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。     

纳米金/碳纳米管复合材料修饰电极催化鲁米诺电致发光体系的研究

制备了纳米金/多壁碳纳米管(MWNT)复合材料修饰电极,并将此电极应用于鲁米诺电化学发光体系.电化学发光实验表明,此复合材料修饰电极同时具备了纳米金和碳纳米管的催化性能.此外通过电极活性表面积测算、电化学交流阻抗实验等方法研究了纳米金和碳纳米管在此体系催化过程中的作用.纳米金/碳纳米管修饰电极具有良好的重现性,可以广泛应用于鲁米诺电化学发光测定体系.     

介孔炭/纳米金修饰玻碳电极的制备及其应用研究

制备了介孔炭/纳米金修饰玻碳电极,并对对苯二酚(HQ)在该修饰电极上的电化学行为进行了研究。与HQ在纯介孔炭材料修饰玻碳电极上的电化学响应相比,HQ在该修饰电极上的氧化峰和还原峰电流均大大增加,表明纳米金与介孔炭复合后对HQ具有良好的催化作用。HQ在该修饰电极上经过富集后,峰电流明显增大。采用循环伏安法对HQ电化学行为进行研究,结果表明,HQ在3.0×10-8~1.0×10-6mol/L和1.0×10-6~1.0×10-4mol/L浓度范围内与峰电流呈良好的线性关系,据此建立了检测HQ的电化学分析方法。该方法的相对标准偏差为0.69%,检出限(S/N=3)为1.0×10-8mol/L,具有较高的稳定性和灵敏度。     

Fabrication of Bismuth/Multi-walled Carbon Nanotube Composite Modified Glassy Carbon Electrode for Determination of Cobalt

A bismuth/multi‐walled carbon nanotube (Bi/MWNT) composite modified electrode for determination of cobalt by differential pulse adsorptive cathodic stripping voltammetry is described. The electrode is fabricated by potentiostatic pre‐plating bismuth film on an MWNT modified glassy carbon (GC) electrode. The Bi/MWNT composite modified electrode exhibits enhanced sensitivity for cobalt detection as compared with the bare GC, MWNT modified and bismuth film electrodes. Numerous key experimental parameters have been examined for optimum analytical performance of the proposed electrode. With an adsorptive accumulation of the Co(II)‐dimethylglyoxime complex at ?0.8 V for 200 s, the reduction peak current is proportional to the concentration of cobalt in the range of 4.0×10^?10?1.0×10^?7 mol/L with a lower detection limit of 8.1×10^?11 mol/L. The proposed method has been applied successfully to cobalt determination in seawater and lake water samples.     

生物合成纳米金与MWCNTs/L-Cys复合修饰玻碳电极测定左旋多巴

利用荷叶萃取液生物合成纳米金,并与多壁碳纳米管/L-半胱氨酸复合成修饰电极材料,研究了左旋多巴在该修饰电极上的电化学行为.在0.2 mol/L乙酸-乙酸钠体系(pH=2.6)中,氧化峰电流与左旋多巴浓度在0.6~40μmol/L及60~120μmol/L范围内呈良好的线性关系,检出限达5.2×10-8mol/L.实验结果表明,生物合成纳米金复合多壁碳纳米管/L-半胱氨酸修饰电极具有良好的稳定性和高灵敏度,对实际样品测定的回收率在91.2%~102.5%之间.     

聚多巴胺/多壁碳纳米管/玻璃碳电极上多巴胺的电分析

基于多巴胺（DA）在多壁碳纳米管（MWCNTs）修饰玻璃碳（GC）电极上的电聚合,制得聚多巴胺(PDA)/MWCNTs/GC电极,并对该修饰电极进行了电化学阻抗谱 (EIS)和循环伏安法(CV)表征。 在该修饰电极上,DA呈现良好的电化学行为。在pH=7.4磷酸缓冲溶液中其氧化电流显著高于在裸电极上的响应,且能有效地抑制2.0 mmol/L抗坏血酸(AA)或K4Fe(CN)6的直接电化学响应,表明MWCNTs可增敏信号,且阳离子选择透过性PDA膜可抑制阴离子的电化学干扰。 采用CV实验检测DA,DA氧化的半微分伏安峰高(ipa-sd)与多巴胺浓度在0.08～1.76 μmol/L范围内呈线性关系,在无抗坏血酸和有0.5 mmol/L抗坏血酸共存时的线性回归方程分别为ipa-sd(μA/s1/2)=0.107+0.405c(μmol/L)（r2=0.986）和ipa-sd(μA/s1/2)=0.628+0.649c(μmol/L)(r2=0.992),检测限均为8.0×10-8 mol/L(S/N=3)。 该法用于盐酸多巴胺注射液中多巴胺的快速测定,结果满意。     

