共查询到20条相似文献,搜索用时 15 毫秒
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Bin Fang Hongying Liu Guangfeng wang Yunyou Zhou Shoufeng Jiao Xianguo Gao 《应用聚合物科学杂志》2007,104(6):3864-3870
A novel modified electrode was fabricated with 9‐aminoacridine by electropolymerization in the phosphate buffer solution (PBS) (pH 7.4) and was characterized by cyclic voltammetry (CV). The modified electrode showed excellent electrocatalytic effect and high stability toward the electrochemical oxidation of dopamine (DA) and ascorbic acid (AA). Also, it showed a high stability for the determination of DA and AA simultaneously. Well‐separated voltammetric peaks were observed for DA and AA on the modified electrode. The separation of two anodic peaks was 170 mV, which was large enough to eliminate the interference of AA and determine DA. The differential pulse voltammograms (DPV) were used for the measurement of DA by means of the poly(9‐aminoacridine)‐modified electrode in PBS at pH 7.4. A linear response toDA was observed in the concentration range from 1.5 × 10?6 to 3.5 × 10?3 mol L?1 with a correlation coefficient of 0.9998 and a detection limit (S/N = 3) of 1.0 × 10?7mol L?1. The proposed method was used to determine DA in DA‐hydrochloride injection and showed excellent sensitivity and recovery. The ease of fabrication, good reproducibility, high stability, and low cost of the modified electrode are the promising features of the proposed sensor. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3864–3870, 2007 相似文献
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In this work, the composite carbon-polyvinylchloride (C-PVC) was used as an electrode for the detection of dopamine, ascorbic acid, uric acid and their mixtures by differential pulse voltammetry (DPV). The results showed that the untreated C-PVC electrode was selective and stable for the oxidation of dopamine in a mixture containing uric acid and an excess of ascorbic acid in acidic medium. The pre-treated C-PVC electrode in a neutral medium exhibited good resolution of the mixture components in the micro molar concentration range of DA. The ageing of the C-PVC electrode during longer time periods did not affect the peak potential and the detection of dopamine, uric acid and ascorbic acid in 0.1 M H2SO4. The practical analytical utility of the C-PVC electrode was demonstrated by the measurement of uric acid in human urine and serum samples without any preliminary pre-treatment. 相似文献
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制备了对苯二酚聚合膜修饰玻碳电极(PHQ/GCE),研究了多巴胺(DA)和L-色氨酸(L-Trp)在该电极上的电化学行为,以及支持电解质、溶液pH、扫描速率等对DA和L-Trp伏安响应的影响.实验发现,在pH 5.5的NaH2PO4-Na2HPO4缓冲溶液中,可用PHQ/GCE测定溶液中的DA和L-Trp,两者氧化峰电流均与浓度在1×10-3~5×10-6 mol/L范围内呈良好线性关系,相关系数分别为0.998 3和0.996 5,检出限分别为1×10-6 mol/L和5×10-7 mol/L,该方法简便快捷. 相似文献
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制备了羧化多壁碳纳米管/维生素B12修饰玻碳电极,利用循环伏安法研究了多巴胺(DA)在此修饰电极上的电化学行为。结果表明,在pH为6.48的PBS缓冲溶液中,此修饰电极对DA有很强的电催化作用,明显增强了峰电流,峰电位差ΔEp由196 mV减小至69 mV,提高了电极反应的可逆性。在优化实验条件下,此修饰电极所测DA氧化峰电流与DA浓度在1.0×10-5~5.0×10-5mol/L及1.0×10-3~1.0×10-2mol/L范围内均呈线性,线性方程分别为y=373.78x+71.726(R2=0.995 8)和y=57.2x+365.22(R2=0.986 6),其中低浓度区的相关系数较高,应用于实际样品测定时结果较为满意。检测限可达8.0×10-8mol/L。 相似文献
