等离子体聚合法修饰半导体光电极的研究——聚丙烯腈/n-GaAs,n-GaP电极

用导电聚合物修饰光电化学体系中的半导体电极,对于抑制电极的光腐蚀、改善电极特性及赋予其催化功能有明显的效果.在制备聚合物薄膜的几种方法中,等离子体聚合可得到高度交联、均匀、化学稳定性好的超薄膜,且成膜工序简单,已引起重视并取得初步应用。等离子体聚合法修饰导体电极国内外均有报道,但在修饰半导体电极方面的研究甚少。本文探讨了用这种方法在n-GaAs、n-GaP电极上制备聚丙烯腈(PAN)薄膜,并进行     

功能性聚合物薄膜修饰电极

化学修饰电极是当前在电化学、电分析化学方面十分活跃的研究领域。功能性聚合物薄膜由于其特殊的化学结构赋予其许多独特的功能,诸如选择性、分子识别、pH敏感、光化学敏感等;功能性聚合物修饰电极可以赋予电极许多特殊功能,拓展电极的应用范畴,故而备受关注。本文分别从分子印迹聚合物传感器和生物酶传感器制备的角度,综述在电极表面构筑功能性聚合物薄膜的材料以及方法,重点论述电泳沉积技术在电极修饰中的新应用。这些功能性聚合物薄膜在电极表面的构筑方法可以广泛的拓展到其它传感器的制备中,并指导特殊的传感器的制备,具有重要的研究和应用价值。     

聚2,6-吡啶二甲酸膜对儿茶酚和对苯二酚电氧化的催化性能及其应用

研究了２,６－吡啶二甲酸在玻璃电极上的电化学聚合物薄膜修饰电极的电化学特性,发现其对儿茶酚和对苯二酚析电化学氧化具有显著的催化作用,使它们的氧化电位降低,峰电流显著增大。从聚合物膜与多酚化合物的氢键作用对催化机理进行了探讨。该聚合物膜修饰电极可用于多酚的电化学测定。     

磷钼酸掺杂的聚吡咯薄膜电极的表征

对离子在导电聚合物修饰电极中起着很重要的作用．因止匕自从导电聚合物薄膜修饰电极的研究开始以来，A们尝试了在导电聚合物膜中掺杂各种各样的离子［‘一句，以使导电聚合物膜向功能化方向发展．在这些众多的掺杂离子中，人们无感兴趣的是将那些电活性阴离子作对离子掺杂人导电聚合物膜中，如时C叫6【‘，司、杂多酸根离子”河等·将电活性阴离子作为对离子掺杂人导电聚合物膜修饰电极中，有助于人们对这种修饰电极的研究，因为这些对离子可以作为一种探针来检测对离子在腰中的传输情况．杂多酸掺杂的导电聚合物电极还具有电催化性能，对…     

聚5-磺基水杨酸修饰电极上对苯二酚的电化学行为

用循环伏安法将 5 磺基水杨酸修饰于玻碳电极表面 ,制备出对对苯二酚具有电催化作用的聚合物膜修饰电极。研究了对苯二酚 (HQ)在该聚合物薄膜修饰电极上的电化学行为。在 0 5mmol/LH2 SO4底液中 ,HQ在该电极上的线性范围为 2 0× 1 0 - 6～ 1 0× 1 0 - 4 mol/L。该修饰电极可将对苯二酚和邻苯二酚(CC)的氧化峰分开约 1 0 5mV     

聚萘酚类pH修饰电极的研究

聚合物薄膜修饰电极作为pH传感器研究颇多,这些传感器多为苯胺及其衍生物聚合膜电极,而对在有机合成及生物化学中起着重要作用的萘胺及其衍生物的研究较少。本文以铂丝电极为基体,用电化学方法在其上修饰     

多巴胺在聚2,4,6-三甲基吡啶修饰电极上的电化学行为

用循环伏安法制备了聚 2 ,4 ,6 三甲基吡啶修饰玻碳电极 ,研究了神经递质多巴胺在该聚合物薄膜修饰电极上的电化学行为。实验结果表明 :在pH 7.4磷酸盐缓冲溶液中 ,多巴胺在该修饰电极上的线性范围为4 .0× 10 -6～ 1.0× 10 -5mol/L。该修饰电极对抗坏血酸无响应 ,从而可有效消除其对多巴胺测定的干扰     