金纳米粒子/碳纳米管修饰电极对4 壬基酚的电催化氧化及检测研究

制备了金纳米粒子/碳纳米管修饰玻碳电极(AuNPs-CNTs/GCE),采用循环伏安法和线性扫描伏安法研究了4-壬基酚在修饰电极上的电化学行为,并建立了一种灵敏简便地检测4-壬基酚的电化学方法。优化了pH值、扫描速率、富集时间等测定参数,并计算出pH值与氧化峰电压、扫描速率与氧化峰电流之间的数量关系。在pH 10.0的BR缓冲溶液中,4-壬基酚在AuNPs-CNTs/GCE上出现灵敏的氧化峰,氧化电位为0.51 V。与裸玻碳电极(GCE)和单一碳纳米管修饰电极(CNTs/GCE)相比,AuNPs-CNTs/GCE明显提高了4-壬基酚的氧化电流。在优化实验条件下,4-壬基酚的浓度分别在0.05～4μmol/L和6～14μmol/L范围内与氧化峰电流呈良好的线性关系,检出限为0.023μmol/L,对于实际样品测定的回收率为95%～104%。该修饰电极具有良好的重现性和稳定性,可用于环境样品中4-壬基酚的直接检测。     

Sensitive Voltammetric Determination of Captopril Using a Carbon Paste Electrode Modified with Nano-TiO2/Ferrocene Carboxylic Acid

A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix.The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods.The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values.Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV.The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques.A calibration curve in the range of 0.03 to 2400μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3σ) under the optimized conditions.The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.     

Voltammetric Determination of Neotame by Using Chitosan/Nickelnanoparticles/Multi Walled Carbon Nanotubes Biocomposite as a Modifier

A selective and simple biosensor was prepared by immobilizing chitosan/nickelnanoparticles/multi-walled carbon nanotubes biocomposite on the glassy carbon electrode surface for voltammetric quantification of neotame. The properties and morphology of the modified electrode surfaces were characterized by scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX). Electro oxidation of neotame on this modified surface was examined through cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. The biocomposite modified surface (Chi/NiNPs/MWCNTs/GCE) proposed in this study showed good electrocatalytic activity for neotame with an improved voltammetric peak current at 1.004 V, unlike the bare glassy carbon electrode (GCE) surface and several other modified surfaces. Under optimum conditions, Chi/NiNPs/MWCNTs/GCE gave linear SWV responses at the range of 2 μM ∼50 μM for neotame with 0.84 μM determination limit. This voltammetric sensor was successfully employed for the quantification of neotame on food samples and showed long-term stability, advanced voltammetric behavior, and good repeatability. Selective, accurate, and precise determination of neotame highlight the importance of this electrode in monitoring the control of food additives and ensures attract a great deal of attention.     

氧化石墨烯/铁氰化铈修饰玻碳电极同时测定扑热息痛和咖啡因

采用滴涂法和电沉积法制备了氧化石墨烯/铁氰化铈(CeFe(CN)6)纳米复合膜修饰玻碳电极。用扫描电镜对氧化石墨烯和氧化石墨烯/CeFe(CN)6纳米复合膜进行了表征。分别用循环伏安法和差分脉冲伏安法研究了扑热息痛和咖啡因在修饰电极上的电化学行为。结果表明,在0.1 mol/L醋酸盐缓冲溶液(pH5.0)中,扑热息痛和咖啡因在此修饰电极上具有良好的电化学行为,扑热息痛和咖啡因分别在1.0×10-7～6.0×10-5mol/L和1.0×10-6～1.3×10-4mol/L浓度范围内与电化学响应信号呈良好的线性关系,相关系数分别为0.990和0.992;信噪比为3时,扑热息痛和咖啡因检出限分别为5.0×10-8mol/L和5.2×10-7mol/L。将本方法用于人尿样品分析,回收率为96.1%～105.4%。     

