电化学表面等离子体共振技术

电化学表面等离子体共振(electrochemical surface plasmon resonance, ESPR)技术是近年发展起来的、将表面等离子体共振技术与电化学方法联用的一种新方法.本文在阐明ESPR基本原理及其主要联用方法的基础上,对ESPR技术在金属离子定性/定量分析、纳米薄膜原位动力学研究、电化学聚合反应过程研究、ESPR生物传感等方面的应用进行了详细评述,并提出了提高ESPR检测灵敏度、ESPR与其他技术的联用以及测量装置的微型化、自动化是今后ESPR技术的发展方向.     

电化学表面等离子体共振技术

电化学表面等离子体共振(electrochemical surface plasmon resonance, ESPR)技术是近年发展起来的、将表面等离子体共振技术与电化学方法联用的一种新方法.本文在阐明ESPR基本原理及其主要联用方法的基础上,对ESPR技术在金属离子定性/定量分析、纳米薄膜原位动力学研究、电化学聚合反应过程研究、ESPR生物传感等方面的应用进行了详细评述,并提出了提高ESPR检测灵敏度、ESPR与其他技术的联用以及测量装置的微型化、自动化是今后ESPR技术的发展方向.     

表面等离子体共振光谱技术与电化学方法联用及其应用

表面等离子体共振（Surface Plasmon Resonance,SPR）技术是利用金属薄膜光学耦合产生的物理光学现象建立的一种非常灵敏的光学分析手段. 近年发展的电化学表面等离子体共振（Electrochemical Surface Plasmon Resonance,EC-SPR）是将时间分辨表面等离子体共振光谱技术与电化学方法联用的一种新技术. 本文介绍了SPR和EC-SPR的基本原理,并重点阐述了时间分辨SPR光谱技术与电化学方法联用及应用,该技术已广泛地应用于反应动态过程研究、生物化学传感器、电极/溶液界面的表征、动力学常数的测定以及生物分子相互作用等领域.     

表面等离子体波共振与常规检测技术的联用

表面等离子体波共振(SPR)是被入射电磁波所激发、存在于金属和电介质界面上电荷密度振动的谐振波.SPR是一种消逝场光学成功应用的典范,它具有体积小、分辨率高、无需标记、抗电磁干扰能力强等特点.本文介绍了SPR与电化学方法(循环伏安法、溶出伏安法)、光学方法(荧光光谱、红外光谱)、质谱和石英晶体微天平等其它常规检测技术联用的研究进展,与其它常规方法联用能进一步提高分析能力,可弥补彼此的不足.本文还特别详细说明了部分电化学方法、干涉测量法与表面等离子体波共振联用的优势及不足.     

表面等离子体共振技术在电化学反应过程研究中的应用

简述了表面等离子体共振(SPR)的基本原理,并综述了表面等离子体共振技术在电化学反应过程中的应用。SPR技术可以无需任何标记原位实时地检测分子间的相互作用,也可用于连续监测吸附/脱附和缔合/解离过程。表面等离子共振光谱(SPRS)与电化学技术结合可用来同时表征和处理电极/溶液的界面,在电化学掺杂/去掺杂过程、吸附/脱附反应的研究、痕量物质的检测、薄膜厚度、介电常数的测定等方面的应用已取得了很大的进展。     

电化学联用表面等离子体共振光谱法对苯胺电化学聚合过程的研究

采用双光电池传感器作为检测器件,设计并构建了新型表面等离子体共振( SPR)光谱仪,在一定范围内实现了SPR角度的快速测量。将此SPR光谱仪与电化学工作站联用,构建了电化学联用-时间分辨SPR ( EC-TR-SPR)光谱仪,以聚苯胺电化学制备过程为研究体系,验证了此EC-TR-SPR光谱仪的特性。同时通过对聚苯胺膜的暂态电化学方法测试(计时电流法和差分脉冲法),考察了仪器的时间分辨能力及其响应速度,验证了此仪器系统在小分子反应动力学以及稳态和暂态电化学联用方法研究中的应用价值。实验结果表明,此SPR光谱仪具有高的时间分辨能力,其时间分辨率可达0.1 ms;对聚苯胺膜的暂态电化学测试结果表明,此联用技术可实时监测SO2-4在聚苯胺膜中的掺杂和去掺杂过程,而单纯的电化学电流-时间曲线无法区分。     

流动注射-电化学-表面等离子体激元共振联用技术研究二茂铁硫醇氧化还原结构变化

采用流动注射-电化学-表面等离子体激元共振联用技术研究了11-二茂铁基十一烷基-1-硫醇自组装膜在氧化还原过程中的构型变化.结果表明,二茂铁硫醇在氧化过程中,分子发生了两种结构变化:远离电极表面,烷基链与电极表面的夹角增大;分子上两个平行的戊基环绕着二茂铁-碳轴发生旋转.     

