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《Electroanalysis》2005,17(24):2217-2223
Glassy carbon electrode modified by microcrystals of fullerene‐C60 mediates the voltammetric determination of uric acid (UA) in the presence of ascorbic acid (AA). Interference of AA was overcome owing to the ability of pretreated fullerene‐C60‐modified glassy carbon electrode. Based on its strong catalytic function towards the oxidation of UA and AA, the overlapping voltammetric response of uric acid and ascorbic acid is resolved into two well‐defined voltammetric peaks with lowered oxidation potential and enhanced oxidation currents under conditions of both linear sweep voltammetry (LSV) and Osteryoung square‐wave voltammetry (OSWV). At pH 7.2, a linear calibration graph is obtained for UA in linear sweep voltammetry over the range from 0.5 μM to 700 μM with a correlation coefficient of 0.9904 and a sensitivity of 0.0215 μA μM?1 . The detection limit (3σ) is 0.2 μM for standard solution. AA in less than four fold excess does not interfere. The sensitivity and detection limit in OSWV were found as 0.0255 μA μM?1 and 0.12 μM, for standard solution respectively. The presence of physiologically common interferents (i.e. adenine, hypoxanthine and xanthine) negligibly affects the response of UA. The fullerene‐C60‐modified electrode exhibited a stable, selective and sensitive response to uric acid in the presence of interferents. 相似文献
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In this paper, a silver doped poly(L ‐valine) (Ag‐PLV) modified glassy carbon electrode (GCE) was fabricated through electrochemical immobilization and was used to electrochemically detect uric acid (UA), dopamine (DA) and ascorbic acid (AA) by linear sweep voltammetry. In pH 4.0 PBS, at a scan rate of 100 mV/s, the modified electrode gave three separated oxidation peaks at 591 mV, 399 mV and 161 mV for UA, DA and AA, respectively. The peak potential differences were 238 mV and 192 mV. The electrochemical behaviors of them at the modified electrode were explored in detail with cyclic voltammetry. Under the optimum conditions, the linear ranges were 3.0×10?7 to 1.0×10?5 M for UA, 5.0×10?7 to 1.0×10?5 M for DA and 1.0×10?5 to 1.0×10?3 M for AA, respectively. The method was successfully applied for simultaneous determination of UA, DA and AA in human urine samples. 相似文献
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SUN Ying-hua LI Xiao-ping MEI Ze-min ZHU Yu NIU Li . State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun P. R. China 《高等学校化学研究》2011,27(1):6-10
A new inorganic-organic hybrid tetravanadate [Co(2,2′-bpy)3]2V4O12·11H2O(1) has been prepared and characterized. X-Ray diffraction study reveals that compound 1 contains classical cluster anions [V4O12]4–, coordinated cations [Co(2,2′-bpy)3]2+ and eleven water molecules, in which an interesting decamer water cluster is formed. The hybrid nanoparticles were firstly used as a bulk-modifier to fabricate a chemically modified paste electrode (1-CPE). The electrochemical behavior and electrocatalysis of 1-CPE ha... 相似文献