A Selective Simultaneous Determination of Levodopa and Serotonin Using a Glassy Carbon Electrode Modified with Multiwalled Carbon Nanotube/Chitosan Composite

A glassy carbon electrode (GCE) modified with carbon nanotube/chitosan (MWCNTs‐CHT/GCE) was used for the sensitive voltammetric determination of levodopa (Lev) and serotonin (Ser). The measurements were carried out using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA). Under the optimum conditions the electrode provides a linear response versus Lev and Ser concentrations in the range of 2.0–220.0 µM and 0.5–130.0 µM, respectively, using DPV. The modified electrode was satisfactorily used for determination of Lev and Ser in human serum and urine with satisfactory results.     

氧等离子体改性的聚苯胺/碳纳米管电化学性能

由乳液聚合法制备聚苯胺/碳纳米管复合电极材料,再利用感应耦合氧等离子体源对其进行射频放电处理,制得改性后的复合材料,进一步研究氧等离子体处理时间对材料表面性质和电化学性能的影响。通过SEM和FTIR对复合材料的表面形貌和组成进行分析和表征,结果显示复合材料在改性后的微观形貌均一,粒径变小且颗粒间团聚减轻,材料表面引入了羟基官能团。电化学测试表明,经氧等离子体改性处理10 min后,聚苯胺/碳纳米管复合材料具有突出的电化学特性,比电容为287.8 F.g-1,为改性前的1.7倍,同时等效串联电阻(ESR)降低了67.7%,是一种优良的超级电容器电极材料。由此也表明氧等离子体改性是一种高效的电极材料改性方法。     

维生素B6在维生素B12修饰电极上的电化学行为及其分析应用

采用循环伏安法研究了维生素B6在维生素B12修饰玻碳电极上的电化学行为,建立了测定痕量维生素B6的新方法.在pH 8.6的NH3-NH4Cl缓冲溶液中,维生素B6在修饰电极上产生一个灵敏的氧化峰,采用差分脉冲伏安法测定,其氧化峰电流与维生素B6的浓度在8.0×10-7～2.0×10-4 mol/L范围内呈良好的线性关系,检出限为2.0×10-7 mol/L.该修饰电极具有良好的选择性、灵敏度及稳定性,用于片剂中维生素B6的定量分析,结果令人满意.     

Preparation of Carbon Nanotubes/Neutral Red Composite Film Modified Electrode and Its Catalysis on Rutin

Neutral red was directly electropolymerized onto the carbon nanotubes modified electrode. A polymerized neutral red/carbon nanotubes composite film was characterized by scanning electron micrograph (SEM) and cyclic voltammetry (CV). Well‐defined voltammetric responses are observed for [Fe(CN)₆]^4?/3? on the composite film modified glassy carbon electrode. And it's found that this modified electrode has good catalysis on the redox of rutin. Differential pulse voltammetry method was used to determinate the concentration of rutin and obtain a linear equation between the current and concentration in a certain range. The modified electrode is satisfied with us for its good sensibility and stability.     

基于Nafion/碳纳米粒子修饰的葡萄糖传感器

采用滴涂法制备了Nafion/碳纳米粒子复合物修饰玻碳电极,该电极对H2O2具有良好的电催化氧化性能。还利用滴涂法制备了Nafion/碳纳米粒子复合物包裹的葡萄糖酶电化学生物传感器,该生物传感器对葡萄糖有着良好的电催化作用。应用该传感器对葡萄糖进行了检测,检测线性范围为2.0×10-6～6.0×10-3mol/L,检出限为1.6×10-6mol/L(S/N=3),实验结果表明该传感器具有良好的稳定性、重现性和抗干扰能力。对小鼠血清样品中的葡萄糖进行检测,结果令人满意。     

基于金纳米粒子/聚阿魏酸/多壁碳纳米管修饰电极的DNA计时库仑法生物传感器的制备

构建了基于金纳米粒子/聚阿魏酸/多壁碳纳米管(AuNPs/PFA/MWCNTs)修饰电极的DNA计时库仑法生物传感器.利用循环伏安技术在多壁碳管修饰的玻碳电极表面上聚合一层阿魏酸,在恒电位条件下,在阿魏酸表面沉积金纳米粒子,巯基DNA作为探针通过金硫键固定在金纳米粒子表面.电化学交流阻抗技术(EIS)与扫描电镜(SEM...     

