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首先在玻璃毛细管外化学沉银,然后在银层上电解沉积Ag2S层,制得Ag/Ag2S固膜电极;与毛细管内的Ag/AgCl参比电极组装成复合电极系统。试验表明,该电极对CN-具有良好的能斯特响应,能斯特斜率约为110 mV/pCN-,线性范围为pCN-3~7,检测下限为5×10-8mol.L-1。应用此电极分析污水试样的结果与标准光度法的测定结果相符,两者的相对误差小于5.1%。试验了常见离子如S2-、Ag 、Hg2 等的干扰及其消除方法。讨论了电极的响应机理。 相似文献
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阿魏酸聚合修饰玻碳电极的制备及其对NADH的催化氧化 总被引:8,自引:0,他引:8
研究了阿魏酸修饰电极的制备、性质及对NADH的电催化作用.该电极在0.1mol/L磷酸缓冲溶液(pH=6.60)中,于-0.1~+0.50V(vs.Ag/AgCl)电位范围内呈现一对氧化还原峰,其式量电位E0为+0.188V(vs.Ag/AgCl),且E0随pH增加而负向移动.电子转移系数为0.496,表观电极反应速率常数(ks)为6.6s-1.电极反应的电子数为1且有1个质子参与.该修饰电极对NADH氧化具有很好的催化作用.在NADH存在下,电极过程由扩散控制,扩散系数为1.76×10-6cm2/s.NADH浓度在0.01~5.0mmol/L范围内与峰电流呈现良好的线性关系.通过计时安培法测得催化速率常数为6.82×103mol-1·L·s-1. 相似文献
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咖啡酸玻碳修饰电极对烟酰胺腺嘌呤二核苷酸的电催化氧化 总被引:1,自引:0,他引:1
研究了咖啡酸修饰电极的制备、性质及对NADH的电催化作用。修饰电极在0.1mol/L PBS缓冲溶液中(pH7.0)于0.0~ 050V(vs.Ag/AgCl)电位范围内呈现一对氧化还原峰,式量电位(E^0‘‘)为 0.250V(vs.Ag/AgCl)。E^0‘‘随pH增加而朝负方向移动,pH在5.0~8.0范围内,其线性回归方程为E^0‘‘=0.6233-0.05996pH,R=0.9969。表观电极反应速率常数(Kb)为12.3s^-1。电极反应的电子数为2且有2个质子参与。该修饰电极对NADH的氧化具有很好的电催化作用。NADH浓度在0.1—6.0mmol/L.范围内与峰电流呈现良好的线性关系。文中对电催化过程进行了探讨。 相似文献
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本文采用丝网印刷技术制备了一种基于聚酰亚胺(PI)柔性塑料基片的Ag/AgCl脑电电极,并建立了一套系统评价柔性脑电电极性能的方法。评价方法主要包括扫描电镜(SEM)表征、电极电位/时间响应和稳定性测试、电化学阻抗测试、附着性测试。结果表明,该柔性电极表面为多孔结构,且与基底粘附性好;该电极呈现Ag/AgCl的电化学界面性质,其平衡电位为0.97±0.20mV,与Ag/AgCl粉末电极接近;且电极电位一致性和稳定性良好,最大极差电位不超过0.7mV,4h后电位漂移值在10μV/4min以内;经磨砂导电膏GT5处理后,电极-皮肤阻抗在5kΩ以内,满足脑电记录要求;相对于人体皮肤的高阻抗值,柔性电极-导电膏(GT20)的界面阻抗仅为166Ω·cm2。该评价方法系统、实用,可为制定相应国家标准提供技术参考。 相似文献
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本文对乙酰螺旋霉素在GCE上的伏安行为进行了研究,发现在磷酸盐缓冲溶液(pH=7.87)中,於十0.85V(vs.Ag/AgCl)左右产生一良好的阳极氧化伏安峰.浓度在0.5~100μg/mL之间与峰电流呈线性关系,分析了制剂中乙酰螺旋霉素的含量,相对标准偏差为4.5%,平均回收率为101%.经循环伏安法验证,电极反应为不可逆反应. 相似文献
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血红蛋白在磷脂-月桂酸修饰的玻碳电极上的电化学行为及其分析应用 总被引:6,自引:0,他引:6
报道了血红蛋白(Hb)在磷脂-月桂酸修饰的玻碳电极上的电化学行为,在+0. 8~-0.7V (vs. Ag/AgCl)电位范围内,于pH6.0的0.01mol/L的KH_2PO_4- Na_2HPO_4底液中,血红蛋白产生不可逆的还原电流峰。还原峰电流与血红蛋白浓 度在1.25 * 10~(-8)~4.31 * 10~(-7) mol/L范围内呈良好线性关系。该电极可作 为检测血红蛋白的新型的高灵敏度电化学生物传感器。 相似文献
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The influence of various factors such as solubility, the oxidation of the membrane, and the contamination of the solution, on the experimental values of the selectivity coefficients of solid state sulphide ion selective electrodes is discussed. A new method for the evaluation of very small selectivity coefficients, based on the addition of reagents forming complexes or insoluble salts with the main ion, is proposed. By means of this method, selectivity coefficients for silver, copper, cadmium and lead ion selective electrodes have been determined, which are in far better agreement with thermodynamic values than those described in the literature. 相似文献
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用氧化还原聚合物修饰多孔电极 总被引:1,自引:0,他引:1
对3种类型Nafion/Os(bpy)3Cl2修饰电极的研究结果表明,单位表观电极面积上中继体载量比为:乙炔黑粉末微电极(A):Teflon粘结的乙炔黑膜电极(B):平面玻碳电极(C)=10^3:10^2:1.A比B及C更容易在真实表面上形成花天酒地而均匀的修饰层而有利于层内的电荷传递。在A类电极基础上制行的葡萄糖酶电极在10mmol/L葡萄糖溶液中的响应电流密度高达4.6×10^-^4A/cm^ 相似文献
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把玻璃参比电极、环状的银-硫化银指示电极、以及铂丝屏蔽电极组合形成新型硫醇硫组合电极,研究了在含有0.2 mol/L硫离子的醇-水-氨介质中,在表面活性剂存在下,以环状银电极为阳极,恒定微电流电沉积的方式制备硫化银敏感层的条件。由此法制得的新型硫醇硫组合电极在Ag 浓度为1.0×10-1~1.0×10-5mol/L范围内斜率为59.0±0.5 mV/pC,测量下限为2.2×10-6mol/L,与同类商品电极相比,响应速度快、记忆效应小、重复性好、电位稳定,易于批量生产,具有较强的适应性和应用价值。 相似文献