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Subhendu Bhandari 《国际聚合物材料杂志》2016,65(11):543-549
Polyaniline (PAni) was electrochemically synthesized from aniline sulfate (AS) in the presence and in absence of H2SO4 using Cu counter electrode. No significant corrosion of the Cu electrode was found while synthesizing from AS in presence of H2SO4, whereas relatively higher corrosion of Cu as well as contamination of synthesized PAni with corroded Cu were observed for the synthesis from aniline in presence of H2SO4 or from AS in the absence of H2SO4. Corrosion-free synthesis yields PAni free from contamination of Cu and exhibits smaller particle size and superior electrical and supercapacitive behavior compared to the process exhibiting corrosion of counter electrode. 相似文献
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A polyaniline-multi-walled carbon nanotubes (PANI-MWCNTs) composite modified electrode was fabricated and the electrochemical behaviors of acetaminophen on the PANI-MWCNTs composite modified electrode were investigated by using cyclic voltammetry (CV), single-potential step chronocoulometry and square-wave voltammetry (SWV). The results showed that this electrode exhibited excellent electrocatalytic effects on the redox of acetaminophen. Consequently, a simple and sensitive electroanalytical method was developed for the determination of acetaminophen. The oxidation peak current was proportional to the concentration of acetaminophen from 1.0 × 10−6 to 1.0 × 10−4 mol/L and 2.5 × 10−4 to 2.0 × 10−3 mol/L, respectively. The detection limit was 2.5 × 10−7 mol/L. The proposed method was used to detect acetaminophen in Composite Chlorzoxazone Tablets and the results were satisfying. 相似文献
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纳米材料构建的化学修饰电极用于多巴胺电化学检测已经被广泛研究。当前电极研究策略主要为采用复合材料并构建三维结构以增大吸附表面积。本综述总结了目前常用的纳米碳修饰材料与纳米金属修饰材料,比较分析了其表面结构形貌对多巴胺吸附的影响及吸附机制,总结了目前常用的构建三维修饰电极的方法。分析结果表明,相对于一维形貌,三维形貌结构的修饰电极往往具有更好的检测能力,三维结构不仅能显著增大表面积,提供更多的吸附位点,还可能产生“薄膜效应”,该效应在一定程度上能提高响应灵敏度,但超过一定限度会减缓响应时间,第一性原理分析表明,多巴胺在纳米修饰电极材料表面的吸附机制是化学吸附。最后指出了在改进修饰电极结构设计合理性、增强抗干扰性和提高选择性,以及新的检测控制机制分析方面需要进一步研究。 相似文献
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采用重氮盐电化学还原的方法对掺硼金刚石薄膜电极进行氨基化改性,光电子能谱(XPS)证明表面N元素的存在,同时可以通过406 eV、400 eV峰强度的变化,证明硝基还原为氨基。以Fe(CN)6-3/-4氧化还原电对为探针,进一步证明了氨基层的存在。采用循环伏安法和差分脉冲伏安法研究了改性后电极的电化学行为。通过分别检测多巴胺和抗坏血酸以及它们的混合溶液,表明选用差分脉冲伏安法,氨基化改性掺硼金刚石薄膜电极能够有效分离检测两者的氧化峰,分离后两峰电势差约为0.3 V。电极表面吸附血浆蛋白后,阻碍了Fe(CN)6-3/-4氧化还原对的电子传递,但是并不妨碍多巴胺的检测。 相似文献
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铝试剂能在玻碳电极表面电聚合成膜, 该膜能电催化氧化抗坏血酸、亚硝酸根。催化峰电流与其浓度均成良好的线性关系, 该聚合膜修饰电极具有良好的稳定性, 具有分析应用的意义。 相似文献
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复合氧化剂在合成导电聚苯胺中的应用 总被引:3,自引:0,他引:3
以苯胺为单体,采用(NH4)2S2O8和抗坏血酸组成的复合氧化剂,在硫酸水溶液中,用化学氧化法直接合成导电聚苯胺。系统地研究了复合氧化剂配比、硫酸的浓度、氧化剂浓度等因素对苯胺聚合反应的影响。结果表明,该方法聚合反应的最佳条件为:在10~25℃的温度范围内,不加氮气保护条件下,苯胺1.0 mol/L,H2SO41 mol/L,(NH4)2S2O81 mol/L,(NH4)2S2O8/抗坏血酸(C6H8O6)的配比为10∶1,合成了电导率达1.33 S/cm、产率达82.17%的聚苯胺。通过红外光谱和X衍射研究了通过不同氧化剂聚合得到聚苯胺的结构变化,结果表明,复合氧化剂氧化聚合得到的聚苯胺结晶比通过过硫酸胺作氧化剂聚合得到的聚苯胺结晶好,并且相应基团在红外光谱上发生红移。 相似文献