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Poly(3,4‐ethylenedioxythiophene) (PEDOT) modified microelectrodes were prepared by electropolymerisation of the relevant monomer from CH3CN or H2O solutions. The electrochemical behaviour of the obtained coatings was investigated by cyclic voltammetry in both organic and aqueous media. The anodic responses obtained for a typical benchmark analyte such as ascorbic acid was used to test the different coatings; calibration curves were built up in order to evaluate the repeatability of the response and the reproducibility of the prepared sensing system. Moreover, the ability of the modified microelectrodes to work in low conductivity media was studied, and exploratory tests in dense food matrix was performed. 相似文献
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《Analytical letters》2012,45(2):175-192
ABSTRACT The preparation and electrochemical characteristics of electrodes modified by cobalt complexes of N, N' - bis(salicylidene)-ethane -1, 2- diamine (salen) are described. A cobalt-salen polymer film modified electrode has strong electro-catalytic effects for the oxidation of ascorbic acid. The anodic peak potential of ascorbic acid shifted negatively for 400 m V. The catalytic reaction rate constant determined by rotating disk experiments is 7.08×105 mol s?1 cm3. The catalytic mechanism and the effect of film thickness are discussed. A sensitive voltammetric response for ascorbic acid was obtained covering a linear range from 1.0×10?6 to 1.0×10?3 mol-L?1 The modified electrode showed good stability and reproducibility. The electrode was used to the determination of ascorbic acid in fruit juices and showed promising results compared with conventional methods. The electro-catalytic effect of several metal-salen complexes and a similar Schiff base derivative for ascorbic acid was compared. 相似文献
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单分子层γ-氨基丁酸共价修饰玻碳电极同时测定多巴胺、尿酸和抗坏血酸 总被引:15,自引:0,他引:15
采用电氧化法制备了一种新型γ-氨基丁酸(ABA)修饰的玻碳电极.X射线光电子能谱(XPS)和循环伏安法研究表明,ABA以单分子层状态以C—N键牢固地共价键合在电极表面.该修饰电极对多巴胺(DA)、尿酸(UA)和抗坏血酸(AA)都具有良好的电化学催化特性.在pH=7.0磷酸缓冲溶液中,DA,UA和AA分别于0.45,0.25和0.07V(vs.Ag/AgCl)有一个良好的、独立的阳极方波伏安峰,表明此修饰电极可用于这3种物质的同时测定.与DA,UA和AA的方波伏安峰电流呈线性关系的浓度范围分别为4.0~400,2.0~500和1.0~600μmol/L,检测限(3δ)分别为1.6,1.2和0.8μmol/L.该修饰电极具有良好的灵敏度、选择性和稳定性,并具有抗污染能力. 相似文献
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聚乙烯醇修饰电极的研制及应用 总被引:3,自引:0,他引:3
本文提出用玻碳电极为基体制作聚乙烯醇(PVA)修饰电极。研究了铜在该电极上的阳极溶出伏安特性。探讨了电极修饰及其作用机理。电极可用于水中痕量铜的测定,灵敏度比未修饰玻碳电极提高一个数量级以上。 相似文献
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Electrocatalytic and Simultaneous Determination of Ascorbic Acid,Nicotinamide Adenine Dinucleotide and Folic Acid at Ruthenium(II) Complex‐ZnO/CNTs Nanocomposite Modified Carbon Paste Electrode 下载免费PDF全文
Hassan Karimi‐Maleh Fahimeh Tahernejad‐Javazmi Marzieh Daryanavard Hassan Hadadzadeh Ali A. Ensafi Maryam Abbasghorbani 《Electroanalysis》2014,26(5):962-970
This paper describes the development a novel ruthenium(II) complex‐ZnO/CNTs modified carbon paste electrode (Ru(II)/ZnO/CNTs/CPE) for the electrocatalytic determination of ascorbic acid (AA). The objective of this novel electrode modification was to seek new electrochemical performances for the detection of AA, nicotinamide adenine dinucleotide (NADH) and folic acid (FA). The peak potentials recorded were 170, 500 and 830 mV vs. Ag/AgCl/KClsat for AA, NADH and FA, respectively. The peak currents were linearly dependent on AA, NADH and FA concentrations using square wave voltammetry (SWV) method at the ranges of 0.008–251, 1.0–650, and 3.0–700 µmol L?1, with detection limits of 0.005, 0.5, and 1.0 µmol L?1, respectively. 相似文献
