超微电极技术的发展现状

本文在阐述超微电极技术相关原理的基础上,总结了超微电极的特点、类型及研究方法,综述近十年来超微电极的制备与应用进展,并介绍了超微电极的发展现状。     

纳米级超微电极的研究（Ⅰ）—超微带电极的研制,表征及应用

报道了纳米级超微带电极的制作方法,并分别用扫描隧道电镜、扫描电镜和光电子能谱对电极表面进行表征、用循环伏安法、计时电流法考察了电极的性能、将半微柱的扩散模型用于描述50nm以上的超微带电极,结果表明,超微带电极的带宽对电流变化影响不大,而非法拉第电流却正比于电极面积.用超微带电极可提高信噪比,测定亚铁氰化钾检测限可达5.0×10~(-7)mol/L.     

微纳加工技术在超微电极制备中的应用

从电极材料、绝缘材料、薄膜的图形化等方面,评述了微纳加工技术在单超微电极和超微电极阵列制备中的应用。在单超微电极的制备中,随着微纳加工技术的引入,可以实现具有规则几何形状和微小电极尖端的单超微电极的重复性制备。     

纳米超微电极的研究（Ⅳ）—超微金柱电极的制作与表征

纳米超微电极的研究（Ⅳ）──超微金柱电极的制作与表征张学记，万其进，张悟铭，周性尧（武汉大学化学系，武汉，４３００７２）关键词微电极，纳米超微电极，伏安法，离子束，金纤维最近，纳米超微电极［１～５］的研制成功，使超微电极的研究进入一个新阶段，给电化学...     

超微电极的新进展

超微电极是当前电化学前沿领域和研究热点之一。本文主要介绍了超微电极的基本原理、种类和特点 ,并结合国际上超微电极的最新研究现状 ,介绍了超微修饰电极的特点及其在电分析化学中的应用 ;超微电极在扫描探针显微学、固态电化学、生物细胞体内检测和分析化学等方面中的应用。     

超微电极上半微分电分析法

介绍了超微半球电极上具有简单反应时的半微分循环伏安理论。理论表明,超微电极上半微分电流与电活性物质的浓度成正比,并据此提出了一种利用超微半球电极上半微分曲线进行电化学分析测量的新方法。该法具有灵敏度高、分辨率好等特点。     

超微电极实验:基本原理、制备方法和伏安性能

超微电极的电极尺寸小，双电层电容小，IR降小，传质速率快，响应快，信噪比高，兼具时间和空间分辨率，不仅可以研究快速电极反应动力学性质，而且可以作为电化学扫描显微镜探针，实现基底反应活性的成像，在电化学各个领域均有重要应用，成为一种重要的电化学实验方法。本文将扼要介绍超微电极的基本原理、简易的制备方法及伏安性能的表征实验，以期对开展超微电极实验研究的电化学工作者有所裨益。     

计算机化的多功能超微电极电化学仪器

报道了一种计算机化的多功能超微电极电化学仪器.它具有12种基本功能和正确的电流、电位性质及很高的灵敏度.能用于超微电极的电化学研究和测试,也适用于常规电极.     

超微电极制备技术及材料研究进展

综述了超微电极电化学以及超微电极的制备方法和材料研究进展。重点介绍了自组装技术、模板法和新的刻蚀手段等技术在超微电极制备中的应用,从电极材料和包覆材料两方面对材料的研究进展情况予以说明,并对未来超微电极的发展趋势进行了展望。     

基于超微电极的原位电化学拉曼光谱

原位电化学拉曼光谱是一种重要的光谱电化学技术.基于超微电极的原位电化学拉曼光谱将拉曼光谱反映的结构信息与电极表面的电化学过程从实验上严格对应和关联,为深刻理解电化学反应机理提供依据.本文综述了采用超微电极作为工作电极的原位电化学拉曼光谱的研究方法和应用进展,总结了应用超微电极作为工作电极开展电化学拉曼光谱实验的方法和具有表面增强拉曼活性的超微电极制备方法,展示了如何利用在超微电极表面获得的拉曼光谱与界面电化学过程的严格关联研究单个锌颗粒电化学氧化过程、吡啶分子在Au电极表面的电化学吸附过程,以及如何利用该技术能以高的信噪比和灵敏度同时测量光电流与分子反应这一特性研究对巯基苯胺选择性光氧化反应.采用超微电极作为工作电极的原位电化学拉曼光谱技术极大拓展了拉曼光谱技术的研究范围,有望成为探索(光)电化学反应的有力工具.     

