Zhao, Wei Gu, Cuiling Zhang, Xinhao Shi, Yuezhong Xian
Journal of Colloid and Interface Science 2016 Volume 465() pp:279-285
Publication Date(Web):1 March 2016
DOI:10.1016/j.jcis.2015.11.073
In this work, the colloid of Au nanoparticles (AuNPs)/reduced graphene oxide (rGO) was synthesized by growth AuNPs on rGO via the reduction of HAuCl4 on graphene oxide (GO) nanosheets. The nanoarchitecture of the colloid could be controllably regulated through in-situ Pb2+-enhanced gold leaching reaction, which made the colloid be a flexible surface-enhanced Raman scattering (SERS) platform for Pb2+ detection. Upon the addition of Pb2+, the Raman signal of graphene underwent significant descent due to the decrease of the amount of the “hot spots”, which was originated from Pb2+-accelerated dissolution of AuNPs on the graphene surface in the present of thiosulfate (S2O32−). Based on the change of SERS signal through in situ regulation the nanoarchitecture of the colloid, a sensitive and selective strategy for Pb2+ measurement was developed with a linear range from 5 nM to 4 μM as well as a low detection limit of 1 nM. Furthermore, the SERS-based method was applied for the determination of Pb2+ in water samples with satisfactory results.Surface-enhanced Raman scattering method for sensitive and selective monitoring of Pb2+ was realized by in situ regulation the nanoarchitecture of gold nanoparticles/reduced graphene oxide through Pb2+-enhanced gold dissolution reaction.
Co-reporter:Yinghan Yan
The Journal of Physical Chemistry C 2016 Volume 120(Issue 22) pp:12170-12177
Publication Date(Web):May 18, 2016
DOI:10.1021/acs.jpcc.6b01868
A facile and eco-friendly approach for the synthesis of water-soluble WS2 quantum dots (QDs) was developed via ultrasonication and a hydrothermal process from bulk WS2. In this strategy, the dispersity of bulk WS2 in aqueous phase was improved with the aid of a surfactant (hexadecyltrimethylammonium bromide, CTAB), which could shorten the exfoliation time and improve the exfoliation efficiency to form layered WS2 nanosheets. Through hydrothermal treatment, the nanosheets were further scissored into QDs with high quality. The QDs show excellent features with narrow size distribution, good water solubility, and stable fluorescence. We find that the fluorescence of WS2 QDs can be quenched by Fe3+ through photoinduced electron transfer, and a wide detection linear range for Fe3+ is acquired. It indicates that WS2 QD can be used as a “turn-off” probe for Fe3+. In the presence of lipoic acid (LA), the fluorescence was recovered due to the stronger interaction between LA and Fe3+ than WS2 QDs. A “turn-on” sensor for LA was developed with a linear range from 1 to 10 μM and a detection limit of 0.59 μM. The strategy might be suitable for the facile synthesis of other water-soluble transition metal dichalcogenide QDs. It is expected that the water-soluble QDs have great potential applications in biological system.
Co-reporter:Caiping Ding;Yinghan Yan;Dongshan Xiang;Cuiling Zhang
Microchimica Acta 2016 Volume 183( Issue 2) pp:625-631
Publication Date(Web):2016 February
DOI:10.1007/s00604-015-1690-6
Greigite magnetic nanoparticles (Fe3S4-MNPs) were prepared and reveal a peroxidase-like activity. Kinetic studies revealed a pseudo-enzymatic activity that is much higher than that of other magnetic nanomaterial-based enzyme mimetics. This finding was exploited to design a photometric enzymatic glucose assay based on the formation of H2O2 during enzymatic oxidation of glucose by glucose oxidase, and the formation of a blue product from an enzyme substrate that is catalytically oxidized by H2O2 in the presence of Fe3S4-MNPs. Glucose can be detected in the 2 to 100 μM concentration range, and the low detection limit is 0.16 μM. The method was applied to quantify glucose in human serum. In our perception, this enzyme mimetic has a large potential in that it may be used in other oxidase based assays, but also in ELISAs.
Co-reporter:Kai Zhao, Wei Gu, Longyun Zhao, Cuiling Zhang, Weidong Peng, Yuezhong Xian
Electrochimica Acta 2015 Volume 169() pp:142-149
Publication Date(Web):1 July 2015
DOI:10.1016/j.electacta.2015.04.044
•MoS2/Nitrogen-doped graphene (NG) composites were obtained by physically mixing method.•MoS2 sheets deposited NG could be used as effective electrocatalyst for ORR.•Enhanced electrocatalytic activity is due to the synergistic effect of MoS2 and NG.•The ORR is a four-electron process based on Koutecky-Levich equation.A simple yet effective strategy was developed to generate a non-precious oxygen electrode electrocatalyst of MoS2/nitrogen-doped graphene (NG) by physical mixing MoS2 sheets with NG. The micrometer-sized MoS2 sheets were obtained through ultrasonication exfoliation of the bulk MoS2, only showing little oxygen reduction reaction (ORR) activity. MoS2/NG hybrid was obtained by loading MoS2 sheets onto NG through ultrasonication, and the resulting nanocomposites exhibited improved electrocatalytic activity for ORR with dominant 4 electron pathway in alkaline solutions. The exposed active edges as well as the synergistic effect and reduced resistance connection jointly make the MoS2/NG composite a highly competitive ORR catalyst.A simple yet effective method was developed for generating an electrocatalyst for oxygen reduction reaction by deposited MoS2 sheets on nitrogen-doped graphene (NG). Due to the synergistic effect of MoS2 and NG, enhancement of electrocatalytic oxygen-reduction was realized.
Co-reporter:Xinhao Shi, Wei Gu, Cuiling Zhang, Longyun Zhao, Weidong Peng and Yuezhong Xian
Dalton Transactions 2015 vol. 44(Issue 10) pp:4623-4629
Publication Date(Web):28 Jan 2015
DOI:10.1039/C4DT03883E
In this work, we developed a novel, label-free, colorimetric sensor for Pb2+ detection based on the acceleration of gold leaching by graphene oxide (GO) at room temperature. Gold nanoparticles (AuNPs) can be dissolved in a thiosulfate (S2O32−) aqueous environment in the presence of oxygen; however, the leaching rate is very slow due to the high activation energy (27.99 kJ mol−1). In order to enhance the reaction rate, some accelerators should be added. In comparison with the traditional accelerators (metal ions or middle ligands), we found that GO could efficiently accelerate the gold leaching reaction. Kinetic data demonstrate that the dissolution rate of gold in the Pb2+–S2O32−–GO system is 5 times faster than that without GO at room temperature. In addition, the effects of surface modification and the nanoparticle size on the etching of AuNPs were investigated. Based on the GO-accelerated concentration-dependent colour changes of AuNPs, a colorimetric sensor for Pb2+ detection was developed with a linear range from 0.1 to 20 μM and the limit of detection (LOD) was evaluated to be 0.05 μM. This colorimetric assay is simple, low-cost, label-free, and has numerous potential applications in the field of environmental chemistry.
