基于石墨/聚吡咯电极的葡萄糖生物传感器

采用电化学聚合技术,在掺杂的导电聚吡咯薄膜修饰过的铅笔芯电极上,吸附葡萄糖氧化酶制备葡萄糖生物传感器。首先在含有0.1 mol/L吡咯和0.01 mol/L HCl的溶液中,于0.7 V恒电位下吡咯单体氧化聚合,在铅笔芯电极表面形成聚吡咯薄膜;然后将葡萄糖氧化酶吸附在修饰过的电极上制备出葡萄糖氧化酶-聚吡咯-铅笔芯电极电流型生物传感器。实验考察了吡咯聚合时间、聚合温度、葡萄糖氧化酶吸附量、检测电压以及干扰物对传感器性能的影响。实验结果表明,在优化条件下,传感器的灵敏度为17.78μA/mmol/L,线性范围0.8 mmol/L,线性相关度R=0.9918,响应时间小于16 s,检测下限为18.75μmol/L,有较强的抗干扰能力。     

磷钼杂多酸—碱性染料离子缔合物掺杂聚吡咯薄膜修饰石墨电极的研究

采用电化学聚合法研制了磷钼杂多酸－碱性染料离子缔合物掺杂聚吡咯薄膜修饰石墨电极，研究了修饰电极的电化学行为。     

电流型聚吡咯碘离子化学修饰电极的制备与性能研究

在玻碳电极(GCE)表面上修饰了一层导电聚合物 聚吡咯(Ppy)薄膜,用循环伏安法制备了新型的基于电流响应的掺杂碘离子的聚吡咯修饰电极;研究了电极的电化学特性。此修饰电极对碘离子的响应是基于碘离子在Ppy膜与电解质溶液中的掺杂平衡以及Ppy膜中的碘离子在修饰电极表面的氧化还原过程;制成的电流型电极对5 0×10-2mol/L～1 0×10-5mol/L的碘离子呈良好的线性响应关系,检出限为6 0×10-6mol/L。     

聚吡咯及包夹亚甲绿的聚吡咯修饰电极对血红蛋白电极过程的促进

用电化学聚合法制备的聚吡咯及包夹亚甲绿的聚吡咯薄膜修饰电极可以促进血红蛋白的非均相电子传递过程。用光透薄层光谱电化学技术测定了血红蛋白在包夹亚甲绿的聚吡咯修饰电极上的电子传递数(n),标准电极电位(E~(o'))和非均相电子传递速度常数(k_(εh)~o)。对血红蛋白在聚吡咯修饰电极上的电子传递反应机理进行了探讨。     

离子液体中吡咯的电化学聚合及性质研究

以1-丁基-3-甲基咪唑六氟磷酸盐离子液体作为溶剂和支持电解质,分别在铂电极和导电玻璃电极上电化学聚合得到了聚吡咯,聚合过程中发现,在离子液体中聚合的循环伏安图,其电流的变化和传统有机溶剂中的不同,通过交流阻抗技术研究了修饰电极的电化学性质,采用在线紫外、拉曼、红外谱对聚吡咯进行了光谱表征,得到了聚吡咯的特征峰,采用扫描电镜研究了聚合物的形貌。最后将修饰电极应用到了对对苯二酚的催化反应当中,显示了一定的催化作用。     

聚吡咯薄膜中茜素红S的电化学特性

利用循环伏安法研究了聚合电位和聚合电量对茜素红S掺杂聚吡咯薄膜修饰玻碳电极性质的影响,考察了不同电位范围内修饰电极的电化学特性.发现在茜素红S的氧化还原过程中存在着茜素红S分子与聚吡咯链的相互作用,且这一相互作用敏感于扫描正电位限.基于实验结果,提出了可能的茜素红S在电极表面聚吡咯膜内的氧化还原机理.     

同多钼酸掺杂的聚吡咯薄膜电极的制备及表征

用电化学聚合制备了同多钼酸掺杂的聚吡咯(IPMo/PPy)薄膜电极, 这种电极在硫酸水溶液中扫描时具有良好的稳定性,用循环伏安法,X射线光电子能谱(XPS), 现场紫外可见光谱电化学及电子自旋共振波谱(ESR)对这种修饰电极进行了表征     

导电高分子薄膜修饰电极的研究I. 聚吡咯薄膜电极的电化学合成及行为

利用在水溶液中的电化学聚合制备了聚吡咯烷、薄膜修饰电极. 讨论了对电化聚合的影响因素及薄膜修饰电极在不同电解质中的伏安特性, 从X-射线光电子能谱推测, 在吡咯的电化聚合过程中氧的参加引起在聚吡咯烷膜的结构中有羰基和羟基的生成.     

