金在微电极上的电沉积研究

本工作利用微循环伏安法和阶跃电位法研究在ＡｕＣｌ３的酸性溶液中金在玻碳和铂微电极上的电沉积行为。结果表明，金在微电极上成核所需的过电位较高，但成核几率也高，在所研究的微电极尺寸范围内，金可形成大量的临界单核，且核的生长速率很快。铂微电极上金电沉积的Ｉ－ｔ曲线符合连续成核的模式。     

混合香蕉组织碳糊生物微电极的研究及在活体分析中的应用

我们研制了混合香蕉组织碳糊生物微电极,用于神经递质多巴胺(DA)的测定,研究了DA在该电极上的伏安特性及最佳工作条件。该电极选择性好,可抗256倍维生素C(V_(?))的干扰;灵敏度高,检出下限为3.3×10~(-8)mol/L。用于活体分析鼠脑纹状体中DA,线性范围为1.9×10~(-6)～1.3×10~(-4)mol/L(静置时间为10s)。     

硫辛酸修饰碳纤维微电极在抗坏血酸共存下选择性测定神经递质多巴胺

本研究了硫辛酸修饰电化学活化碳纤维电极。此电极在测定脑神经递质多巴胺（ＤＡ）时，具有较高的灵敏度和较好的选择性，它能够有效地消除抗坏血酸（ＡＡ）的干扰。该电极测定多巴胺的线性范围为１×１０＾－８－１×１０＾－５ｍｏｌ／Ｌ；检出下限为５×１０＾－９ｍｏｌ／Ｌ。     

微电极电位溶出法研究进展

本文介绍用于电位溶出分析（ＰＳＡ）的固体微电极的种类及制作，综述了该领域研究的理论进展、技术应用及其方法的优越性，引用文献４１篇     

氢离子选择性液膜超微电极的研制

本报道新的以三－十二烷基胺（ＴＤＤＡ）为载体和以对氯苯硼四－十二铵（ＥＴＨ２１９１）为载体的ｐＨ微电极膜，与原有的ＴＤＤＡ膜相比较，新的ＴＤＤＡ膜和ＥＴＨ２１９１膜制备更加容易，膜内阻从原有的２×１０＾１１Ω（１μｍ）下降到３．５×１０＾１０Ω（１μｍ），其中ＥＴＨ２１９１膜的动力学响应ｐＨ范围为１２～４．５，与原有的ＴＤＤＡ膜（ｐＨ范围为１２～５．５）比较，拓宽了１个ｐＨ，而且ＥＴＨ２１９１膜     

The use of a detectable,mass-spectrometry-cleavable linker for quality control on an addressable microelectrode array

The synthesis, site-selective placement, and TOF-SIMS cleavage properties of a new, fluorescent linker for attaching molecules to a microelectrode array are reported. The linker was developed to provide a handle for quality control assessment of the microelectrode arrays being used to probe the binding of molecular libraries with biological receptors.     

Towards multifunctional microelectrode arrays

A single microelectrode array platform, divided into groups of microelectrodes with flexible multiplexing can enable a 'defective' cluster of microelectrodes to be readily identified, by comparing normalised currents with the numbers of microelectrodes in the groups of arrays. This generic design principle may be extended for integrating multiple analyte sensing in a single microarray platform. The calibration of the microelectrode arrays, using white light interferometry and electrochemistry is described. The application for multianalyte detection is discussed.     

Biosensor on the base of polypyrrole modified ultramicroelectrode arrays

A novel approach for the construction of a micro biosensor on the base of amperometric enzyme microelectrode arrays is described in this paper. The technique contains the electrochemical deposition of different enzymes in a conducting organic polymer, e.g. polypyrrole, on a transducer built up with the help of microfabrication technology. The electrochemical characteristics of these microelectrode arrays can be compared to conventional microelectrodes with the advantage of higher current outputs. For the first time different model enzymes like glucose oxidase, choline oxidase and lactate oxidase have been tested showing the principal possibility to construct a micro biosensor on the base of ultramicroelectrode arrays.     

Voltammetric characterisation of silicon-based microelectrode arrays and their application to mercury-free stripping voltammetry of copper ions

This paper describes the electrochemical characterisation of a range of gold and platinum microelectrode arrays (MEAs) fabricated by standard photolithographic methods. The inter-electrode spacing, geometry, numbers and dimensions of the electrodes in the arrays were found to influence the voltammetric behaviours obtained. Excellent correlation was found between experimental data and theoretical predictions employing published models of microelectrode behaviour. Gold MEAs were evaluated for their applicability to copper determination in a soil extract sample, where agreement was found between the standard analytical method and a method based on underpotential deposition—anodic stripping voltammetry (UPD-ASV) at the MEAs, offering a mercury-free alternative for copper sensing.     