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在N-Si和P-Si半导体上用化学沉积法制备了内场致发射电极并研究了它们的电化学行为。从分解电势Ⅰ~Ⅴ曲线可知,这种电极可在低于1.23V下分解水;对Fe~(3+)/Fe~(2+)体系的循环伏安图,其峰电流为铂电极的8倍多。 相似文献
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Carbon nanotube, graphene and carbon black, as electrode modifiers, were compared and evaluated for the electrochemical determination of vancomycin. Among them, the best results were obtained at the graphene‐modified electrode. Additions of vancomycin using square wave voltammetry at the graphene‐modified electrode showed a linear range from 0.70 μM to 50 μM and a detection limit of 0.20 μM was obtained. To control the correct dose of vancomycin and reduce its side effects, its accurate determination in blood plasma is very important. Therefore, the method was applied for the vancomycin determination in spiked human plasma samples and satisfactory recoveries were observed. The developed method exhibited fast analysis, high sensitivity, good repeatability and freedom from other interfering species. 相似文献
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《Analytical letters》2012,45(12):1457-1463
Abstract Inexpensive, disposable, carbon-filled polymer paste reference electrodes are reported. These electrodes are designed for use in conjuction with carbon-filled polymer paste ion-selective probes reported earlier. Attachment of integrated electronics is easily achieved. 相似文献
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A verapamil-PVC membrane ion-selective electrode based on the verapamil-reineckate ion pair was prepared with dibutyl phthalate as a plasticizer. The electrode exhibited a linear response with a Nernstian slope (52.8 mV decade?1 at 20° C) for verapamil concentrations of 10?5?10?2M over the pH range 3–7. The electrode also exhibited very good selectivity for verapamil with respect to various inorganic and organic cations. Gran II linear titration and potentiometric titration were used to determine verapamil in pure solution, with an average recovery of 99.3% and a relative standard deviation of 0.4%. 相似文献
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Potentiometric electrodes were developed for the rapid determination of proguanil hydrochloride in pure samples, pharmaceutical preparations and spiked serum and urine samples using PVC membrane,screen printed(SPE), coated wired(CWE), carbon paste(CPE) and modified carbon paste(MCPE)electrodes based on the ion-exchanger of proguanil with phosphotungestic acid(Pr-PT) as a chemical modifier. The prepared electrodes showed Nernestian slopes of 59.7, 58.1, 58.5, 58.5 and 57.0 for the PVC,SPE, CWE, CPE and MCPE for the proguanil ions in a wide concentration range of 1.0 * 10~(-5)–1.0 * 10~(-2)mol L~(-1) at 25°C with detection limits of 7.94 * 10~(-6), 1.0 * 10~(-5), 1.0 * 10~(-6), 7.07 * 10~(-6) and 2.5 * 10~(-6) mol L~(-1), respectively. The prepared electrodes exhibited high proguanil selectivity in relation to several inorganic ions and sugars and they could be successfully utilized for its determination in pure solutions, pharmaceutical preparations and serum and urine samples using the direct potentiometry and standard addition methods with very good recovery values. 相似文献