碳纳米管负载纳米铂修饰电极及电催化氧化H2O2的研究

采用化学气相沉积法在碳纳米管(CNT)上负载Pt纳米颗粒,并制备了CNT-Pt修饰玻碳电极(CNT-Pt/GCE).研究了该修饰电极在磷酸缓冲液中对H2O2的电催化氧化作用以及实验条件的影响.计算了H2O2在CNT-Pt/GCE上的电极反应速率常数.结果表明,CNT-Pt/GCE对H2O2的电化学氧化具有良好的催化作用,电极反应速率常数比铂电极高约2.65倍.初步探讨了电催化氧化机理,为酶电化学传感器的研制提供了一条新的途径.     

CuNPs/PAA/GR纳米新材料修饰玻碳电极检测猪肉中的莱克多巴胺

采用一种温和且简单的原位生长法将铜纳米粒子和石墨烯非共价键合,形成一种对莱克多巴胺催化活性高的复合纳米新材料Cu NPs/PAA/GR。该材料用扫描电镜表征形貌,用阻抗表征修饰电极。不同扫速和p H值条件下,以其修饰玻碳电极构建的电化学体系受吸附控制,莱克多巴胺在该电极表面的反应机理属两电子转移过程。体系中电化学参数为:电子转移数(n)=1.7,修饰电极的有效面积为3.57 cm2,为裸电极的12.6倍,电极吸附量(Гs)为1.98×10-12mol/cm2。采用微分脉冲伏安法进行检测,莱克多巴胺的浓度在1~30μmol/L范围内呈良好线性关系(r2=0.990 2),检出限(S/N=3)为18.3 nmol/L。该传感器经济易制备、灵敏性高、稳定性与重现性好。将该传感器用于猪肉中莱克多巴胺的检测,其回收率为97.0%~102.5%,相对标准偏差为2.8%~3.2%。     

多臂碳纳米管/Nafion复合材料修饰玻碳电极测定痕量的铅离子

A composite material of nitric acid oxidized multiwalled carbon nanotube （MWNT） and Nation was prepared. Such composite was modified on a glassy carbon electrode to determine trace of lead by differential pulsed voltammetry. In pH=6.47 NaNO3 solution, Pb^2＋ ions were accumulated on the modified electrode at -0.4 V. Compared with a bare and a Nation film coated electrode, the composite coated GC electrode can reduce the accumulating potential and eliminate the toxic character of mercury. The calibration plots were linear at low concentration of 5.0× 10^-9-2.0× 10^-8 mol/L and high concentration of 2.5× 10^-8-5.0× 10^-6 mol/L. The performances characteristics indicate that the electrode can be used to determine trace Pb^2＋ ions.     

聚赖氨酸/多壁碳纳米管修饰电极测定大米中的铅

通过滴涂及电聚合方式分别将多壁碳纳米管和赖氨酸共修饰于玻碳电极上,制备出聚赖氨酸/多壁碳纳米管修饰电极,并建立了阳极溶出伏安法测定铅离子的新方法。采用线性扫描伏安法及循环伏安法研究了铅离子在修饰电极上的电化学行为,并考察了测定底液、底液p H值、富集电位、富集时间等条件的影响。在最佳实验条件下,铅离子的溶出峰电流与其浓度在2.0×10-7~8.0×10-5mol·L-1范围内呈良好的线性关系,检出限为1.0×10-7mol·L-1。利用所制备的修饰电极对大米样品进行加标回收实验,回收率为98%~102%。该方法具有良好的灵敏度和稳定性,已成功应用于大米样品中铅离子的测定。