铂微粒弥散的聚2，5－二甲氧基苯胺膜电极在甲醇电氧化中的催化行为

研究了电化学方法制备的铂微粒弥散的聚２，５－二甲氧基苯胺膜电极对甲醇电氧化的催化行为以及影响催化活性的主要因素。以ＸＰＳ、ＳＥＭ表征了这种电极材料的表面结构，结果表明，在酸性介质中，该膜电极对甲醇电氧化有高的催化活性和稳定性。     

Gold nanoparticle-modified glassy carbon electrode for electrochemical investigation of aliphatic di-carboxylic acids in aqueous media

The electrochemical reduction of di-carboxylic acids; oxalic, succinic, malic, and tartaric have been studied on the gold nanoparticles modified electrode in aqueous media solution of 0.1 M KCl. Gold nanoparticle (Au_NPs)-modified electrodes were prepared by the electrodeposition with cyclic voltammetric method onto glassy carbon electrode in acidic media. The surface morphology of the electrodeposited gold nanoparticles was examined by SEM. Also, the electrochemical properties of the prepared electrodes were investigated with different electrochemical techniques; cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Cyclic voltammetric, chronoamperometric, and electrochemical impedance spectroscopic techniques were used for investigating the electrochemical behavior of the particulate acids. The modification of the electrode with Au nanoparticles (Au_NPs) enables the appearance of cyclic voltammogram peaks completely clear and sharp for the acids under investigation in comparison with the poor behavior of them in absence of the modification. All acids undergo totally irreversible redox reaction in neutral and acid media. The cyclic voltammetric response of the investigated acids is sensitive to pH, as well as of the scan rate. Each acid has a different reduction peak position from the other acids depending on the structure of the acid undergo the electroreduction process. Further, the lowest unoccupied molecular orbital energies of the investigated acids have been theoretically evaluated and are compared with their electroreduction potential peaks.     

Assembly process of CuHCF/MPA multilayers on gold nanoparticles modified electrode and characterization by electrochemical SPR

Gold nanoparticles were deposited onto 2-mercaptoethylamine (MEA)-assembled planar gold thin film to construct gold nanoparticles modified electrode by virtue of a solution-based self-assembly strategy. Subsequently, 3-mercaptopropionic acid (MPA)-bridged copper hexacyanoferrate (CuHCF) multilayers were constructed on the as-prepared gold nanoparticles modified electrode. The resulted multilayer nanostructures were investigated by electrochemical surface plasmon resonance (EC-SPR) and atomic force microscopy (AFM) with primary emphasis upon the effect of the gold nanoparticles on the MPA/CuHCF multilayers growth and their surface morphology. Compared with the multilayer system on a planar gold electrode, the different electrochemical and optical properties might result from higher curvature effect and extraordinary surface-to-volume ratio characteristic of gold nanoparticles and the nanoparticle-selective growth of CuHCF. A dendrimer-like assembly process was proposed to explain the experiment results. This new motif of multilayer on the gold nanoparticles modified electrode was different from that of on a planar gold electrode, indicating a potential application of EC-SPR technique in the study of nanocomposite materials.     

抗坏血酸在铂纳米粒子/碳纳米管/聚吡咯复合修饰电极上的电化学行为

研究了抗坏血酸在铂纳米粒子/碳纳米管/聚吡咯复合膜修饰电极上的电化学行为,发现复合修饰电极对抗坏血酸的电化学反应具有较好的电催化作用,与空白电极相比电化学氧化电流增加了7倍。用电化学阻抗谱研究了电子在修饰电极界面上的传输过程,发现修饰电极的电催化性能与修饰电极可以提高界面电子传输能力是相关的。同时研究了碳纳米管用量、支持电解质、扫速、电沉积条件等因素对抗坏血酸在修饰电极上电化学行为的影响。     

Nonenzymatic glucose detection by using a three-dimensionally ordered, macroporous platinum template

A three-dimensionally ordered, macroporous, inverse-opal platinum film was synthesized electrochemically by the inverted colloidal-crystal template technique. The inverse-opal film that contains platinum nanoparticles showed improved electrocatalytic activity toward glucose oxidation with respect to the directly deposited platinum; this improvement is due to the interconnected porous structure and the greatly enhanced effective surface area. In addition, the inverse-opal Pt-film electrode responds more sensitively to glucose than to common interfering species of ascorbic acid, uric acid, and p-acetamidophenol due to their different electrochemical reaction mechanisms. Results showed that the ordered macroporous materials with enhanced selectivity and sensitivity are promising for fabrication of nonenzymatic glucose biosensors.     

