碳糊电极和化学修饰碳糊电极的制备及性能综述

碳糊电极在电化学研究中起着非常重要的作用．从电极材料选用和修饰剂选择方面综述了碳糊电极和化学修饰碳糊电极制备的几种方法,分析了碳糊电极和化学修饰碳糊电极制备技术存在的主要问题及其原因,评价了碳糊电极和化学修饰碳糊电极的表征技术、性能以及影响电极性能的因素．概括了近年来本课题组在碳糊电极研究中的一些结果．     

碳糊电极电位滴定法滴定氯(Ⅰ)

氯元素是人体液中重要组成部分,Cl~-浓度对人体健康有很大影响.因此,国际上饮用水质标准为含Cl~-200mg/L.目前碳糊电极广泛应用于有机物的测定,但测无机离子的工作尚少,还没有人用碳糊电极作为滴定氯离子的指示工具.目前传统电分析方法是Ag电极为指示电极,但银电极价格较贵.本文首次采用碳糊电极(不含活性物质)电位滴定Cl~-,终点电位变化明显、直观.     

PVC-碳糊修饰电极的研制

研制了二茂铁修饰PVC-碳糊电极，采用循环伏安法研究了在pH7．4 KH2PO4-Na2HPO4缓冲溶液中该修饰电极的电化学特性和该修饰电极对抗坏血酸和邻苯二酚的电催化作用，测定结果具有较好的灵敏度和线性关系。研制了α-安息香肟修饰PVC-碳糊电极，研究了该电极对铜(Ⅱ)的特殊选择性。同时初步探讨了电极与铜(Ⅱ)的反应机理。     

碳糊电极在硫化矿发电浸出过程中的应用研究

应用线性电势扫描法研究硫化矿的纯矿电极与碳糊电极体系在氯化钠电解液中的电化学行为.结果表明,乙炔黑在硫化矿浸出过程中起到电催化作用,加入乙炔黑的碳糊电极较之纯矿电极,其发电浸出输出电流和电压均有一定程度的增加,同时活化能较传统浸出的低.     

分析化学中的化学修饰碳糊电极

对化学修饰碳糊电极的发展原因、电极制备及性能、富集机理等方面以及近5年来在电化学分析中的发展和应用进行了评述。引用文献共73篇。     

石墨烯/十二烷基硫酸钠复合物修饰碳糊电极测定氯霉素

以液体石蜡和硅油为混合粘合剂,与石墨粉混合制备了碳糊电极基底电极,将石墨烯/十二烷基硫酸钠复合物修饰在基底碳糊电极上,得到了基于石墨烯复合物的新型修饰碳糊电极。应用扫描电镜和循环伏安法分别研究了该电极的表面特性和电化学性质,结果表明,石墨烯和十二烷基硫酸钠修饰的碳糊电极增大了比表面积,有利于电子传递。在pH 3.0的HAc-NaAc缓冲溶液中,该修饰碳糊电极对氯霉素具有良好的电化学响应,氧化峰电位为0.194 V,氧化峰电流是基底碳糊电极的10倍。在最优实验条件下,该氧化峰电流与氯霉素的浓度在1.0×10~(-8)~5.0×10~(-4)mol/L范围内呈良好的线性关系,检出限为5.0×10~(-9)mol/L。该方法简便,重现性及选择性好,用于测定氯霉素滴眼液和虾中氯霉素残留,结果满意。     