Co-reporter:Ningning Chen, Li Chen, Yuxiao Cheng, Kai Zhao, Xiaohong Wu, Yuezhong Xian
Talanta 2015 Volume 132() pp:155-161
Publication Date(Web):15 January 2015
DOI:10.1016/j.talanta.2014.09.008
•MIPs-G was synthesized via free radical polymerization.•MIPs-G was used as electrode material for aromatic amines detection.•Aromatic amines were detected simultaneously by DPV due to rebinding and π-π stacking.•MIPs-G based electrochemical sensor can be used for real sample analysis.A sensitive and selective electrochemical sensor based on molecular imprinting polymers grafted graphene (MIPs-G) was developed for simultaneous measurement of 4, 4-methylene diphenylamine (MDA) and aniline by differential pulse voltammetry (DPV). MIPs-G was synthesized via free radical polymerization reaction using MDA and 4-vinyl pyridine as template molecule and functional monomer respectively. The obtained nanocomposites were characterized by transmission electron microscope, scanning electron microscope, Fourier transform infrared spectrometry, Raman spectroscopy and thermal gravimetric analysis. After removal template molecules, MIPs-G was used as electrode material for aromatic amines measurements. Due to the high binding affinity towards MDA and the π-π interaction with aniline, the MIPs-G based electrochemical sensor can be used for simultaneous detection of MDA and aniline by DPV. Under the optimized condition, the oxidation potentials for MDA and aniline were observed at 0.62 and 0.72 V, respectively. Moreover, MIPs-G modified glassy carbon electrode shows linear response towards MDA and aniline simultaneously over the range of 1.0 to 15 μM. The MIPs-G based electrochemical sensor has been applied for simultaneous measurement of MDA and aniline in plastic tableware.
Co-reporter:Kai Zhao, Wei Gu, Sisi Zheng, Cuiling Zhang, Yuezhong Xian
Talanta 2015 Volume 141() pp:47-52
Publication Date(Web):15 August 2015
DOI:10.1016/j.talanta.2015.03.055
•Surface charge could affect the peroxidase-like activity of MoS2 NPs.•SDS–MoS2 NPs possess highly-efficient peroxidase-like activity.•Catalytic kinetics of SDS–MoS2 NPs show a ping–pong mechanism.•Colorimetric detection of H2O2 and glucose was realized.In this work, we find that the peroxidase-like activity of MoS2 nanoparticles (NPs) is dependent on the surface charge. Negatively charged sodium dodecyl sulfate modified MoS2 nanoparticles (SDS–MoS2 NPs) possess highly-efficient peroxidase-like activity. MoS2 NPs with intrinsic peroxidase-like activity were synthesized through a simple one-pot hydrothermal route. The peroxidase-like activities of different surfactants modified MoS2 NPs were discussed. Compared with bare MoS2 NPs and positively charged cetyltrimethyl ammonium bromide modified MoS2 NPs, SDS–MoS2 NPs have the best peroxidase-like activity. SDS–MoS2 NPs can efficiently catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2 to generate a blue product. On basis of this, we have successfully established a novel platform for colorimetric detection of H2O2, and the detection limit is 0.32 μM. Furthermore, the SDS–MoS2 NPs based platform can also be used for high sensitivity and selectivity detection of glucose with a wide linear range of 5.0–500 μM by controlling the generation of H2O2 in the presence of glucose oxidase.Sodium dodecyl sulphate modified MoS2 nanoparticles show highly-efficient peroxidase-like activity and can be used for the colorimetric detection of H2O2 and glucose.
Co-reporter:Ningning Chen;Yuxiao Cheng;Chen Li;Cuiling Zhang;Kai Zhao
Microchimica Acta 2015 Volume 182( Issue 11-12) pp:1967-1975
Publication Date(Web):2015 August
DOI:10.1007/s00604-015-1533-5
We describe an electrochemical sensor for melamine based on a glassy carbon electrode (GCE) modified with reduced graphene oxide that was decorated with gold nanoparticles (AuNP/rGO). The AuNPs/rGO nanocomposite was synthesized by co-reduction of Au(III) and graphene oxide and characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The response of the modified GCE to melamine was investigated by using hexacyanoferrate as an electrochemical reporter. It is found that the electrochemical response to hexacyanoferrate is increasingly suppressed by increasing concentration of melamine. This is attributed to competitive adsorption of melamine at the AuNP/rGO composite through the interaction between the amino groups of melamine and the AuNPs. The presence of rGO, in turn, provides a platform for a more uniform distribution of the AuNPs and enhances the electron transfer rate of the redox reaction. The findings were used to develop a sensitive method for the determination of melamine. Under optimized conditions, the redox peak current of hexacyanoferrate at a working voltage of 171 mV (vs. SCE) is linearly related to the concentration of melamine in 5.0 to 50 nM range. The method was successfully applied to the determination of melamine in food contact materials.
Co-reporter:Xinhao Shi, Wei Gu, Weidong Peng, Bingyu Li, Ningning Chen, Kai Zhao, and Yuezhong Xian
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 4) pp:2568
Publication Date(Web):January 29, 2014
DOI:10.1021/am405012k
A novel strategy was developed for fluorescent detection of Pb2+ in aqueous solution based on the fact that graphene oxide (GO) could quench the fluorescence of amino pyrene (AP)-grafted gold nanoparticles (AP–AuNPs) and Pb2+ could accelerate the leaching rate of AuNPs in the presence of S2O32–. In this system, fluorescence reporter AP was grafted on AuNPs through the Au–N bond. In the presence of GO, the system shows fluorescence quenching because of π–π stacking between AP and GO. With the addition of Pb2+ and S2O32–, the system displays fluorescence recovery, which is attributed to the fact that Pb2+ could accelerate the leaching of the AuNPs from GO surfaces and release of AP into aqueous solution. Interestingly, the concentration of GO could control the fluorescence “turn-off” or “turn-on” for Pb2+ detection. In addition, GO is also an excellent promoter for the acceleration of the leaching of AuNPs and shortening the analytical time to ∼15 min. Under the optimal conditions, the fluorescence Pb2+ sensor shows a linear range from 2.0 × 10–9 to 2.3 × 10–7 mol/L, with a detection limit of 1.0 × 10–10 mol/L.Keywords: amino pyrene; fluorescence sensor; gold nanoparticles; graphene oxide; Pb2+;
Co-reporter:Yixuan Zhang, Yuxiao Cheng, Ningning Chen, Yuyan Zhou, Bingyu Li, Wei Gu, Xinhao Shi, Yuezhong Xian
Journal of Colloid and Interface Science 2014 Volume 421() pp:85-92
Publication Date(Web):1 May 2014
DOI:10.1016/j.jcis.2014.01.022
•rGO-MNPs with tunable MNPs were synthesized for adsorption of BPA.•rGO-MNPs with lower density of MNPs showed better adsorption ability for BPA.•Adsorption kinetics fitted to a pseudo-second-order model.•Thermodynamics revealed the adsorption process was spontaneous and exothermal.•rGO-MNPs could be used as recyclable adsorbents for BPA due to superparamagnetism.Reduced graphene oxide (rGO) nanosheets decorated with tunable magnetic nanoparticles (MNPs) were synthesized by a simple co-precipitation method and employed for recyclable removal of bisphenol A (BPA) from aqueous solution. The morphological characterization shows that Fe3O4 nanoparticles are uniformly deposited on rGO sheets. The magnetic characterization demonstrates that composites with various amounts of Fe3O4 nanoparticles are superparamagnetic. Due to the superparamagnetism, rGO-MNPs were used as recyclable adsorbents for BPA removal in aqueous solution. The kinetics of the adsorption process and the adsorption isotherm were investigated. The results indicate that the adsorption process is fitted to Langmuir model and the composites with lower density of MNPs represent better adsorption ability. In addition, its kinetics follows pseudo-second-order rate equation. Moreover, the adsorbents could be recovered conveniently by magnetic separation and recyclable used because of the easy desorption of BPA.Graphical abstract
Co-reporter:Xinhao Shi;Wei Gu;Bingyu Li;Ningning Chen;Kai Zhao
Microchimica Acta 2014 Volume 181( Issue 1-2) pp:1-22
Publication Date(Web):2014 January
DOI:10.1007/s00604-013-1069-5
Over the past decades, various techniques have been developed to obtain materials at a nanoscale level to design biosensors with high sensitivity, selectivity and efficiency. Metal oxide nanoparticles (MONPs) are of particular interests and have received much attention because of their unique physical, chemical and catalytic properties. This review summarizes the progress made in enzymatic biosensors based on the use of MONPs. Synthetic methods, strategies for immobilization, and the functions of MONPs in enzymatic biosensing systems are reviewed and discussed. The article is subdivided into sections on enzymatic biosensors based on (a) zinc oxide nanoparticles, (b) titanium oxide nanoparticles, (c) iron oxide nanoparticles, and (d) other metal oxide nanoparticles. While substantial advances have been made in MONPs-based enzymatic biosensors, their applications to real samples still lie ahead because issues such as reproducibility and sensor stability have to be solved. The article contains 256 references.