Electroreduction of Oxygen and Electrooxidation of Methanol at Carbon and Single Wall Carbon Nanotube Supported Platinum Electrodes

The present research aimed at investigating the electrocatalytic properties and the electrochemical deposition of Pt nanoparticles on carbon powder, carbon nanotube and preparation of carbon and single wall carbon nanotube supported platinum electrodes. The Pt nanoparticles were synthesized by electroreduction of hexachloroplatinic acid in aqueous solution at ?200 mV. Electrocatalytic properties of the modified electrodes for oxygen reduction were investigated by cyclic voltammetry in O₂ saturated solution containing 0.1 M HClO₄. Methanol electrooxidation at the modified surfaces in 0.5 M HCLO₄ was studied by cyclic voltammetry. The corresponding results showed that the Pt/SWCNT/GC electrode exhibits more improved catalytical activity than the Pt/C/GC electrode.     

电极/反相微乳液体系电沉积制备纳米金镀层

将含有氯化金的强酸性水溶液作为水相与Triton X-100、正己醇、正己烷组成反相微乳液体系, 并以该微乳液构成电极/反相微乳液电极系统, 利用电沉积方法成功地制备出纳米Au镀层. 循环伏安和交流阻抗对反相微乳液体系电沉积过程的研究发现, 微乳液中Au(III)的还原为完全不可逆过程, 其电化学反应的阻抗值约为具有相同表观浓度氯化金水溶液体系的5.5倍. SEM研究结果表明, 利用微乳液体系电沉积获得的金镀层由纳米Au颗粒组成, 直径为50 nm左右. 所制备的纳米Au修饰电极由于具有较大的比表面积, 其电化学性能优于纯Au电极, 该电极在酸性条件下有较好的析氢性能, 在碱性条件对丙三醇有较好的电催化氧化性能.     

Construction of dsDNA biosensor based on dendritic SiO2 nanoparticle and investigation on its interaction with benzo[a]pyrene

In this work, a new dsDNA biosensor was constructed to monitor the interaction of DNA and benzo[a]pyrene (BaP). Firstly, dendritic SiO₂ nanoparticles were synthesized by silanization of SiO₂ nanoparticles with (??-(methacryloyloxy)propyl) trimethoxysilane and polymerization with acrylic acid. Then, due to the rich carboxyl groups of these nanoparticles, they were associated with the amino groups of a self-assembly membrane formed on the gold electrode by a sulfur-containing compound, 5-amino-3-mercapto-1,2,4-triazole. Finally, dsDNA was immobilized on the electrode surface by static adsorption with the aid of metallic ion. The whole immobilization steps were characterized by cyclic voltammogram and electrochemical impedance spectrum. After that, using methylene blue as a probe, the interaction of BaP with dsDNA was investigated. A linear relationship between the percentages of current decrease with the logarithm of BaP concentrations was found in the range from 0.33 to 133???M.     

Glassy carbon electrode modified with gold nanoparticles and DNA for the simultaneous determination of uric acid and norepinephrine under coexistence of ascorbic acid.

A novel biochemical sensor was assembled on a glass carbon electrode by a electrodeposition process. Gold nanoparticles were deposited by potential +1.5 V on the glass carbon electrode. CT-DNA was deposited by potential +1.5 V on the gold nanoparticles array electrode. The properties of the modified electrode were characterized by electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Our results showed that gold nanoparticles increase the DNA membrane capacitance and reduce the membrane resistance. This modified electrode can selectively determine uric acid and norepinephrine in the presence of a larger amount of ascorbic acid. The fabricated electrode showed good sensitivity, reproducibility, and stability.     

Application of Carbon Paste Electrode Modified with Carbon Nanofibres/Polyaniline/Platinum Nanoparticles as an Electrochemical Sensor for the Determination of Bezafibrate

The present study deals with the development of an electrochemical sensor for quantitative determination of Bezafibrate (BZF) based on carbon nanofibers/polyaniline/platinum nanoparticles modified carbon paste electrode (CNF/PANI/Pt/CPE). BZF is a fibric acid derivative and is used largely in the treatment of lipid disorders. The nanocomposite was synthesized by in situ polymerization of aniline using ammonium persulphate and platinum nanoparticles were uniformly decorated on the CNF/PANI surface by reducing hexachloroplatinic acid using sodium borohydride. The electrochemical response of BZF at CNF/PANI/Pt/CPE was studied using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The above study resulted into significant improvement of the electrochemical signal towards the oxidation of BZF, revealing that the oxidation process is highly favorable at the surface of modified electrode. The anodic peak current I_p (μA) is found to be linearly dependent on BZF concentration in the range of 0.025 μM to 100 μM with a detection limit of 2.46 nM. The practical analytical utilities of the sensor were investigated by performing the experiments on synthetic pharmaceutical formulations, human blood serum and urine samples which offered good recovery, suggesting the high efficacy and authenticity of CNF/PANI/Pt/CPE sensor for BZF determination.     