蒙脱石-石墨-聚氯乙烯复合电极的研制

化学修饰电极自1975年正式问世以来^[1],经过多年的不断发展,现已出现了许多修饰方法^[2];如表面吸附法,聚合物薄膜法,共价键合法等。这些方法虽在一定程度上改善了修饰电极的表面结构,提高了电极的灵敏度和选择性,但由于此类修饰都是在电极表面附上一层修饰剂,容易因修饰层不牢而脱落,或修饰厚度不均匀而影响电极的性能,近年来出现了组合法制作碳糊电极^[3]及蒙脱石修饰碳糊电极^[4]的研究,但由于碳糊及其修饰电极存在电极表面柔软的缺点而使其生理性,稳定性欠佳,本文用聚氯乙烯作粘合剂,在其融状态下,将石墨和蒙脱石混合,加压,冷却制成复合电极,该复合电极用于苯酚测定时,表现出良好的稳定性,重现性和催化效果,并克服了蒙脱石修饰碳糊电极稳定性,重现性差的缺点。     

pH值对有机化合物富集与伏安溶出过程的影响

在碳糊电极上有机化合物的富集能够增加溶出伏安法的灵敏度和选择性。不同的有机化合物的碳糊电极上的富集机理不同,在电极上的伏安溶出条件也不同。使用碳糊电极时,对有机化合物的富集、溶出影响因素是多方面的,其中富集液和溶出液的ｐＨ值对它的影响十分重要文中通过碳糊电极对一些简单有机体例物如氯丙嗪（冬眠灵）、丁基羟基甲醚（ＢＨＡ）、Ｎ,Ｎ－二甲基苯胺（ＤＭＡ）、对苯二酚的富集与伏安溶出进程的研究,从理论和试验     

细菌修饰的碳糊电极表面超细微粒金膜的制备及应用

本文提出一种采用电化学方法在巨大芽孢杆菌Ｄ０１修饰的碳糊电极表面制备超细微粒金膜的新方法,获得由平均粒径为８０ｎｍ金微粒组成的金膜。该方法操作简单,耗金量少,以此金膜作为工作电极检测水溶液中痕量铜具有良好的重现性和线性,检测灵敏度达０．０２ｎｇ／ｍＬ,该电极既可象金片电极多次反复被使用,也可以象碳糊电极一样不断更新表面。     

镍纳米粒子修饰碳糊电极直接电催化鸟嘌呤的研究

将镍纳米粒子与石蜡、石墨按照一定比例混合制备镍纳米粒子修饰碳糊电极,采用循环伏安法(CV)对修饰碳糊电极进行电化学表征,在0.1 mol/L B-R缓冲溶液(pH4.5)中研究了鸟嘌呤在该修饰电极上的电化学行为。结果表明,与裸碳糊电极相比,以掺杂法制备的镍纳米粒子修饰电极能够明显降低鸟嘌呤的过电位,增大其氧化电流,很好地催化氧化鸟嘌呤。在优化的实验条件下,鸟嘌呤在该修饰电极上的氧化峰电流与其浓度在1.0×10-5~5.0×10-4mol/L范围内呈良好的线性关系,检出限(3σ)为7.5×10-6mol/L。     

Behavior of Glassy Carbon Paste Electrode in Flowing Methanolic Solutions

Carbon paste electrodes are often used for electrochemical determinations, but their application in media with high content of organic solvents, particularly in HPLC, is limited by their low stability. The work presented here examines the effect of a moving methanol‐containing solution on a glassy carbon paste electrode by studying its electrochemical behavior in relation to the period of contact and methanol content in the solution. In combination with microscopic observation of the paste surface it can be concluded that the electrode is affected by the methanolic solution and the surface roughness increases, resulting in the stable state compatible with measurements in highly methanolic solutions.     

嵌入式超薄微晶纤维素/碳糊电极的构建及其应用研究

本文以镍铬合金为基体构建了嵌入式超薄微晶纤维素/碳糊电极,该电极是在镍铬合金表面通过直接嵌入微晶纤维素修饰的碳糊膜而制成的。以抗坏血酸为目标物考察其在该电极上的电化学行为,结果表明合金表面嵌入的超薄微晶纤维素/碳糊膜改变了基体电极的电化学性质,扫描电镜表征电极表面形貌,电化学方法考察了该电极对AA的响应。该电极对AA的电氧化显示了良好的增敏作用,可用于实际样品中AA的测定。     