聚邻氨基苯甲酸-铜复合薄膜修饰电极的制备及其电化学性能

利用聚合物官能团对金属离子的配位作用,在电极表面原位制备了金属粒子。 首先在玻碳电极（GCE）表面电沉积聚邻氨基苯甲酸(PoABA),再化学吸附铜离子(Cu2+),用水合肼还原得到单质铜(Cu0)。 采用扫描电子显微镜和能谱分析表征了聚邻氨基苯甲酸 铜(PoABA-Cu0)复合薄膜的表面形貌和元素构成,研究了PoABA-Cu0修饰电极的电化学性能,并以其检测了过氧化氢（H2O2）。 结果表明,电极表面被修饰上了一层PoABA-Cu0复合薄膜;制备的修饰电极对H2O2具有良好的电催化性能,在邻氨基苯甲酸的聚合圈数为10、Cu2+的吸附时间为10 min、工作电压为-0.3 V时,该修饰电极对H2O2表现出了最佳的检测性能,其线性浓度范围为5.0×10-5～1.0×10-2 mol/L,灵敏度为96.3 μA·L/(mmol·cm),检测限为5.0×10-5 mol/L,且具有较好的稳定性。     

全固态锂离子选择性电极研究

研究了新型载体HPMBP-TOPO体系几种全固态锂离子选择性电极（涂丝电极、单层全固态电极、聚吡咯修饰层内接触电极）的性能。与传统型电极相比，固态电极响应斜率有所降低，而选择性稍有提高。其中聚吡咯修饰层内接触电极性能为最佳，该电极响应斜率为56.7mV/decade，并具有良好再现性和长期稳定性。     

Two-dimensional condensation of nucleic acid components at mercury film and gold electrodes

The adsorption of cytidine at the mercury film electrodes and at the Au (111) single crystal electrode has been investigated. Some kinetic aspects such as the influence of pH and temperature on the formation or dissolution of cytidine adlayer on the pyrolytic graphite electrode covered by a mercury film or on the Au (111) have been studied.     

Application of thin film mercury electrodes and solid amalgam electrodes in electrochemical analysis of the nucleic acids components: detection of the two-dimensional phase transients of adenosine

The optical diffractive (DOE)-based sensor was used to the study of the optical roughness of different carbon/graphite electrodes modified by mercury film (MFEs) and solid amalgam-alloy electrodes (S-MeAEs). The electrode surfaces were visualised by an optical metallurgical microscope. The adsorption of adenosine at the MFEs and S-MeAEs has been investigated by capacitance measurement. Some kinetics aspects, such as the influence of the surface morphology, nature of the substrate and thickness of the mercury film and amalgam-alloy on the formation of two-dimensional (2D) physisorbed adenosine adlayer on the MFEs and S-MeAEs, were studied.     

Thermogravimetric studies of benzoylthiourea-modified MCM-41 after adsorption of mercury ions from aqueous solutions

High-resolution thermogravimetry (HR TG) was used to study the adsorption of mercury(II) ions by modified MCM-41 material and regeneration of the loaded adsorbent with mercury ions by using different eluents. The weight change curves were measured for MCM-41 samples modified with 1-benzoyl-3-propylthiourea ligand loaded with mercury ions. The differential thermogravimetric (DTG) curves were analyzed to investigate the adsorption of mercury ions by the aforementioned multifunctional ligand and to monitor the decomposition of the metal-ligand complexes. A series of experiments performed for different Hg(2+):ligand ratios allowed us to correlate the adsorption data for mercury ions measured by means of UV spectrophotometry with those obtained by HR TG analysis. The DTG results provided additional information about mercury-ligand interactions as well as the thermal stability of mercury-ligand complexes. This study shows that HR TG is a very attractive technique for studying the adsorption of mercury ions on modified nanoporous silicas and monitoring their regeneration. Since the samples used are small, this method seems to be promising for studying adsorption systems of environmental significance.     

A Simulation of an Anion‐Induced Adsorption of Metal Ions in Pseudopolarography Using a Thin Mercury Film Covered Rotating Disk Electrode

A theory of the influence of anion‐induced adsorption of metal ions in pseudopolarography using the thin mercury film covered rotating disk electrode is developed. The model is developed assuming that the metal ion is forming several labile complexes with the ligand which is present in a great excess, and that only one complex species is adsorbed following a linear isotherm. The results obtained assuming steady‐state conditions are compared with the simulation of transient processes using Galerkin and finite difference methods. It is shown that the adsorption of metal complexes on the disk electrode surface does not prevent the determination of the stability constants.     

Study of an organically modified clay: selective adsorption of heavy metal ions and voltammetric determination of mercury(II)

In this work, a hydrophilic clay, Na-montmorillonite from Wyoming, USA, was rendered organophilic by exchanging the inorganic interlayer cations for hexadecyltrimethylammonium ions (HDTA), with the formulae of [(CH₃)₃N(C₁₆H₃₃)]⁺ ion. Based on fact that organo-clay has high affinities for non-ionic organic molecules, 1,3,4-thiadiazole-2,5-dithiol was loaded on the HDTA-montmorillonite surface, resulting in the 1,3,4-thiadiazole-2,5-dithiol-HDTA-montmorillonite complex (TDD-organo-clay).The following properties of TDD-organo-clay are discussed: selective adsorption of heavy metal ions measured by batch and chromatographic column techniques, and utilization as preconcentration agent in a chemically modified carbon paste electrode (CMCPE) for determination of mercury(II).The main point of this paper is the construction of a selective sensor, a carbon paste electrode modified with TDD-organo-clay, its properties and its application to the determination of mercury(II) ions, as this element belongs to the most toxic metals. The chemical selectivity of this functional group and the selectivity of voltammetry were combined for preconcentration and determination.     