Chemically Modified Electrodes for Recessed Microelectrode Array

Chemical modifications on recessed microelectrode array, achieved via electrodeposition techniques are reported here. Silicon-based gold microelectrode arrays of 10 μm microband and microdisc array were selected and functionalised using sol-gel and nanoporous gold (NPG) respectively. For electrochemically assisted self-assembly (EASA) formati6154on of sol-gel, electrode surface was first pre-treated with a self-assembled partial monolayer of mercaptopropyltrimethoxysilane (MPTMS) before transferring it into the sol containing cetyltrimethyl ammonium bromide (CTAB)/tetraethoxysilane (TEOS):MPTMS (90:10) precursors. A cathodic potential is then applied. It was found that larger current densities were required in ensuring successful film deposition when moving from macro- to micro- dimensions. For NPG modification, a chemical etching process called dealloying was employed. NPG of three different thicknesses have been successfully deposited. All the modified and functionalized microelectrode arrays were characterized by both optical (SEM) and electrochemical analysis (cyclic voltammetry and impedance spectroscopy). An increase in surface area and roughness has been observed and such will benefit for future sensing application.     

Building addressable libraries: The use of a mass spectrometry cleavable linker for monitoring reactions on a microelectrode array

Time-of-flight secondary ion mass spectrometry (TOF SIMS) has been used in conjunction with a mass spectrometry cleavable linker to determine the percent conversion of reactions that were conducted site-selectively on an addressable microelectrode array. When combined with fluorescence techniques for analysis of the reactions, the TOF SIMS experiment provides a means for optimization of both reaction confinement and reaction efficiency on the microelectrode arrays.     

Voltammetric Characterization of Micro‐ and Submicrometer‐Electrode Arrays of Conical Shape for Electroanalytical Use

Densely packed micro‐ and submicrometer electrode arrays of platinum and gold (the nominal number, N, of electrodes in each array varies between 225 and 3600) are fabricated by photolithographic technique and vapor deposition processes of metal films. The electrodes are conical‐shaped and only their apexes are exposed to the electrolytic solution. The electrode arrays are characterized electrochemically in Ru(NH₃)₆Cl₃ aqueous solutions by using cyclic voltammetry at low scan rates, to establish the number of electrochemically active electrodes (N_ac) in each array; the geometric characterization is performed by scanning electron microscopy. All the investigated arrays provide steady‐state voltammograms, indicating diffusionally independent behavior of each microelectrode. The number of microelectrodes that are active in the fabricated arrays depends on microelectrode density. In particular, for the arrays with N=3600 and N=225, the fraction of active sites is about 45% and 90%, respectively. The analytical performance of some of the Pt version of the arrays is tested in hydrogen peroxide solutions, allowing verifying that linear calibration plots over the concentration range (0.1–20 mM) are obtained. This dynamic range is larger than that typically recorded at smooth polycrystalline platinum electrodes (0.5–5 mM), and the better performance is attributed to both the higher aspect ratio of the cone geometry and the higher mass transport associated to each microelectrode of the array. Reproducibility (within 3.5%, r.s.d.) and long‐term stability (within 5%, r.s.d., after 8 h continuous use) of the electrode systems are satisfactory. A low detection limit, based on the signal to noise ratio equal to 3, of 0.05 mM is found, which is adequate for a rapid monitoring of H₂O₂ in real samples and industrial processes.     

Site-selectively functionalizing microelectrode arrays: the use of Cu(I)-catalysts

Site-selective Cu(I)-catalyzed reactions have been developed on microelectrode arrays. The reactions are confined to preselected electrodes on the arrays using oxygen as the confining agent. Conditions initially developed for the Cu(I)-catalyzed click reaction have proven general for the coupling of amine, alcohol, and sulfur nucleophiles to both vinyl and aryl iodides. Differences between reactions run on 1-K arrays and reactions run on 12-K arrays can be attributed to the 1-K array reactions being divided cell electrolyses and the 12-K array reactions being undivided cell electrolyses. Reactions on the 12-K arrays benefit from the use of a non-sugar-derived porous reaction layer for the attachment of substrates to the surface of the electrodes. The reactions are sensitive to the nature of the ligand used for the Cu catalyst.