Co-reporter:Wenjing Zhang, Xinhao Shi, Yixuan Zhang, Wei Gu, Bingyu Li and Yuezhong Xian
Journal of Materials Chemistry A 2013 vol. 1(Issue 5) pp:1745-1753
Publication Date(Web):21 Nov 2012
DOI:10.1039/C2TA00294A
In this work, graphene oxide/Fe3O4 (GO/Fe3O4) composites were synthesized via a copper catalyzed azide-alkyne cycloaddition reaction for the first time. After further modification with polyacrylic acid (PAA), water-soluble magnetic graphene nanocomposites were obtained. The PAA/GO/Fe3O4nanocomposites were characterized by atomic force microscopy, transmission electron microscopy, X-ray diffraction, Raman, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometry. Due to the high surface area, excellent complex ability and superparamagnetism, the PAA/GO/Fe3O4 nanocomposites were used as nanoadsorbents for recyclable removal of Cu2+, Cd2+ and Pb2+ ions from aqueous solution. It is found that the PAA/GO/Fe3O4 nanocomposites show extraordinary removal capacity for Cu2+, Cd2+ and Pb2+ ions. Moreover, the PAA/GO/Fe3O4 nanocomposites are very easy to separate and recycle due to the superparamagnetism of Fe3O4. After five cycles, the removal efficacy of the nanoadsorbents for Cu2+, Cd2+ and Pb2+ ions is over 85%. All of the results demonstrate that the water-soluble magnetic graphene composites are effective adsorbents for removal of heavy metals and thus could provide a new platform for water cleanup.
Co-reporter:Bingyu Li, Xinhao Shi, Wei Gu, Kai Zhao, Ningning Chen and Yuezhong Xian
Analyst 2013 vol. 138(Issue 23) pp:7212-7217
Publication Date(Web):24 Sep 2013
DOI:10.1039/C3AN01483E
In this paper, we report a simple, ultrasensitive and label-free method to evaluate the activity of protein tyrosine (Tyr) kinase based on the electrochemical signal of Tyr residues at a graphene modified glassy carbon electrode. It was found that graphene could enhance the electrochemical response of Tyr through electrocatalytic oxidation reaction. After phosphorylation by kinase, the phosphorylated Tyr (pTyr) is electro-inactive and the electrochemical signal is reduced. Therefore, the electrochemical response of Tyr residues in peptides can be used as a signal reporter to assay kinase activity. In this study, using Src-catalyzed Tyr-phosphorylation as a model, the activity of kinase can be evaluated with a linear range from 0.26 to 33.79 nM and an extraordinarily low detection limit of 0.087 nM. Moreover, this electrochemical biosensor can also be utilized for monitoring the inhibition of kinase using 4-amino-5-(4-chlorophenyl)-7-(tert-butyl) pyrazolo [3,4-d] pyrimidine, a small molecule inhibitor. On the basis of the inhibitor concentration dependent Tyr oxidation signal, the IC50 value was estimated to be 99 nM.
Co-reporter:Yanjun Lai;Jing Bai;Wei Zhu;Litong Jin
Chinese Journal of Chemistry 2013 Volume 31( Issue 2) pp:221-229
Publication Date(Web):
DOI:10.1002/cjoc.201200805
Abstract
Phenylethanolamine A (PEA), a β-agonist, was found to be illegally used as a growth promoter in pigs last year, causing Chinese government's great attention. Here, a sensitive electrochemical method was developed for detecting PEA by immobilization of gold nanoparticles (AuNPs), multiwalled carbon nanotubes (MWCNTs) and Nafion on the surface of a glassy carbon electrode (GCE). The Nafion/MWCNTs/AuNPs film was characterized by scanning electronic micrographs (SEM) and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of PEA at the modified GCE were investigated in detail. The synergetic effects of AuNPs, MWCNTs and Nafion amplify the electrochemical reduction signal of PEA, and result in high sensitivity for PEA determination. Under the optimal conditions, the electrochemical sensor shows a wide linear range of 0.01 to 10 (mol/L with a detection limit of 0.005 µmol/L. Moreover, the fabricated sensor presents high selectivity and long-term stability, which paves a new way for simple, rapid, sensitive detection of PEA.
Co-reporter:Yixuan Zhang, Yuxiao Cheng, Yuyan Zhou, Bingyu Li, Wei Gu, Xinhao Shi, Yuezhong Xian
Talanta 2013 Volume 107() pp:211-218
Publication Date(Web):30 March 2013
DOI:10.1016/j.talanta.2013.01.012
Bisphenol A (BPA), as one kind of endocrine-disrupting chemicals, has adverse impact on human health and environment. It is urgent to develop effective and simple methods for quantitative determination of BPA. In this work, an electrochemical sensor for BPA based on magnetic nanoparticles (MNPs)-reduced graphene oxide (rGO) composites and chitosan was presented for the first time. The MNPs-rGO composites were characterized by scanning electron microscopy, X-Ray diffraction and Fourier transform infrared spectroscopy. Electrochemical studies show that MNPs-rGO composites can lower the oxidation overpotential and enhance electrochemical response of BPA due to the synergetic effects of MNPs and rGO. Under the optimal experiment conditions, the oxidation peak current was proportional to the concentration of BPA over the range of 6.0×10−8 to 1.1×10−5 mol L−1 with the detection limit of 1.7×10−8 mol L−1. Moreover, the MNPs-rGO based electrochemical sensor shows excellent stability, reproducibility and selectivity. The electrochemical sensor has been successfully applied to the determination of BPA in real samples with satisfactory results.Highlights► Fe3O4-rGO was synthesized and used as electrode matrix. ► Electrocatalytic oxidization of BPA was realized by Fe3O4-rGO. ► Sensitivity was improved due to the synergetic effects of Fe3O4 and rGO. ► Sensitive analysis of BPA in six real samples has been performed.
Co-reporter:Yanjun Lai, Jing Bai, XinHao Shi, Yanbo Zeng, Yuezhong Xian, Jie Hou, Litong Jin
Talanta 2013 Volume 107() pp:176-182
Publication Date(Web):30 March 2013
DOI:10.1016/j.talanta.2013.01.002
A novel electrochemical immunosensor for sensitive detection of clenbuterol (CLB) is fabricated using glucose oxidase (GOD)-functionalized grahene oxide (GO) nanocomposites to label CLB. The immunosensor was constructed by layer-by-layer assembly colloidal prussian blue (PB), multiwalled carbon nanotubes (MWCNTs) and CLB antibodies (Abs) on a glassy carbon electrode (GCE). In this competitive immunoassay system, PB acts as the redox mediator to reduce H2O2 originated from the catalyst cycle of GOD. The high ratio of GOD to GO effectively amplified the signal for this competitive-type immunoassay. Under optimized conditions, the immunosensor shows a wide linear range from 0.5 to 1000 ng/mL with a low detection limit of 0.25 ng/mL. The dual signal amplification of GOD-functionalized GO nanocomposites as a label is promising to be applied to design other sensitive immunosenseors.Highlights► Labeling amplification strategy was used to construct the clenbuterol immunosensor. ► Gold nanoparticles decorated graphene oxide was utilized as a nanocarrier. ► The circles directed by glucose oxide and Prussian blue dually amplified signal. ► The proposed immunosensor achieves high sensitivity and a low detection limit.