Anodic Dissolution of Gold in Alkali–Cyanide Solutions Containing Microquantities of Mercury Ions

An admixture of mercury ions accelerates dissolution of gold at negative (in the hydrogen scale) potentials and hinders it at positive potentials. In contradistinction to a similar effect exerted by admixtures of thallium, bismuth, and lead ions, the influence of mercury ions, all other conditions being equal, manifests itself at much longer times of contact between gold and solution. This difference is due to a low rate of the act of adsorption (discharge) of mercury ions. The rate increases at more negative potentials, and at E –1.2 V (NHE) the act accelerates to such an extent that looses the limiting role, which passes to the stage of supply of mercury ions to the electrode, as with solutions containing thallium, bismuth, and lead. Comparing these results with earlier data on the adsorption of cyanide ions on gold shows that the discharge of the Hg(CN)^2- ₄ anions stops limiting the formation of a layer of mercury atoms when the adsorption of cyanide ions turns insignificant.     

Determination of traces of metals by anodic stripping voltammetry at a rotating glassy carbon ring—disc electrode: Part 1. Method and instrumentation with evaluation of some parameters

The equipment and procedure are described for the determination without preconcentration of several heavy metals based on d.c. anodic stripping voltammetry at a rotating ring—disc glassy carbon electrode with in situ mercury plating. During stripping of the metals deposited on the disc, the current from the reduction of the ions collected at the ring is measured. Some parameters (scan rate, thickness of the mercury film, electrode rotation and deposition time) influencing the ring collection peak current are examined experimentally. The results are compared with the theoretical considerations given by de Vries and van Dalen for anodic stripping voltammetry on a stationary mercury film electrode and by Bakanov et al. for a rotating mercury film electrode.     

新型聚N，N-二甲基苯胺/多壁碳纳米管修饰电极的制备、表征与应用

采用多壁碳纳米管(MWNT)改性聚N,N-二甲基苯胺(PDMA)膜,制备了新型复合膜修饰玻碳电极,并用SEM、电化学方法对修饰电极进行表征。 结果表明,无论MWNT是以掺杂还是先滴涂MWNT再聚合DMA多层修饰方式,均会改变PDMA膜的形貌和电化学性能。 复合膜修饰电极比单一PDMA膜修饰电极大幅度提高了比表面积和电活化面积,同时使PDMA和MWNT更好地协同发挥其优良的电化学特性。 实验结果表明,层层修饰制备的聚N,N-二甲基苯胺/多壁碳纳米管复合膜修饰电极对香草醛的电化学响应远大于基体电极和其它方法制备的修饰电极,电催化作用显著提高,其过电位降低了148 mV,氧化峰电流约增加了6倍;其电极反应是吸附控制的不可逆氧化过程,转移电子数n为2,质子数m为1,传递系数α为0.4062,吸附量为Γ=3.527×10-9 mol/cm2;检出下限为8.0×10-7 mol/L,样品平均回收率为99.87%。     

Influence of Nafion Coatings and Surfactant on the Stripping Voltammetry of Heavy Metals at Bismuth‐Film Modified Carbon Film Electrodes

Nafion polymer coated bismuth‐film‐modified carbon film electrodes have been investigated for reducing the influence of contaminants such as surfactants in the anodic stripping voltammetry of trace metal ions. The influence of the coating on electrode response has been tested with both ex situ and in situ bismuth film deposition, with and without the polymer coating. The electrode assemblies and interfacial characteristics in the presence of the non‐ionic surfactant Triton‐X‐100 have been probed with electrochemical impedance spectroscopy. The Nafion coating successfully decreases the adsorption of Triton on the bismuth film surface, and demonstrates that this strategy allows measurement of these trace metals in environmental samples containing surfactants.     

Electrodeposition of mercury film on electrodes modified with clay minerals

A new type of carbon paste electrode modified with clay mineral and covered with a mercury film is presented in this work. Electrodeposition of the mercury film was performed on the carbon paste electrode modified with montmorillonite. The mercury film was deposited by both electrodeposition in situ and a preliminary electrodeposition. The pre-deposited film of mercury showed to be suitable for anodic stripping voltammetry. An open-circuit sorption of Cd, Pb, and Cu with subsequent anodic stripping voltammetry exhibited higher current responses of metals. Besides the enhanced sensitivity superior separation of the current responses during a simultaneous stripping of metals is expected to be achieved by means of the newly prepared electrode. Presented at the 57th Congress of Chemical Societies, Tatranské Matliare, 4–8 September 2005.