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J. Maciejewska K. Pisarek I. Bartosiewicz P. Krysiński K. Jackowska A.T. Bieguński 《Electrochimica acta》2011,(10):2344
We report here on a simple tyrosinase (TYR) modified electrode designed through the covalent bonding of the enzyme with poly (indole-5-carboxylic acid) (PIn5COOH) conducting polymer. This electrode was applied to the amperometric detection of dopamine (DA) in the presence of ascorbic acid (AA), uric acid (UA) and their mixtures, in the concentration range and ratios similar to those found in blood serum. Our experiments demonstrate that the presence of these interferents (AA, UA) does not affect the selectivity of such electrode towards dopamine with linear concentration dependence in the range of 0.5–20 μM, depending on the experimental conditions, however its sensitivity depends on the type and amount of interferent present. The lower limit of detection of DA in the presence of high AA (1000 fold) or UA (500 fold) concentration was found to be 0.1–0.5 μM. The sensitivity for DA detection is 6.2 A/M cm2 with UA and 2.3 A/M cm2 with AA present as interfering agents. For both interferents present in the ratio 12.5:1 (AA:UA), the sensitivity drops to the value of ca. 1.3 A/M cm2. The Michaelis–Menten (KM) constant and Imax values were evaluated, showing improved electrode sensitivity towards dopamine as judged from the decrease of the Michaelis–Menten constant. 相似文献
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以低密度聚乙烯(PE)为基体材料,乙烯-醋酸乙烯共聚物(EVA)为增韧剂,聚苯胺(PAn)和炭黑(CB)为导电添加剂制备复合电极板,探讨了原料配比对物理力学性能、电学性能的影响。结果表明,原料配比PE∶EVA∶CB=75%∶5%∶20%时,电极的电阻最小,但是其韧性不佳;当原料配比PE∶EVA∶(CB+PAn)=85%∶5%∶10%时,复合电极板具有最好的韧性能。 相似文献
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T. Selvaraju 《Electrochimica acta》2007,52(9):2998-3005
The copper was deposited on glassy carbon (GC) and indium tin oxide (ITO) electrodes by electrochemical method. The copper structures on electrode were characterized by atomic force microscope, X-ray diffractometeric pattern and differential pulse voltammetric studies. Optimal conditions for uniform growth of copper structures on the electrode were established. Voltammetric sensor was fabricated using the copper deposited GC electrode for the simultaneous detection and determination of uric acid (UA) and homovanillic acid (HVA) in the presence of excess concentrations of ascorbic acid (AA). The voltammetric signals due to AA and UA oxidation were well separated with a potential difference of 400 mV and AA did not interfere with the measurement of UA and HVA at the GC/Cu electrode. Linear calibration curves were obtained in the concentration range 1-40 μM for AA and 20-50 μM for UA at physiological pH and a detection limit of 10 nM of UA in the presence of 10-fold excess concentrations of AA was achieved. The simultaneous detection of submicromolar concentrations of AA, UA and HVA was achieved at the GC/Cu electrode. The practical utility of the present GC/Cu modified electrode was demonstrated by measuring the AA content in Vitamin C tablet, UA content in human urine and blood serum samples with satisfactory results. 相似文献
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