Co-reporter:Siqiu Ye, Xinhao Shi, Wei Gu, Yixuan Zhang and Yuezhong Xian
Analyst 2012 vol. 137(Issue 14) pp:3365-3371
Publication Date(Web):08 May 2012
DOI:10.1039/C2AN35311C
A colorimetric sensor for Cu(II) ions has been developed based on mixed self-assembled monolayers (SAMs) modified gold nanoparticles (AuNPs). The AuNPs were modified with mixed SAMs consisting of mercaptosuccinic acid and the product of electrochemically triggered Michael addition reaction of 4-thiouracil and catechol. In the presence of Cu(II) ions, the coordination of Cu2+ to catechol-terminated AuNPs leads to aggregation-induced changes of surface plasmon resonance. The cost-effective chemical sensor allows rapid, sensitive and selective detection of Cu2+ ions, indicating its potential application in environmental field.
Co-reporter:Li Jing, Cong Liang, Xinhao Shi, Siqiu Ye and Yuezhong Xian
Analyst 2012 vol. 137(Issue 7) pp:1718-1722
Publication Date(Web):22 Feb 2012
DOI:10.1039/C2AN16152D
The attempt to decorate carbon nanotubes with organic molecules to form new functional materials has attracted broad attention in the scientific community. Here, we report the covalent functionalization of multiwalled carbon nanotubes (MWCNTs) with pyrene via Cu(I)-catalysed azide/alkyne click (CuAAC) reactions under mild conditions to afford the nanocomposites of pyrene–MWCNTs. Fourier transform infrared spectroscopy (FT-IR), ultraviolet and visible spectroscopy (UV-Vis), and fluorescence spectroscopy were used to characterize the nanocomposites of pyrene clicked MWCNTs. Experimental results indicate that the CuAAC reaction occurs in an efficient manner and the spacer linking MWCNTs and the photoactive molecule is well defined. In contrast to the noncovalent functionalization of π–π stacking, the nanocomposites of pyrene clicked MWCNTs show relatively strong fluorescence and have potential applicability in photoluminescent devices as a highly sensitive and selective fluorescence “turn-off” sensor for Fe3+.
Co-reporter:Jing Bai, Yanjun Lai, Dawei Jiang, Yanbo Zeng, Yuezhong Xian, Fei Xiao, Ningdan Zhang, Jie Hou and Litong Jin
Analyst 2012 vol. 137(Issue 18) pp:4349-4355
Publication Date(Web):25 Jun 2012
DOI:10.1039/C2AN35473J
We report the development of an ultrasensitive amperometric biosensor based on Ag nanoparticles-decorated graphene oxide nanosheets (GO) (Ag–GO) for the rapid detection of clenbuterol (CLB). The morphology and structure of the Ag–GO labeled CLB (Ag–GO–CLB) were characterized by transmission electron microscope (TEM), atomic force microscope (AFM), and ultraviolet-visible spectroscope (UV-vis). The immunosensor was prepared by covalently immobilizing capture antibodies on a multi-walled carbon nanotubes-modified glassy carbon electrode. Through competitive immunoreactions, the Ag–GO–CLB nanocomposites were captured on the immunosensor and the silver was measured by positive differential pulse voltammetry (DPV) in KCl solution for the detection of antigen. The experimental results show a linear response over the range from 0.01 to 10.0 ng mL−1 with a lower detection limit of 6.8 pg mL−1 (signal-to-noise ratio of 3). The Ag–GO based immunosensor offers a simple and convenient route for metal-immunoassay labels, which can avoid the complicated and time-consuming dissolving of metal component for ultrasensitive determination. Moreover, the electrochemical immunoassay shows acceptable specificity and stability and is suitable for the determination of CLB in real samples.
Co-reporter:Fei Xiao;Yanjun Lai;Ningdan Zhang;Jing Bai;Litong Jin
Chinese Journal of Chemistry 2012 Volume 30( Issue 5) pp:1168-1176
Publication Date(Web):
DOI:10.1002/cjoc.201100548
Abstract
A photoelectrochemical immunosensor based on multi-electrode array was developed for simultaneous and sensitive determination of veterinary drug residues. In this system, poly(dimethyldiallylammonium chloride) (PDDA), Au nanoparticles (Au NPs) and thioglycolic acid (TGA)-capped CdS quantum dots (QDs) were layer-by-layer assembled onto the home-made Au electrode array. The assembling process of the (CdS/PDDA/Au NPs/PDDA)n multilayer was characterized by electrochemical impedance spectroscopy. And then the antibodies for clenbuterol (CB), ractopamine (RAC) and chloramphenicol (CAP) were covalently immobilized onto the Au electrode array by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) coupling reaction, respectively. The concentrations of CB, RAC and CAP were measured based on the photoelectrochemical effects of CdS QDs. Under the optimal conditions, the limits of detection (LOD) for CB, RAC and CAP were 25, 50 and 2.2 pg/mL (3Δ), respectively, with acceptable recovery over the range of 95.40%–105.5% in pig liver samples. All results indicate that the immunosensor array system has potential application for practical, effective and high throughput analysis of veterinary drugs residues.
Co-reporter:Wenjing Zhang;Xinhao Shi;Dr. Jing Huang;Yixuan Zhang; Zirong Wu; Yuezhong Xian
ChemPhysChem 2012 Volume 13( Issue 14) pp:3388-3396
Publication Date(Web):
DOI:10.1002/cphc.201200161
Abstract
Bacitracin-conjugated superparamagnetic iron oxide (Fe3O4) nanoparticles were prepared by click chemistry and their antibacterial activity was investigated. After functionalization with hydrophilic and biocompatible poly(acrylic acid), water-soluble Fe3O4 nanoparticles were obtained. Propargylated Fe3O4 nanoparticles were then synthesized by carbodiimide reaction of propargylamine with the carboxyl groups on the surface of the iron oxide nanoparticles. By further reaction with N3-bacitracin in a CuI-catalyzed azide–alkyne cycloaddition, the magnetic Fe3O4 nanoparticles were modified with the peptide bacitracin. The functionalized magnetic nanoparticles were characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, TEM, zeta-potential analysis, FTIR spectroscopy and vibrating-sample magnetometry. Cell cytotoxicity tests indicate that bacitracin-conjugated Fe3O4 nanoparticles show very low cytotoxicity to human fibroblast cells, even at relatively high concentrations. In view of the antibacterial activity of bacitracin, the biofunctionalized Fe3O4 nanoparticles exhibit an antibacterial effect against both Gram-positive and Gram-negative organisms, which is even higher than that of bacitracin itself. The enhanced antibacterial activity of the magnetic nanocomposites allows the dosage and the side effects of the antibiotic to be reduced. Due to the antibacterial effect and magnetism, the bacitracin-functionalized magnetic nanoparticles have potential application in magnetic-targeting biomedical applications.
Co-reporter:Wenjing Zhang, Yixuan Zhang, Xinhao Shi, Cong Liang and Yuezhong Xian
Journal of Materials Chemistry A 2011 vol. 21(Issue 40) pp:16177-16183
Publication Date(Web):13 Sep 2011
DOI:10.1039/C1JM12353J
The paper reports on covalent clicking of rhodamine-B (RhB) bearing a terminal azide group to alkyne-terminated silica coated superparamagnetic iron oxide nanoparticlesvia the copper(I)-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction. The course of the reaction was followed the use of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, fluoroscopy, and magnetics. The RhB labelled Fe3O4@SiO2 nanoparticles exhibit stable fluorescence and no detectable leakage of the fluorescent dye because the resulting 1,4-disubstituted 1,2,3-triazole ring formed via click reaction is thermally stable and relatively inert to hydrolysis, oxidation, and reduction. Due to the superparamagnetic property of the Fe3O4 and the RhB molecule covalently decorated in the Fe3O4@SiO2 framework, the nanoparticles are endowed with properties of a contrast agent in magnetic resonance imaging (MRI) and optical imaging modality. The cytotoxicity tests indicate the bifunctional nanoparticles could be applied in biomedical or bioengineering field.