化学修饰电极的研究ⅩⅢ. 聚乙烯二茂铁(PVFc)薄膜电极和电催化效应

本文研究了影响PVFc薄膜电极伏安性质的各种因素, 讨论了聚合物薄膜电极的电荷传递过程。溶液平衡离子的水合半径大小、离子强度、溶剂对薄膜的溶胀性质以及聚合物薄膜的厚度是影响聚合物薄膜电极伏安性质的主要因素。研究了PVFc薄膜电极对亚铁氰化钾、左旋多巴和儿茶酚的电催化作用, 用旋转园盘电极研究了催化过程动力学。抗坏血酸和儿茶酚的混合物在PVFc薄膜电极上呈现分开的氧化还原峰, 有应用于生物化学分析的意义。     

聚2-吡啶甲酸修饰电极伏安法测定多巴胺

用循环伏安法制备了聚２－吡啶甲酸修饰玻碳电极，研究了神经递质多巴胺（ＤＡ）在该聚合物薄膜修饰电极上的电化学行为。实验结果表明，在ｐＨ７．０的磷酸盐缓冲溶液中，ＤＡ在该电极上的线性范围为１．０×１０－７～１．０×１０－５ｍｏｌ／Ｌ。该修饰电极对抗坏血酸（ＡＡ）无响应，从而可有效消除其对ＤＡ测定的干扰。     

聚噻吩类导电聚合物及其复合膜修饰电极的制备及其在电分析化学中的应用

聚噻吩类导电聚合物修饰电极在电化学检测某些生物分子方面显示出独特的优势,尤其是聚(3-甲基噻吩)(P3MT)修饰电极,这是因为3-甲基噻吩易于电聚合成膜,得到的导电薄膜电导率高、电催化效果好、稳定性高、耐用、抗污染,而且还具有很好的选择性和灵敏性.     

Electrocatalytic oxidation of some biologically important compounds at conducting polymer electrodes modified by metal complexes

Conducting poly(3-methylthiophene) electrodes were electrochemically prepared. The resulting polymer films were modified with an inorganic complex, ferrocene. The incorporation of the ferrocene/ferrocenium moiety into the polymer film resulted in enhanced charge transfer towards the oxidation of some organic molecules of biological interest. The electrochemical response of the complex-containing polymer electrode was compared to that of the unmodified polymer electrode and that of the substrate. Apparent diffusion coefficients of the redox species were estimated from the cyclic voltammetric data for different biological molecules at the ferrocene-containing polymer electrode. Infra-red spectroscopic measurements for the “as-grown” films revealed the presence of the inorganic complex within the polymer. The modified polymer electrode showed noticeable enhancement for the charge transfer across the film interface and can be used as an electrochemical sensor for biological compounds. Received: 3 June 1997 / Accepted: 7 July 1997     

Selective Detection of Dopamine and Its Metabolite,DOPAC, in the Presence of Ascorbic Acid Using Diamond Electrode Modified by the Polymer Film

The surface of boron‐doped diamond (BDD) electrode is modified by the polymer film for the first time. The cationic polymer film of N,N‐dimethylaniline (DMA) is electrochemically deposited on BDD electrode surface. This polymer (PDMA) film‐coated BDD electrode is used as a sensor which selectively detect dopamine (DA) in the presence of ascorbic acid (AA). This electrode also can detect both DA and its metabolite, 3,4‐dihydroxy phenyl acetic acid (DOPAC) in the presence of AA in the range of the physiological concentrations of these species. Favorable ionic interaction (i.e., electrostatic attraction) between the PDMA film and AA or DOPAC lowers their oxidation potentials and enhances the current response for AA and DOPAC compared to that at the bare electrode. The PDMA film also shows a hydrophobic interaction with DA and DOPAC. In cyclic voltammetric measurements, the PDMA film‐coated electrode can successfully separate the oxidation potentials for AA and DA coexisting in the same solution and the separation is about 200 mV. AA oxidizes at more negative potential than DA. In square‐wave voltammetry, the sensitivity of the PDMA film‐coated BDD electrode for DA in the presence of higher concentration of AA is higher than that of the PDMA film‐coated glassy carbon electrode. The hydrodynamic amperometric experiments confirm that the oxidation of AA is not affected by the oxidized product of DA and vice versa. So, unlike the bare electrode the catalytic oxidation of AA by the oxidized DA is eliminated at the PDMA film‐coated BDD electrode. The sensitivities of the modified electrode for AA, DA and DOPAC, which are present in the same solution with their physiological concentration ratios, are calculated to be 0.070, 0.363 and 0.084 μA μM^?1, respectively. The modified electrode exhibits a stable and sensitive response to DA.     

聚藏红T修饰电极的制备及对多巴胺的电催化性能

用循环伏安法在石墨电极和ITO导电玻璃上制备了藏红T聚合物薄膜修饰电极,研究了电聚合过程及循环伏安性质.聚藏红T膜修饰石墨电极在pH 6.81的PBS中循环扫描,有两对氧化还原峰,峰电位分别为Ep,a(P1)=-0.5 V,Ep,c(P1)=-0.575 V,Ep,a(P2)=-0.36 V,Ep,c(P2)=-0.425 V,而且聚合物较稳定.测定了聚藏红T膜的可见光谱性质.实验表明,聚藏红T膜修饰电极对多巴胺有明显的催化作用.     