单个Nafion@Ru和Au-Nafion@Ru纳米粒子的电化学和电化学发光碰撞行为研究

通过静电作用在Nafion和Au-Nafion纳米粒子(NPs)上负载钌联吡啶(Ru(bpy)32+)分别制得Nafion@Ru和Au-Nafion@Ru NPs.分析并比较了Au-Nafion@Ru和Nafion@Ru NPs在金超微电极(Au UME)上随机碰撞产生电流响应峰的平均峰大小、峰电量和单峰持续时间,建立...     

Single Potential Scan Methods for Nanoporous Gold Formation on Ultramicroelectrode Surfaces

Nanoporous gold (NPG) has been extensively investigated because of their applications. Here, we report a straightforward method for the preparation of NPG on micrometer-scale electrodes. Well-defined NPG structures were formed on Au surfaces by a single potential scan within 100 seconds. This method is applied to Au surfaces with small dimensions regardless of the electrode geometry, whereas it is not applicable to conventional millimeter-scale electrodes. The effects of electrode sizes and scan rates on NPG formation were systematically examined, and the amperometric glucose detection with 20-μL sample volumes using an ultramicroelectrode (UME) with NPG surfaces was demonstrated.     

Combined Blip and Staircase Response of Ascorbic Acid‐Stabilized Copper Single Nanoparticle Collision by Electrocatalytic Glucose Oxidation

The current response of the collision of ascorbic acid‐stabilized copper (Cu) single nanoparticles (NPs) on a gold (Au) ultramicroelectrode (UME) surface was observed by using an electrocatalytic amplification method. Here, the glucose oxidation electrocatalyzed by oxidized Cu NPs was used as the indicating reaction. In this system, the NP collision signals were obtained simultaneously by both direct particle electrolysis and electrocatalytic amplification. For example, when the applied potential was high enough for Cu NP oxidation, a blip response combined with a staircase response was observed as a current signal. The blip part in the single Cu NP collision signal indicates the self‐oxidation of a Cu NP, and the staircase part indicates the steady‐state electrocatalytic reaction by oxidized Cu NP.     

Highly Sensitive Neurotransmitters Analysis at Platinum‐Ultramicroelectrodes Arrays

An easy way to determine norepinephrine (NE) in biological fluid using a platinum ultramicroelectrode array (Pt‐UMEAs) is described. Issues related to UME electrode surface treatment and characterizations are also addressed. At optimized experimental conditions the dynamic concentration range was 1.0 to 10.0 µmol L^?1 with a detection limit of 40.5 nmol L^?1. The repeatability of current responses for injections of 5 µmol L^?1 NE was evaluated to be 4.0 % (n=10). This approach obtained excellent sensitivity, a reliable calibration profile and stable electrochemical response for norepinephrine detection. The content of NE in urine samples without any preconcentration, purification, or pretreatment step, was successfully analyzed by the standard addition method using the Pt‐UMEAs.     