Co-reporter:Qin Ran, Ru Peng, Cong Liang, Siqiu Ye, Yuezhong Xian, Wenjing Zhang, Litong Jin
Analytica Chimica Acta 2011 Volume 697(1–2) pp:27-31
Publication Date(Web):4 July 2011
DOI:10.1016/j.aca.2011.04.035
In this paper, a simple two-step approach for redox protein immobilization was introduced. Firstly, alkynyl-terminated film was formed on electrode surface by electrochemical reduction of 4-ethylnylphenyl (4-EP) diazonium compound. Then, horseradish peroxidase (HRP) modified with azido group was covalently immobilized onto the electrografted film via click reaction. Reflection absorption infrared (RAIR) spectroscopy and electrochemical methods were used to characterize the modification process. The results indicate that HRP retains its native structure and shows fast direct electron transfer. Moreover, the immobilized HRP shows excellent electrocatalytic reduction activity toward H2O2 with a linear range of 5.0 × 10−6 to 9.3 × 10−4 mol L−1.Graphical abstractHydrogen peroxide biosensor was developed based on electrochemically assisted aryldiazonium salt chemistry and click chemistry.Highlights► A simple, versatile two-step approach, which is based on electrochemically assisted aryldiazonium salt chemistry and Cu(I)-catalyzed azide alkyne cycloaddition (CuAAC) reaction has been developed for covalent redox proteins immobilization and biosensing for the first time. In this work, azido group modified HRP was covalently grafted on 4-ethylnylphenyl diazonium compound via CuAAC reaction and a novel electrochemical hydrogen peroxide biosensor was successfully fabricated.
Co-reporter:Yuan Tian, Siqiu Ye, Xinhao Shi, Li Jing, Cong Liang and Yuezhong Xian
Analyst 2011 vol. 136(Issue 23) pp:5084-5090
Publication Date(Web):13 Oct 2011
DOI:10.1039/C1AN15601B
An electrochemical platform for acetylcholinesterase (AChE) activity assay and its inhibitors screening is developed based on the Michael addition reaction of thiocholine, the hydrolysis product of acetylthiocholine (AsCh) in the presence of AChE, with the electrogenerated o-quinone of catechol-terminated SAMs on a gold electrode. For understanding and confirming the mechanism of the reaction, the electrochemical behaviors of Michael addition reaction of two model compounds, cysteine (CYS) and glutathione (GSH), towards the catechol-terminated SAMs have been studied. The enzyme kinetics and the inhibition effects of three types of AChE inhibitors, which are tacrine, carbofuran and parathion-methyl, have been investigated using an amperometric method. Among these three inhibitors, tacrine exhibits the strongest inhibiting effect, which is reinforced by the resulting data of kinetic studies on each inhibitor's influence upon the enzyme activity.
Co-reporter:Ru Peng, Wenjing Zhang, Qin Ran, Cong Liang, Li Jing, Siqiu Ye, and Yuezhong Xian
Langmuir 2011 Volume 27(Issue 6) pp:2910-2916
Publication Date(Web):February 7, 2011
DOI:10.1021/la1040486
A simple and versatile method for the introduction of redox unites onto the surface of magnetic nanoparticles has been developed based on “click” chemistry. Azide-functionalized Fe2O3 magnetic nanoparticles were synthesized and further reacted with ethynylferrocene via Cu(I)-catalyzed azide alkyne 1,3-dipolar cycloaddition (CuAAC) reaction. The functionalized magnetic nanoparticles were characterized using a powder X-ray diffractometer (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscope (FTIR), and vibrating sample magnetometer (VSM). The resulting materials have properties of both magnetism and electrochemistry, and the electrochemical properties of the nanoparticles are dependent on the features of ethynylferrocene, while the magnetic properties remain independent of ethynylferrocene. Because of the magnetism of Fe2O3 nanoparticles and the electrocatalytic activity of ferrocene unites, a recyclable, magneto-switchable bioelectrocatalytic system for glucose oxidation in the presence of glucose oxidase is developed by alternate positioning of an external magnet, and the system has a linear response for glucose biosensing over the range of 1.0−10.0 mM.
Co-reporter:Qin Ran, Ru Peng, Cong Liang, Siqiu Ye, Yuezhong Xian, Wenjing Zhang, Litong Jin
Talanta 2011 Volume 83(Issue 5) pp:1381-1385
Publication Date(Web):15 February 2011
DOI:10.1016/j.talanta.2010.11.024
A simple and versatile approach for covalent immobilization of redox protein on solid surface via self-assembled technique and click chemistry is reported. The alkynyl-terminated monolayers are obtained by self-assembled technique, then, azido-horseradish peroxidase (azido-HRP) was covalent immobilized onto the formed monolayers by click reaction. The modified process is characterized by reflection absorption infrared spectroscopy (RAIR), surface-enhanced Raman scattering spectroscopy (SERS) and electrochemical methods. All the experimental results suggest that HRP is immobilized onto the electrode surface successfully without denaturation. Furthermore, the immobilized HRP shows electrocatalytic reduction for H2O2, and the linear range is from 5.0 to 700 μM. The heterogeneous electron transfer rate constant ks is 1.11 s−1 and the apparent Michaelis–Menten constant is calculated to be 0.196 mM.
Co-reporter:Zhichao Hu, Jingjing Xu, Yuan Tian, Ru Peng, Yuezhong Xian, Qin Ran, Litong Jin
Carbon 2010 Volume 48(Issue 13) pp:3729-3736
Publication Date(Web):November 2010
DOI:10.1016/j.carbon.2010.06.035
A simple and versatile method based on noncovalent supramolecular attachment and layer-by-layer (LBL) assembly is proposed to prepare nanostructured hybrid conducting polymer. The negatively charged poly(sodium 4-styrenesulfonate) (PSS) wrapped multiwalled carbon nanotubes (MWCNTs) is doped with cationic polyaniline (PANI) nanofibers via LBL assembly, and a well-defined PANI/MWCNTs composite was obtained. The LBL assembly process is characterized by scanning electron microscopy, energy dispersive spectrometry and electrochemical methods. It was found that PSS wrapped MWCNTs inside the multilayer film can dope nanostructured PANI effectively and shift its electroactivity to a neutral pH environment. Moreover, the conducting composites show amperometric response for hydrogen peroxide with a linear range of 2.0 × 10−7–1.0 × 10−3 mol L−1.
Co-reporter:Yuan Tian, Siqiu Ye, Qin Ran, Yuezhong Xian, Jingjing Xu, Ru Peng and Litong Jin
Physical Chemistry Chemical Physics 2010 vol. 12(Issue 40) pp:13287-13295
Publication Date(Web):09 Sep 2010
DOI:10.1039/C001205J
In this paper, catechol, 1,4-dihydroxybenzene and dopamine are investigated as precursors of electrophiles for Michael addition reaction with the self-assembled monolayer (SAM) of 4-thiouracil (4-TU) via electrochemical triggering. All compounds can undergo Michael addition reaction with 4-TU; however, only catechol can react with 4-TU with high efficiency. The catechol-terminated SAMs, via electrochemically triggered Michael addition reaction, exhibit reversible redox response. In addition, we find that catechol-terminated SAMs can complex with Ni2+ and Cu2+ with different electrochemical behaviors. Moreover, the mechanism of complexation of Ni2+and Cu2+ with catechol-terminated SAMs is also demonstrated with electrochemical and spectrometric methods. Based on the different electrochemical behaviors of Cu2+ and Ni2+ complex, the catechol-terminated SAMs provide a potential platform for metal ions recognition.