Rhombic Polyaniline Microsheets Constituted of Nanoparticles:Synthesis and Application to the Detection of Dopamine

Rhombic polyaniline microsheets constituted of nanoparticles with the average diameter of 130 nm were synthesized and characterized by SEM, XRD and FTIR spectroscopy. A glassy carbon electrode modified with such rhombic polyaniline microsheets was fabricated and employed to detect dopamine via cyclic voltammetry, which displayed excellent electrochemical stability and sensitivity compared with the bare electrode. A linear relationship between the concentrations of dopamine and its oxidation peak currents was obtained. The proposed method was simple and economical in terms of the electrochemical method and apparatus.     

Interfacial synthesis and characterization of camphor sulfonic acid doped poly(aniline-co-2,5-dimethoxyaniline)

Polyaniline doped with camphor sulfonic acid, poly(2,5-dimethoxyaniline) and their copolymers were synthesized by interfacial method. The FT-IR spectra, UV-Vis absorption spectra and X-ray diffraction patterns were used to characterize the molecular structures of the polymers. The morphology of the polymers was studied by using SEM and TEM. Voltammetric study was done to investigate the electrochemical behavior of these polymers. The results show that the polymers were in microscale with the different shapes such as rod, flake and sphere, respectively. All the homopolymers and copolymers had a poor crystallinity. The conductivity of the copolymers of aniline with 2,5-dimethoxyaniline decreased with increase of 2,5-dimethoxy-aniline molar content.     

单分散PtNi纳米粒子特殊的红外光学性能(英文)

采用电位置换反应以及化学还原法制备了单分散PtNi纳米粒子,循环伏安结果显示该纳米粒子在0.1mol·L-1硫酸介质中对CO的氧化表现出比本体Pt电极更好的电催化活性.以CO为探针分子,采用电化学原位红外光谱研究了PtNi纳米粒子上的特殊红外光学性能.结果表明,PtNi纳米粒子无论是在玻碳电极还是在金电极上,均表现出对称的双极谱峰,同时给出很强的增强效应.论文研究结果有助于进一步了解低维纳米材料特殊红外性能的本质.     

基于杂环羧酸配体的金属有机骨架化合物合成、表征及性质研究

以噻吩-2,5-二羧酸为主要配体,借助第二配体----4,4-联吡啶或者邻菲罗啉通过水热法合成了三种MOFs材料,分别是[Cd (tdc) (bpy)]n、[Zn (tdc) (bpy)]n、[Co (tdc) (phen)]n。利用X射线单晶衍射仪、红外光谱仪对三种MOFs材料进行了结构表征与分析,同时利用荧光光谱仪、热重分析仪和电化学工作站测定了三种MOFs材料的荧光性质、热稳定性和MOFs材料修饰玻碳电极的电化学行为,结果表明,三种MOFs材料比配体更好的荧光强度和热稳定性,制备的[Co (tdc) (phen)]n修饰玻碳电极,对铁氰化钾溶液和含1.0mmol/L NaNO2的pH = 5 PBS溶液,均比裸玻碳电极表现出更强的循环伏安响应,有望作为修饰剂应用于修饰玻碳电极中。     

Gold nanoparticles on a thiol-functionalized silica network for ascorbic acid electrochemical detection in presence of dopamine and uric acid

A simple preparation methodology able to stabilize gold nanoparticles and to obtain an electrode which detects ascorbic acid, uric acid, and dopamine by different techniques is presented. A 3-mercaptopropyl-functionalized silica network was synthesized using the sol–gel method. Gold nanoparticles (nAu) were immobilized on the material at synthesis by adding a sol of these previously prepared particles to the reaction mixture. The electrochemical behavior of the SiO₂/MPTS/Au carbon paste electrode was studied using cyclic voltammetry in the presence of a hexacyanoferrate probe molecule. The presence of nAu in the functionalized silica network changes the electrochemical characteristics of the material, favoring the electron transfer process of this complex ion. The SiO₂/MPTS/Au electrode was proven to be an efficient tool in the simultaneous determination of ascorbic acid (H₂AA), dopamine (DA), and uric acid (UA) using square wave voltammetry techniques. With the nAu on the electrode, an increase in the peak current related to the redox process of the H₂AA, DA, and UA was observed. The separations of the anodic peak potentials between DA/H₂AA and UA/H₂AA were 310 and 442?mV, respectively. The results obtained show that the SiO₂/MPTS/Au electrode can be used in the simultaneous determination of H₂AA, DA, and UA.     