Glassy carbon paste electrodes

A new carbon composite electrode material, based on mixing glassy carbon (GC) microparticles with an organic pasting liquid is described. The resulting glassy carbon paste electrode (GCPE) combines the electrochemical properties of GC with the various advantages of composite electrodes. Glassy carbon pastes (GCPs) offer high electrochemical reactivity, a wide accessible potential window, a low background current, and are inexpensive, easy to prepare, modify, and renew. The new material has a lower double-layer capacitance and a higher heterogeneous rate constant (for ferricyanide) compared to conventional carbon pastes (CPs). Scanning electron microscopy (SEM) images indicate significant differences in the structure of GCPE and carbon paste electrode (CPE). Factors influencing the electrode kinetics of GCPE surfaces are discussed. The electrochemical properties and advantages of GCPE should be of broad utility in electroanalysis.     

Electrochemical response of a carbon paste electrode containing an adsorbed species on incorporated alumina

The electrochemical response of carbon paste electrode was investigated containing an inorganic and a non-electroactive compound on which an electro- active organic molecule was adsorbed. Alizarin S was chosen as the test molecule adsorbed on 150 m²/g of alumina, because this molecule is either easily reduced or oxidized on carbon. The electrode response was found to be linear for low amounts of alumina containing a known amount of Alizarin S. The electrical yield was never higher than 50%, but was reproducible. An increasing alumina amount in the paste increased the response, but lowered the electrical yield.     

硫脲在10-甲基吩噻嗪修饰碳糊电极上的电催化氧化及电分析方法研究

研究了硫脲(Thiourea,Tu)在10-甲基吩噻嗪修饰碳糊电极(MPT/CPE)上的电催化氧化行为.结果表明,Tu在裸碳糊电极(CPE)上的直接电化学氧化过程十分迟缓,MPT/CPE对Tu的电化学氧化具有良好的催化作用.用计时电流法(CA)测定了Tu在MPT/CPE上的电极过程动力学参数,测得电荷传递系数α=0.61,电催化氧化反应的速率常数k=(1.96±0.10)×104(mol/L)-1·s-1.用方渡伏安法(SWV)测得催化氧化峰电流与Tu浓度在1.0×10-6～8.0×10-3mol/L范围内呈良好的线性关系,线性回归方程为,Ips(μA)=10.836c(10-3mol/L)+5.326,R=0.9984,检出限为2.2×10-7mol/L(S/N=3).方法可用于Tu的电化学法测定.     

Electrocatalytic oxidation of dopamine at an ionic liquid modified carbon paste electrode and its analytical application

A room-temperature ionic liquid N-butylpyridinium hexafluorophosphate was used as a binder to construct an ionic liquid modified carbon paste electrode, which was characterized by scanning electron microscopy and electrochemical impedance spectroscopy. The ionic liquid carbon paste electrode (IL-CPE) showed enhanced electrochemical response and strong analytical activity towards the electrochemical oxidation of dopamine (DA). A pair of well-defined quasireversible redox peaks of DA appeared, with the redox peaks located at 215 mV (E _pa) and 151 mV (E _pc) (vs. the saturated calomel electrode, SCE) in pH 6.0 phosphate buffer solution. The formal potential (E ^0′) was calculated as 183 mV (vs. SCE) and the peak-to-peak separation as 64 mV. The electrochemical behavior of DA on the IL-CPE was carefully investigated. Under the optimal conditions, the anodic peak currents increased linearly with the concentration of DA in the range 1.0 × 10⁻⁶–8.0 × 10⁻⁴ mol/L and the detection limit was calculated as 7.0 × 10⁻⁷ mol/L (3σ). The interferences of foreign substances were investigated and the proposed method was successfully applied to the determination of DA injection samples. The IL-CPE fabricated was sensitive, selective and showed good ability to distinguish the coexisting ascorbic acid and uric acid.     