Co-reporter:JingJing Xu, Ru Peng, Qin Ran, Yuezhong Xian, Yuan Tian, Litong Jin
Talanta 2010 Volume 82(Issue 4) pp:1511-1515
Publication Date(Web):15 September 2010
DOI:10.1016/j.talanta.2010.07.033
A highly soluble poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)/Au (PEDOT-PSS/Au) nanocomposite was prepared via one-step chemical synthesis and the matrix was characterized by UV–vis spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscope (TEM). Due to the excellent aqueous compatibility and biocompatibility, the PEDOT/PSS-Au nanocomposite can be used as biomaterial for enzymes immobilization. In this system, redox enzyme, horseradish peroxidase (HRP) was integrated with PEDOT/PSS-Au nanocomposite and the direct electron transfer of HRP was observed. Moreover, we find that the HRP/PEDOT-PSS/Au modified electrode shows excellent electrocatalytic ability for H2O2 and the formal Michaelis–Menten constant (Kmapp) was 0.78 mmol/L. The response currents have good linear relation with the concentrations of H2O2 with a linear range from 2.0 × 10−7 to 3.8 × 10−4 mol/L.
Co-reporter:Liwei Wang;Qin Ran;Yuan Tian;Siqiu Ye;Jingjing Xu
Microchimica Acta 2010 Volume 171( Issue 3-4) pp:217-223
Publication Date(Web):2010 December
DOI:10.1007/s00604-010-0433-y
A stepwise strategy is reported for the design of a meditor-free amperometric tyrosinase biosensor. It is based on the azide-alkyne click reaction and carbodiimide coupling. Firstly, azide-terminated alkane thiols monolayers were self-assembled on the Au electrode surface. Then, nitrophenyl groups were covalent attached to the self-assembled monolayers (SAMs) via the click reaction of copper(I)-catalyzed 1,3-dipolar cycloadditions of azide-alkyne. Finally, the nitrophenyl group terminated SAMs were converted to aminophenyl-terminated interface by electrochemical reduction, and tyrosinase was covalent immobilized onto the Au electrode via carbodiimide reaction. Based on the stepwise strategy, a meditor-free amperometric tyrosinase biosensor was farbricated, and it showed good electrocatalytic reduction ability toward phenol, pyrocatechol and m-Cresol. Their linear ranges were over the range of 0.2 to 15.0 μmol·L−1, 0.2 to 73.0 μmol·L−1, and 0.2 to 33.0 μmol·L−1, respectively.
Co-reporter:Zhichao Hu, Jingjing Xu, Yuan Tian, Ru Peng, Yuezhong Xian, Qin Ran, Litong Jin
Electrochimica Acta 2009 Volume 54(Issue 16) pp:4056-4061
Publication Date(Web):30 June 2009
DOI:10.1016/j.electacta.2009.02.032
Polyaniline (PANI) nanofibers are synthesized by dilute polymerization and subsequently used for layer-by-layer assembly with poly(acrylic acid) (PAA). The chemical synthesized PANI nanofibers are characterized by SEM and TEM. In addition, the LBL assembly process is characterized by SEM, UV–vis spectrometry and electrochemical methods. PAA inside the multilayer film can dope nanostructured PANI effectively and shift its electroactivity to a neutral pH environment. Compared with PANI/PAA film co-deposited on the electrode by electropolymerization, the redox behavior of PANI/PAA multilayer via LBL assembly is more reversible, indicating the enhancement of electron transfer. The obtained nanostructured PANI/PAA multilayer films are very stable and show high electrocatalytic ability toward H2O2, which makes it an ideal substrate for H2O2 detection and offers great promise for biosensing.
Co-reporter:Liwei Wang, Yuan Tian, Qin Ran, Zhichao Hu, Jingjing Xu, Yuezhong Xian, Ru Peng, Litong Jin
Electrochemistry Communications 2009 Volume 11(Issue 2) pp:339-342
Publication Date(Web):February 2009
DOI:10.1016/j.elecom.2008.12.009
In this paper, we described a simple and facile method for the covalent functionalization of Au surface with nitrophenyl group via stepwise strategy. Structurally well-defined azide-terminated organic self-assembled monolayers (SAMs) were formed on Au surface from a commercially available mixture solution of azidoundecanethiol and dilute thiol. Subsequent, derivatization of the azide-terminated monolayers was conducted in aqueous environments with ethynyl nitrobenzene via a selective, reliable, robust click reaction. By this way, the nitrophenyl group was covalently and quantitatively grafted on Au surface, which was confirmed by Raman Spectrometry and electrochemical methods. These results demonstrated the efficiency of using click chemistry in assembling covalently linked nanostructures.
Co-reporter:Jingjing Xu, Yuan Tian, Ru Peng, Yuezhong Xian, Qin Ran, Litong Jin
Electrochemistry Communications 2009 Volume 11(Issue 10) pp:1972-1975
Publication Date(Web):October 2009
DOI:10.1016/j.elecom.2009.08.031
The “click” chemistry, Cu(I)-catalyzed azide–alkyne cycloaddition reaction, was applied to covalently functionalize the poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer film with an excellent electron transfer mediator (ferrocene). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy were used to characterize the ferrocene-grafted PEDOT conducting polymer film, and it was proved that the grafting procedure via click reaction had a high efficiency. The ferrocene groups covalently grafted in the polymer films turned out to own a relatively fast electron transfer rate and show multi-color states via adjusting applied potential.
Co-reporter:Yuan Tian;Qin Ran;Jingjing Xu, ;Ru Peng ;Litong Jin
ChemPhysChem 2009 Volume 10( Issue 17) pp:3105-3111
Publication Date(Web):
DOI:10.1002/cphc.200900588
Abstract
Herein, we report a versatile surface chemistry methodology to covalently immobilize ligands and proteins to self-assembled monolayers (SAMs) on gold electrode. The strategy is based on two steps: 1) the coupling of soluble azido-PEG-amimo ligand with an alkynyl-terminated monolayer via click reaction and 2) covalent immobilization hemoglobin (Hb) to the amine-terminated ligand via carbodiimide reaction. Surface-enhanced Raman scattering spectroscopy (SERS), atomic force microscopy (AFM), reflection absorption infrared spectroscopy (RAIR) and cyclic voltammetry are used to characterize the model interfacial reactions. We also demonstrate the excellent biocompatibility of the interface for Hb immobilization and reliable application of the proposed method for H2O2 biosensing. Moreover, the redox thermodynamics of the Fe3+/Fe2+ couple in Hb is also investigated.
Co-reporter:Linjie Feng;Liwei Wang;Zhichao Hu;Yuan Tian
Microchimica Acta 2009 Volume 164( Issue 1-2) pp:49-54
Publication Date(Web):2009 January
DOI:10.1007/s00604-008-0030-5
A biohybrid hydrogel is fabricated by integrating horseradish peroxidase (HRP) with polyhydroxyl cellulose (PHC), which is prepared by mixing of poly(vinyl alcohol) and carboxymethyl hydroxyethyl cellulose. PHC provides a biocompatible microenvironment for HRP, and the UV-vis spectrum indicates that the confromation of HRP-loaded biohydrogel is well retained relative to free HRP. Based on the direct electrochemistry and electrocatalytic ability of HRP, a third-generation H2O2 biosensor is developed. Under the optimized conditions, the H2O2 biosensor shows a linear response over the range from 1.0 μM to 1.0 mM with a detection limit (S/N = 3) of 0.5 μM.