结合光学成像技术研究单颗粒碰撞电化学

近年来,单颗粒碰撞技术在纳米电化学领域受到广泛关注. 该技术通常控制超微电极处于某一电位,检测单个纳米颗粒随机碰撞到电极表面后产生的瞬时电流. 通过分析电流信号,可以研究单个纳米颗粒的性质. 尽管该技术可以检测单个纳米颗粒的电化学或电催化电流,但是传统的单颗粒碰撞技术缺乏空间分辨率,难以识别和表征特定的纳米颗粒. 因此,结合光学成像技术研究单颗粒碰撞电化学来补充电化学技术缺失的空间信息已成为一种趋势. 本文首先简要综述了单颗粒碰撞技术的三种检测原理,主要介绍了近年来单颗粒碰撞技术与荧光显微镜、表面等离激元共振显微镜、全息显微镜和电致化学发光相结合的研究进展,最后展望了单颗粒碰撞技术未来的发展趋势.     

Surface interrogation mode of scanning electrochemical microscopy for oxidation study of adsorbed CO generated from serine on platinum

We report a new method for detection and oxidation of adsorbed carbon monoxide(CO_（ads）) generated from serine on a polycrystalline platinum ultramicroelectrode（UME） by bromine（Br₂） using in situ surface interrogation（SI） mode of scanning electrochemical microscopy（SECM）.In the SI mode,tip and substrate are both Pt UMEs,and CO_（ads） on Pt substrate,generated from serine,can be oxidized by the tip-generated Br₂ giving a positive response.Dosing CO_（ads） from serine instead of purging CO gas expands the newly introduced reaction of Br₂ with CO_（ads） and further enhances the hope to get rid of CO_（ads） on Pt for fuel cells.     

Mathematical Modelling of the Influence of Ultra‐micro Electrode Geometry on Approach Curves Registered by Scanning Electrochemical Microscopy

Scanning electrochemical microscopy (SECM) is an emerging electroanalytical sensing technique, used to investigate the electrochemical properties of the sample by ultra‐micro‐electrode(UME) scanning probe. UME signal usually is the current, which depends not only on the properties of the evaluated system but also on UME characteristics such as geometry. Variations of UME geometry can decrease accuracy of the measurement, and then correct analysis of the SECM data becomes almost impossible. In the present work, we studied the precision of measurements with three different the most frequent types of defected UME's ((i) recessed‐UME, (ii) outwarded‐UME, (iii) cone‐UME). Measurement results were compared with that obtained with not defected standard‐plane‐UME. Computational experiment was performed with SECM model using diffusion equations with non‐rectangular border conditions to calculate estimated currents for these three types of defected UMEs and to compare them with that for standard‐plane‐UME. In order to test the correctness of the model, computations for recessed‐UME model were compared with data of real‐recessed‐UME experiment.     

Observation of Single Pt Nanoparticle Collisions: Enhanced Electrocatalytic Activity on a Pd Ultramicroelectrode

Single Pt nanoparticle (NP) collisions on an electrode surface were detected by using an electrocatalytic amplification method with a Pd ultramicroelectrode (UME). Pd is not a preferred material for UMEs for the detection of single Pt NP collisions, because Pd shows similar electrocatalytic activity compared with Pt for hydrazine oxidation, thus resulting in a high background current level. However, a Pt NP colliding on the Pd UME shows greatly enhanced activity compared with a Pt NP on an inert UME, such as a Au UME, which is usually used for the detection of single Pt NP collisions. The use of an electroactive UME material instead of an inert one facilitated the study of single‐NP activity on the various solid supports, which is important in many NP applications.     

Fabrication of Prussian Blue modified ultramicroelectrode for GOD imaging using scanning electrochemical microscopy

A Prussian Blue (PB) film modified disk ultramicroelectrode (UME) was fabricated by electrochemical deposition technique on a Pt-disk UME. The electrocatalytical reductions of hydrogen peroxide derived from glucose oxidase (GOD) on this modified UME were investigated. The enzymatic biochemical reactivity was imaged by scanning electrochemical microscopy (SECM) utilizing the PB film modified UME. It is evident that sensitivity and spatial resolution for hydrogen peroxide measurement were improved obviously. SECM images obtained clearly revealed the concentration profile of the reaction products around the enzymes. The PB film modified microelectrode is in the nature of simple preparation, high catalytic activity on hydrogen peroxide and substrate selectivity for SECM etc.