吡啶类碳离子液体电极对酚磺乙胺的电化学行为及其分析应用

用离子液体1-丁基吡啶六氟磷酸盐(BuPyPF6)作为粘合剂构置了碳离子液体修饰电极(BuPyPF6-CILE).在0.05 mol/L H2SO4溶液中,用循环伏安法研究了在BuPyPF6-CILE和传统碳糊电极(TCPE)上酚磺乙胺(ESL)的电化学行为,建立了测定尿样和血清样品中ESL含量的新方法.ESL在BuPyPF6-CILE上的氧化峰电流响应是其在TCPE上的8.7倍,峰电位差降低到0.101 V,电子转移速率常数Ks=0.544 s-1,电极表面平均吸附量为1.66×10-9 mol·cm2.ESL的氧化电流与其浓度在8.0×10-8～2.0×10-6mol/L和5.0×10-6～1.0×10-4mol/L范围内呈线性关系,检出限为3×10-8mol/L(S/N=3).连续5次测定2.0×10-6mol/L ESL溶液的RSD为1.5%.     

Preparation and characterization of carbon paste micro-electrode based on carbon nanoparticles

The present paper demonstrates the preparation and characterization of micro-electrodes based on carbon paste which is composed of carbon nano-particles with an average diameter of 30 nm and binding oil. The carbon paste electrode material is encased in pulled glass capillaries ranging in diameter from several tens down to less than ten micro-meters (r = 4.5 μm). Manipulation of the carbon paste micro-electrode (CPME) was accomplished via newly developed piston-driven system which construction and related problems are presented. Several parameters influencing the CPME performance including carbon paste composition and its electrochemical activation/preconditioning were investigated. Basic electrochemical behavior and properties were examined using typical redox system, i.e. potassium hexacyanoferrate. Applicability of the proposed carbon paste micro-electrode is illustrated by measuring some potentially interesting organic and inorganic analytes such as dopamine, ascorbic acid and selected heavy metals.     

Electrochemical Determination of Dopamine Using a Carboxyl-functionalized Carbon Nanotube-Modified Carbon Paste Electrode Doped with Polymeric Ferric Sulfate

A novel electrochemical device for the sensitive determination of dopamine was developed based on a carbon paste electrode with polymeric ferric sulfate doped in the carbon paste and a carboxyl-functionalized carbon nanotube thin film on the surface. The modified electrode was characterized by scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. The conditions for the preparation of electrode were optimized. The carbon nanotubes were shown to be stable on the surface of carbon paste electrode. The novel electrochemical device provided excellent activity toward dopamine. Amperometry and differential pulse voltammetry were used for the determination of dopamine in pH 7.0 phosphate buffer with a long linear range from 0.8 to 261?µM and a detection limit of 0.2?µM. The modified electrode showed excellent repeatability, good stability, and satisfactory reproducibility, thus demonstrating potential for practical applications.     

Application of a nanostructured sensor based on graphene‐ and ethyl 2‐(4‐ferrocenyl[1,2,3]triazol‐1‐yl)acetate‐modified carbon paste electrode for determination of methyldopa in the presence of phenylephrine and guaifenesin

We introduce a new method to determine methyldopa without the interference of phenylephrine and guaifenesin. For this purpose, a carbon paste electrode was modified with graphene and ethyl 2‐(4‐ferrocenyl[1,2,3]triazol‐1‐yl)acetate. According to electrochemical studies, oxidation current of methyldopa on the surface of the modified electrode increased and shifted towards negative potentials. This modified electrode demonstrated two linear ranges of 0.4–30.0 μM and 30.0–500.0 μM with a detection limit of 0.08 μM. No change was observed in the sensitivity of the modified electrode towards methyldopa in the presence of phenylephrine and guaifenesin, which enables the simultaneous or independent measurement of the three moieties. The efficiency of the proposed modified electrode was evaluated through the determination of these substances in real samples.