Electrochemical Biosensing of DNA Immobilized Poly(Vinylferrocenium) Modified Electrode

The polymer, poly(vinylferrocenium) (PVF⁺) modified electrode was developed as the first time herein for the improved electrochemical sensing of DNA based on the oxidation signals of polymer and guanine. The morphologies of polymer film and DNA immobilized polymer film were examined using scanning electron microscope (SEM). The electrochemical behavior of polymer modified electrode was investigated by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in the absence/presence of DNA. Experimental parameters, such as the polymeric film thickness, the DNA immobilization time, the concentration of buffer solution, pH and DNA concentration were examined in order to obtain more sensitive and selective electrochemical signals. After optimization studies, DNA hybridization was also investigated.     

ELECTROCHEMISTRY OF NICKEL(II) TRYPTOPHAN FILM ELECTRODE AND ELECTROCATALYTIC OXIDATION OF METHANOL

A polymer film of tryptophan was obtained at a glassy carbon electrode (GC) by cyclic voltammetry. The cyclic voltammograms of the polymer film electrode(poly-Try GC) exhibited two redox waves. After incorporation of Ni(II), the electrode (poly-Ni(II) Try/GC) was greatly improved in catalytic activity. The potential 0.65 V of methanol oxidation at the poly-Ni(II)Try/GC is much more negative than the potential at the poly-Try/GC and at the bare glassy carbon (GC) electrode in 0.01 mol/L NaOH.     

Carbon Powder Based Films on Traditional Solid Electrodes as an Alternative to Disposable Electrodes

The covering of conventional solid electrode with a film using an ink containing a conductive powder and a polymer enables to broaden the potential window of the original solid electrode. A solid silver amalgam electrode covered with such a film exhibits a potential window from ?600 mV to +1400 mV vs. SCE reference electrode. The renewal of the film is fast and simple: the electrode can be simply wiped with a filter paper to remove the old film and immersed into an ink solution or 1–2 μL of this ink solution can be applied to the surface of the electrode with a micro dispenser to form a new film. Therefore, just the inexpensive film at the electrode surface is disposable and there is no need to dispose the whole, more expensive electrode. Moreover, when a suitable electrochemical pretreatment of the film electrode is applied, the same film can be used for reproducible measurements for several days.     

导电高聚物修饰纳米尺度TiO~2多孔膜电极的光电化学研究

用光电化学方法研究了用导电高聚物修饰的纳米晶TiO~2多孔膜电极在不含氧化还原对和含不同氧化还原对体系电解质溶液中的光电转换过程。TiO~2/导电高聚物多孔膜电极为双层n型半导体结构,内层TiO~2多孔膜的禁带宽度为3.26eV,外层聚吡咯(PPy)膜的禁带宽度为2.23eV,而聚苯胺(PAn)膜的禁带宽度为2.88eV。用导电高聚物修饰半导体电极能使其在可见光区的光吸收增加,光电流增强,且起始波长红移至>600nm,使宽禁带半导体电极的光电转换效率得到明显改善。     

Electrocatalytic oxidation of uric acid at an electrodeposited redox polymer film-modified gold electrode

A hydrated osmium complex-containing redox polymer film-modified gold electrode based on electrochemical cross-linking was developed. The amount and the characteristics of redox polymer film cross-linked on the gold electrode were investigated by using electrochemical quartz crystal microbalance (EQCM). The redox polymer film exhibited a strong electrocatalytic activity toward the oxidation of uric acid with a lowering of the overpotential by about 230 mV and a large increase in the magnitude of the oxidation peak current. Based on this procedure, an amperometric method for the determination of uric acid concentration was proposed.     

Effect of thickness on the capacitive behavior and stability of ultrathin polyaniline for high speed super capacitors

In this work four polyaniline (PANI) film electrode with different thickness were synthesized by electrochemical method on the surface of glassy carbon (GC) electrode. Four polymer films with various thicknesses from 0.5 to 11 μm were synthesized. Electropolymerization occurs in low monomer concentration. Morphology study of electrode shows that surface structure of polymers depends on film thickness. Capacitance of electrode was studied by CV and charge-discharge (CD) methods. Specific capacitance (SC) of electrodes using cyclic voltammetry were calculated 620, 247 F g^–1 for thinnest and thickest polymer film, respectively. Stability of electrodes was studied during 1000 voltammogram cycles. Results show that with the increase of thickness the stability of electrodes enhanced and reach to a maximum and then decreased.