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聚吡咯水杨酸修饰电极的电化学行为及水杨酸含量测定 总被引:10,自引:0,他引:10
本用电化学方法制备了聚吡咯-水杨酸修饰电极;并进行了电化学行为的研究,经电化学处理该是电极对水杨酸根具有选择性响应,响应线性范围在1.0×10^-^5-1.0×10^-^3mol/L之间。电极斜率为40mV/pC,该电极具有较好的稳定性,响应时间在180-300s之间;电极寿命可达60d。 相似文献
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铁氰化镍修饰电极对抗坏血酸电催化氧化的研究 总被引:5,自引:0,他引:5
抗坏血酸(AH_2)在玻碳和铂电极上的过电位较大,其电极反应不可逆.有关AH_2在碳及其它修饰电极上的电催化氧化已有一些报道,如减压热处理、Al_2O_3微粒研磨、普鲁士蓝修饰膜和聚乙烯二茂铁修饰膜等.本文研究了铁氰化镍修饰膜电极催化AH_2氧化的电化学行为.发现其阳极峰电流与AH_2浓度呈线性关系,可测定1×10~(-7)mol/L的AH_2,其灵敏度比聚乙烯二茂铁修饰电极提高一个数量级.用于蔬菜、水果中AH_2的测定,结果满意. 相似文献
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花椰菜组织膜—苯醌修饰电极测定L—抗坏血酸的研究 总被引:7,自引:0,他引:7
苯醌作为电子传递介体,石墨电极为基体电极。含有苯醌的聚氯乙烯薄膜固定在石墨电极上,然后将花椰菜组织肉浆固定在苯醌修饰电极上。用电流法测定L-抗坏血酸浓度,其线性响应范围为5.66×10^-^4-5.66×10^-^2mol/L。电极寿命至少30天。将电极用于药物中L-抗坏血酸含量分析,结果与药典法相符。 相似文献
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Copper complex dye (C.I. Direct Blue 200) film modified electrodes have been prepared by multiple scan cyclic voltammetry. The effect of solution pH and nature of electrode material on film formation was investigated. The optimum pH for copper complex film formation on glassy carbon was found to be 1.5. The mechanism of film formation on ITO seems to be similar to that on GC surface but completely different mechanism followed with gold electrode. Cyclic voltammetric features of our modified electrodes are in consistent with a surface‐confined redox process. The voltammetric response of modified electrode was found to be depending on pH of the contacting solution. UV‐visible spectra show that the nature of copper complex dye is identical in both solution phase and after forming film on electrode. The electrocatalytic behavior of copper complex dye film modified electrode towards oxidation of dopamine, ascorbic acid and reduction of SO52? was investigated. The oxidation of dopamine and ascorbic acid occurred at less positive potential on film electrode compared to bare glassy carbon electrode. Feasibility of utilizing our modified electrode in analytical estimation of dopamine, ascorbic acid was also demonstrated. 相似文献
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In the present work an aluminum electrode was modified with thin layer of metallic palladium. The ability of the electrode for electrooxidation and subsequent differential pulse voltammetric determination of paracetamol (PCT), ascorbic acid (AA) and codeine (CO) was evaluated. The results obtained indicated that a linear range from 0.1–3 mM and a detection limit of 5 μM for both three compounds is accessible. The peak separation of AA, PCT and CO is more than 300 mV large enough, allowed simultaneous determination of these compounds. The proposed method was applied for determination of AA, PCT and CO in some real samples. 相似文献
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木质素活化改性制备酚醛树脂胶黏剂研究进展 总被引:1,自引:0,他引:1
木质素由于化学结构与苯酚相似,通过活化改性可部分替代苯酚制备木质素改性酚醛树脂胶黏剂。既可降低成本、达到生物质资源高效利用的目的,并且制备的木质素改性酚醛树脂胶黏剂有毒残余较低,具有环保意义,是合成制备生物质高分子材料的重要途径。本文综述了国内外研究人员在木质素活化改性制备酚醛树脂胶黏剂研究领域的最新进展,重点介绍了化学改性、物理改性、生物改性等木质素活化改性方法,比较了不同改性产物制备酚醛树脂胶黏剂的性能,并对影响木质素活化改性制备酚醛树脂胶黏剂实现工业化应用的主要因素进行了分析。 相似文献