Co-reporter:Fanghua Wu, Zhichao Hu, Jingjing Xu, Yuan Tian, Liwei Wang, Yuezhong Xian, Litong Jin
Electrochimica Acta 2008 Volume 53(Issue 28) pp:8238-8244
Publication Date(Web):30 November 2008
DOI:10.1016/j.electacta.2008.06.031
Highly organized (3-mercaptopropyl)trimethoxysilane (3-MPT) films have been prepared via self-assembled coupled with sol–gel linking technology. Horseradish peroxidase (HRP) is successfully immobilized onto the densely packed three-dimensional (3D) 3-MPT network and the direct electrochemistry of HRP is achieved without any electron mediators or promoters. Redox thermodynamics of HRP on the 3-MPT films, which is obtained from the temperature dependence of the reduction potential, suggests that the positive shift of redox potentials of HRP at the interface of 3-MPT originates from the solvent reorganization effects and conformational change of the polypeptide chain of HRP. Based on the direct electrochemistry and electrocatalytic ability of HRP, a sensitive third-generation amperometric H2O2 biosensor is developed with two linear dependence ranges of 5.0 × 10−7 to 1.0 × 10−4 and 1.0 × 10−4 to 2.0 × 10−2 mol L−1.
Co-reporter:Fanghua Wu, Zhichao Hu, Liwei Wang, Jingjing Xu, Yuezhong Xian, Yuan Tian, Litong Jin
Electrochemistry Communications 2008 Volume 10(Issue 4) pp:630-634
Publication Date(Web):April 2008
DOI:10.1016/j.elecom.2008.01.020
A novel method based on electric field directed layer-by-layer assembly (EFDLA) and template synthesis is successfully developed to fabricate horseradish peroxidase (HRP) nanotubes. It provides a rapid and general strategy for functional protein nanoarrays. The alternative deposition of poly(diallyldimethylammonium chloride) (PDDA) and HRP are characterized by SEM, TEM, UV–vis and electrochemical impedance spectroscopy (EIS). Moreover, the UV–vis spectrometry and electrochemistry of HRP indicate that immobilization of PDDA/HRP via EFDLA coupled with template synthesis could retain the conformations and bioactivities of HRP.
Co-reporter:Fanghua Wu, Jingjing Xu, Yuan Tian, Zhichao Hu, Liwei Wang, Yuezhong Xian, Litong Jin
Biosensors and Bioelectronics 2008 Volume 24(Issue 2) pp:198-203
Publication Date(Web):15 October 2008
DOI:10.1016/j.bios.2008.03.031
Horseradish peroxidase (HRP) was successfully immobilized on vertically oriented TiO2 nanotube arrays (NTAs), which was prepared by a seeded-growth mechanism. The nanotubular structure of TiO2 was characterized by scanning electron microscope (SEM). After encapsulated HRP on TiO2 nanotube arrays, the direct electron transfer of HRP was observed. Owing to the redox reaction of electroactive center of HRP, the HRP/TiO2 NTAs modified electrode exhibited a pair of quasi-reversible peaks with the peak-to-peak separation of 70 mV and the formal potential of −0.122 V (vs. SCE) in 0.2 mol L−1 phosphate buffer solution (PBS, pH 7.0). The number of transference electron was 0.84 and the direct electron transfer (ET) constant (ks) was 3.82 s−1. The HRP/TiO2 NTAs modified electrode displayed an excellent electrocatalytic performance for H2O2 and the formal Michaelis–Menten constant (Kmapp) was 1.9 mmol L−1. The response currents had a good linear relation with the concentration of H2O2 from 5.0 × 10−7 mol L−1 to 1.0 × 10−5 mol L−1 and 5.0 × 10−5 mol L−1 to 1.0 × 10−3 mol L−1, respectively.
Co-reporter:Yuezhong Xian, Yang Xian, Lihui Zhou, Fanghua Wu, Yun Ling, Litong Jin
Electrochemistry Communications 2007 Volume 9(Issue 1) pp:142-148
Publication Date(Web):January 2007
DOI:10.1016/j.elecom.2006.08.049
The encapsulation of hemoglobin (Hb) on the mesoporous silicas SBA-15 and Au-doped SBA-15 (Au-SBA-15) has been studied as a model protein adsorption system. The influences of solution pH, structure of mesoporous silicas and gold nanoparticles incorporation on Hb immobilization are investigated in detail. The spectral characteristics of Hb/SBA-15 and Hb/Au-SBA-15 nanoconjugate show an absorption curve quite similar to that of native Hb, indicating that Hb retains its higher-order structure in the mesopores of SBA-15. Direct electrochemistry of Hb is obtained when Hb is adsorpted by mesoporous silicas SBA-15 or Au-SBA-15. Moreover, Hb/Au-SBA-15 exerts enhancing electron transfer ability because of the Au incorporation. Additionally, the Hb/Au-SBA-15 displays good electrocatalytic reduction of hydrogen peroxide with a detection limit of 1.0 μM, about 3 times as low as that for the Hb/SBA-15. The Hb/Au-SBA-15 exhibits higher peroxidase-like activity with the apparent Michaelis–Menton constant (Km) of 2.87 mM, significantly lower than the 7.78 mM value for the Hb/SBA-15.
Co-reporter:Yuezhong Xian, Yi Hu, Fang Liu, Yang Xian, Linjie Feng, Litong Jin
Biosensors and Bioelectronics 2007 Volume 22(Issue 12) pp:2827-2833
Publication Date(Web):15 June 2007
DOI:10.1016/j.bios.2006.11.020
In this paper, we propose a strategy to form nanoelectrode arrays by electrochemical deposition of the Prussian blue (PB) through highly ordered porous anodic alumina (PAA) membrane. The structure and morphology of the nanoarrays were characterized by scanning electron microscopy (SEM). As the highly ordered PB arrays can behave as an ensemble of closely spaced but isolated nanoelectrodes, the nanostructured PB arrays are successfully applied to improve the analytical performances of glucose by electrocatalytic reduction enzymatically liberated H2O2. The resulting PB based nanoelectrode arrays show a wide linear calibration range over three orders of magnitude of glucose concentrations (5.0 × 10−6 to 8.0 × 10−3 M) and a low detection limit of 1 μM. Moreover, the biosensor exhibits other good characteristics, such as short response time, high selectivity, excellent operation stability. In addition, effects of the glucose oxidase (GOx) loading, applied potential and pH on the biosensor performance were also discussed.
Co-reporter:Yuezhong Xian, Yuyan Zhou, Yang Xian, Lihui Zhou, Haiting Wang, Litong Jin
Analytica Chimica Acta 2005 Volume 546(Issue 2) pp:139-146
Publication Date(Web):8 August 2005
DOI:10.1016/j.aca.2005.04.090
In this paper, a novel modified electrode was developed by using highly dispersed Prussian blue (PB) nanoparticles protected by poly(vinylpyrrolidone) (PVP). The size of the nanoparticles was controlled through adjusting the feed ratio of PVP/Fe2+. Physical characteristics of the nanocomposite were studied by transmission electron microscopy (TEM), UV–vis, IR spectroscopy, and X-ray powder diffraction (XRPD) analysis. The electrocatalytic reduction of hemoglobin (Hb) at PVP-protected PB nanoparticles (PVP/PB NPs)-modified electrode had been investigated. In addition, the size effects and biocompatibility of PVP/PB NPs for the electrochemistry of Hb were also observed. Experimental results indicated that the reduction peak currents of Hb were linear with its concentrations over the range from 1.0 × 10−7 to 1.2 × 10−5 mol/L and the calculated detection limit (S/N = 3) was 4.0 × 10−8 mol/L.