Voltammetric Determination of Metol on a Gold Nanoparticle Modified Carbon Molecular Wire Electrode

A carbon molecular wire electrode was fabricated using diphenylacetylene as the modifier and gold nanoparticles were electrodeposited on the surface. The morphology and electrochemical properties of this modified electrode were investigated by scanning electron microscopy and electrochemical impedance spectroscopy. Two well-defined peaks for metol appeared using this gold nanoparticle-modified carbon molecular wire electrode by cyclic voltammetry with a high current response. These results demonstrate a synergistic effect between the gold nanoparticles and the carbon molecular wire electrode resulting in a rapid electrochemical reaction. The electrochemical conditions for metol were optimized on the modified electrode and a detection limit of 0.64?µmol/L and a linear dynamic range between 2.0 to 800.0?µmol/L were obtained. This modified electrode provided good selectivity, high sensitivity, and acceptable reproducibility, demonstrating promise for the determination of metol in the water.     

Amperometric biosensor based on thermally activated polymer-stabilized metal nanoparticles

Polymer-stabilized Pd nanoparticles on carbon support were synthesized by a low thermal procedure that does not involve the utilization of a reducing agent such as NaBH₄ or hydrogen gas for the formation of the metallic nanoparticles. The Pd-catalyzed graphite particles were then mixed with known amounts of glucose oxidase (GOx) enzyme and Nafion to prepare a GOx-immobilized ink. A glassy carbon electrode (GCE) modified with the GOx ink was used to evaluate the performance of the biosensor electrode. The results of TEM and AFM show that the Pd nanoparticles are uniformly distributed on top of the substrate. Results are presented for sensing glucose through the voltammetric measurement of H₂O₂. Coupled with the simplicity of preparation, the biosensor exhibited high sensitivity and extended linear range for glucose measurement. Further, the electrochemical characteristics of the nanocomposite biosensor were evaluated with respect to the electrochemistry of potassium ferricyanide by cyclic voltammetry. Whereas the presence of polymer and Nafion improved the stability of both the ink and biosensor electrode, the concentration of glucose was measured without interferences from oxygen, ascorbic acid and uric acid because of the Nafion.     

基于多边形金纳米颗粒的非标记型可卡因适体传感器的研制

实验合成了多边形金纳米颗粒,通过壳聚糖(CHIT)将合成的多边形金纳米颗粒固定在玻碳电极表面,然后通过自组装技术将带巯基的捕获DNA探针固定在修饰有多边形金纳米颗粒的电极表面,利用杂交反应使可卡因适体与DNA捕获探针结合,制成非标记型可卡因适体传感器。以六氨合钌作为电化学指示剂,通过测量传感器与目标物可卡因结合前后电流变化情况对可卡因进行测定。考察了缓冲溶液的pH、可卡因培育时间、扫描速度等对测定的影响。结果表明,在pH为7.40时该传感器的检测范围为1.0×10-10～1.0×10-3 mol/L,检测限为3.0×10-11 mol/L。该传感器制作简单,响应好,抗干扰能力强。     

One-step synthesis of Pt nanoparticles/reduced graphene oxide composite with enhanced electrochemical catalytic activity

A one-step electrochemical approach for synthesis of Pt nanoparticles/reduced graphene oxide(Pt/RGO) was demonstrated.Graphene oxide(GO) and chloroplatinic acid were reduced to RGO and Pt nanoparticles(Pt NPs) simultaneously,and Pt/RGO composite was deposited on the fluorine doped SnO 2 glass during the electrochemical reduction.The Pt/RGO composite was characterized by field emission-scanning electron microscopy,Raman spectroscopy and X-ray photoelectron spectroscopy,which confirmed the reduction of GO and chloroplatinic acid and the formation of Pt/RGO composite.In comparison with Pt NPs and RGO electrodes obtained by the same method,results of cyclic voltammetry and electrochemical impedance spectroscopy measurements showed that the composite electrode had higher catalytic activity and charge transfer rate.In addition,the composite electrode had proved to have better performance in DSSCs than the Pt NPs electrode,which showed the potential application in energy conversion.     

单分散PtNi纳米粒子特殊的红外光学性能

采用电位置换反应以及化学还原法制备了单分散PtNi 纳米粒子,循环伏安结果显示该纳米粒子在0.1mol·L^-1硫酸介质中对CO的氧化表现出比本体Pt 电极更好的电催化活性. 以CO为探针分子,采用电化学原位红外光谱研究了PtNi 纳米粒子上的特殊红外光学性能. 结果表明,PtNi 纳米粒子无论是在玻碳电极还是在金电极上,均表现出对称的双极谱峰,同时给出很强的增强效应. 论文研究结果有助于进一步了解低维纳米材料特殊红外性能的本质.