Co-reporter:Yuezhong Xian, Haiting Wang, Yuyan Zhou, Danmei Pan, Fang Liu, Litong Jin
Electrochemistry Communications 2004 Volume 6(Issue 12) pp:1270-1275
Publication Date(Web):December 2004
DOI:10.1016/j.elecom.2004.10.003
A novel method for fabricating a nanoarray electrode combining the template technique with the self-assembled approach was developed. The glassy carbon electrode was modified with the Au nanoarray using micropores of aluminum anodic film as template. Then, the Au nanoarray electrode was self-assembled with l-cysteine (l-Cys) and gold colloid, respectively. In order to evaluate the electrochemical characteristics of l-Cys–Au colloid self-assembled nanoarray electrode, Fe(CN)63- was chosen as molecule probe and cyclic voltammetry was used. In addition, the functional nanoarray electrode was applied to measuring dopamine (DA). The resulting l-Cys–Au colloid self-assembled nanoarray electrode demonstrated that the linear calibration range extended over three orders of magnitude of DA concentrations (1.0 × 10−9–1.0 × 10−6 mol/L) and the detection limit was 5.0 × 10−10 mol/L.
Co-reporter:Cuiling Zhang, Caiping Ding, Guohua Zhou, Qin Xue, Yuezhong Xian
Analytica Chimica Acta (8 March 2017) Volume 957() pp:
Publication Date(Web):8 March 2017
DOI:10.1016/j.aca.2016.12.024
•The stable and cadmium-free DNA functionalized ZnS:Mn2+ QDs were successfully synthesized through a facile one-step route.•We constructed a novel FRET system based on one-step synthesized DNA-ZnS:Mn2+ QDs (donor) and WS2 nanosheets (acceptor).•The FRET-based strategy was applied for the detection of streptavidin and folate receptor by combining TPSMLD and Exo III.DNA functionalized quantum dots (QDs) are promising nanoprobes for the fluorescence resonance energy transfer (FRET)-based biosensing. Herein, cadmium-free DNA functionalized Mn-doped ZnS (DNA-ZnS:Mn2+) QDs were successfully synthesized by one-step route. As-synthesized QDs show excellent photo-stability with the help of PAA and DNA. Then, we constructed a novel FRET model based on the QDs and WS2 nanosheets as the energy donor-acceptor pairs, which was successfully applied for the protein detection through the terminal protection of small molecule-linked DNA assay. This work not only explores the potential bioapplication of the DNA-ZnS:Mn2+ QDs, but also provides a platform for the investigation of small molecule-protein interaction.
Co-reporter:Wenjing Zhang, Xinhao Shi, Yixuan Zhang, Wei Gu, Bingyu Li and Yuezhong Xian
Journal of Materials Chemistry A 2013 - vol. 1(Issue 5) pp:NaN1753-1753
Publication Date(Web):2012/11/21
DOI:10.1039/C2TA00294A
In this work, graphene oxide/Fe3O4 (GO/Fe3O4) composites were synthesized via a copper catalyzed azide-alkyne cycloaddition reaction for the first time. After further modification with polyacrylic acid (PAA), water-soluble magnetic graphene nanocomposites were obtained. The PAA/GO/Fe3O4nanocomposites were characterized by atomic force microscopy, transmission electron microscopy, X-ray diffraction, Raman, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometry. Due to the high surface area, excellent complex ability and superparamagnetism, the PAA/GO/Fe3O4 nanocomposites were used as nanoadsorbents for recyclable removal of Cu2+, Cd2+ and Pb2+ ions from aqueous solution. It is found that the PAA/GO/Fe3O4 nanocomposites show extraordinary removal capacity for Cu2+, Cd2+ and Pb2+ ions. Moreover, the PAA/GO/Fe3O4 nanocomposites are very easy to separate and recycle due to the superparamagnetism of Fe3O4. After five cycles, the removal efficacy of the nanoadsorbents for Cu2+, Cd2+ and Pb2+ ions is over 85%. All of the results demonstrate that the water-soluble magnetic graphene composites are effective adsorbents for removal of heavy metals and thus could provide a new platform for water cleanup.
Co-reporter:Xinhao Shi, Wei Gu, Cuiling Zhang, Longyun Zhao, Weidong Peng and Yuezhong Xian
Dalton Transactions 2015 - vol. 44(Issue 10) pp:NaN4629-4629
Publication Date(Web):2015/01/28
DOI:10.1039/C4DT03883E
In this work, we developed a novel, label-free, colorimetric sensor for Pb2+ detection based on the acceleration of gold leaching by graphene oxide (GO) at room temperature. Gold nanoparticles (AuNPs) can be dissolved in a thiosulfate (S2O32−) aqueous environment in the presence of oxygen; however, the leaching rate is very slow due to the high activation energy (27.99 kJ mol−1). In order to enhance the reaction rate, some accelerators should be added. In comparison with the traditional accelerators (metal ions or middle ligands), we found that GO could efficiently accelerate the gold leaching reaction. Kinetic data demonstrate that the dissolution rate of gold in the Pb2+–S2O32−–GO system is 5 times faster than that without GO at room temperature. In addition, the effects of surface modification and the nanoparticle size on the etching of AuNPs were investigated. Based on the GO-accelerated concentration-dependent colour changes of AuNPs, a colorimetric sensor for Pb2+ detection was developed with a linear range from 0.1 to 20 μM and the limit of detection (LOD) was evaluated to be 0.05 μM. This colorimetric assay is simple, low-cost, label-free, and has numerous potential applications in the field of environmental chemistry.
Co-reporter:Yuan Tian, Siqiu Ye, Qin Ran, Yuezhong Xian, Jingjing Xu, Ru Peng and Litong Jin
Physical Chemistry Chemical Physics 2010 - vol. 12(Issue 40) pp:NaN13295-13295
Publication Date(Web):2010/09/09
DOI:10.1039/C001205J
In this paper, catechol, 1,4-dihydroxybenzene and dopamine are investigated as precursors of electrophiles for Michael addition reaction with the self-assembled monolayer (SAM) of 4-thiouracil (4-TU) via electrochemical triggering. All compounds can undergo Michael addition reaction with 4-TU; however, only catechol can react with 4-TU with high efficiency. The catechol-terminated SAMs, via electrochemically triggered Michael addition reaction, exhibit reversible redox response. In addition, we find that catechol-terminated SAMs can complex with Ni2+ and Cu2+ with different electrochemical behaviors. Moreover, the mechanism of complexation of Ni2+and Cu2+ with catechol-terminated SAMs is also demonstrated with electrochemical and spectrometric methods. Based on the different electrochemical behaviors of Cu2+ and Ni2+ complex, the catechol-terminated SAMs provide a potential platform for metal ions recognition.
Co-reporter:Wenjing Zhang, Yixuan Zhang, Xinhao Shi, Cong Liang and Yuezhong Xian
Journal of Materials Chemistry A 2011 - vol. 21(Issue 40) pp:NaN16183-16183
Publication Date(Web):2011/09/13
DOI:10.1039/C1JM12353J
The paper reports on covalent clicking of rhodamine-B (RhB) bearing a terminal azide group to alkyne-terminated silica coated superparamagnetic iron oxide nanoparticlesvia the copper(I)-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction. The course of the reaction was followed the use of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, fluoroscopy, and magnetics. The RhB labelled Fe3O4@SiO2 nanoparticles exhibit stable fluorescence and no detectable leakage of the fluorescent dye because the resulting 1,4-disubstituted 1,2,3-triazole ring formed via click reaction is thermally stable and relatively inert to hydrolysis, oxidation, and reduction. Due to the superparamagnetic property of the Fe3O4 and the RhB molecule covalently decorated in the Fe3O4@SiO2 framework, the nanoparticles are endowed with properties of a contrast agent in magnetic resonance imaging (MRI) and optical imaging modality. The cytotoxicity tests indicate the bifunctional nanoparticles could be applied in biomedical or bioengineering field.
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