表面等离子体共振技术在蛋白质-蛋白质相互作用研究中的应用

表面等离子共振(SPR)近年来迅速发展为用于分析生物分子相互作用的一项技术.该技术无需标记、特异性强、灵敏度高、样品用量小,可实现在线连续实时检测.目前SPR已被广泛应用于免疫学、蛋白质组学、药物筛选、细胞信号转导、受体/配体垂钓等领域.该文阐述了基于表面等离子体共振技术生物传感器的基本原理和技术流程,综述了SPR在蛋白质-蛋白质相互作用动力学研究、蛋白质结构及功能研究、蛋白质突变和碎片分析、信号转导中的应用以及SPR在蛋白质-蛋白质相互作用研究中的多项关键技术.指出SPR通过与光谱、电化学等多技术联用后,可以获得更加详实的信息.     

表面等离子体共振传感技术和生物分析仪

表面等离子体共振（surface plasmon resonance, SPR）传感技术是生物化学分析领域常用的分析手段和研究工具,与其相关的研究不计其数,发展日新月异。本研究小组从事SPR传感技术研究近十年,从初期的理论研究、仿真计算、传感器设计以及全自动SPR生物分析仪开发与应用研究,到目前的传感器性能提高、应用拓展,时刻关注着该项技术的最新动态。本文系统综述了SPR传感技术和生物分析仪的原理、结构以及主要功能模块,SPR传感器的调制类型、耦合方式以及SPR成像传感器;介绍了结合局域表面等离子体共振（local surface plasmon resonance, LSPR）技术、改进金属膜系设计、优化数据处理算法等提高SPR生物分析仪性能的方法;阐述了SPR传感技术和生物分析仪的最新进展,包括SPR技术和微流控芯片、电化学技术、表面增强拉曼散射技术（SERS）的联用;列举了SPR生物分析仪在临床诊断、药物筛选、生物分子研究、食品安全和环境监测等领域的应用实例;最后,分析了SPR生物分析仪面临的主要问题以及未来的发展趋势。     

表面等离子体波共振技术应用于气体检测

本文简要介绍了表面等离子体波共振技术的基本原理,重点综述了该技术在气体检测研究中的应用。被检测的气体包括：常见的易燃易爆和有毒气体、有机气体及蒸汽等。通过敏感膜材料的选择和优化、检测装置的改进、制膜方式和工艺条件、薄膜厚度的调整,来提高检测结果的灵敏度、选择性、可逆性、响应时间、脱附时间和重现性等重要参数。将表面等离子体波共振技术和其它技术联用可以在提高检测灵敏度的同时,实现对气体的远程监测。 主要介绍了此技术和光纤技术的联用,此外还讨论了环境特别是湿度和温度对检测结果的影响。     

Electrochemical surface plasmon resonance studies on the deposition of the charge-transfer complex from electrooxidation of o-tolidine and effects of dermatan sulfate

The electrochemical surface plasmon resonance (ESPR) technique was used to investigate the electrodeposition of the charge-transfer complex (CTC) generated during electrooxidation of o-tolidine (o-TD) in pH 4.5 Britton–Robinson buffers and the effects of coexisting dermatan sulfate (DS). The peak-type surface plasmon resonance (SPR) responses (versus time) observed in the cyclic voltammetric experiments indicated the precipitation and dissolution of a poorly soluble CTC, an oxidation intermediate, formed during the redox switching of o-TD in a weakly acidic medium. The effects of potential scan rate and solution pH were examined. The height of the peak-type SPR response to the redox switching of the o-TD/CTC “couple” was notably enhanced by the introduction of DS, due to the formation of a mass-enhanced CTC-DS adduct, as also supported by UV–vis spectroelectrochemistry. The SPR signal responded linearly to the DS concentration up to 14 μmol L⁻¹, with a limit of detection (LOD) down to 8 nmol L⁻¹ (S/N = 3). The analytical performance of the ESPR technique was found to be better than that of the quartz crystal microbalance technique with an LOD value of 70 nmol L⁻¹. The CTC-based ESPR assay is recommended as a new, highly sensitive and dynamically surface-regenerated biosensing technology for other species.     

In situ studies of protein adsorptions on poly(pyrrole-co-pyrrole propylic acid) film by electrochemical surface plasmon resonance

Poly(pyrrole-co-pyrrole propylic acid) (PPy/PPa) composite films were prepared for the first time by electrochemical copolymerization in mixed pyrrole propylic acid (Pa) and pyrrole solutions. The electrochemical growth process was investigated by in situ electrochemical surface plasmon resonance (ESPR). Atomic force microscopy and Fourier transform infrared spectroscopy were applied to characterize the prepared films. Using bovine serum albumin as a model protein, the adsorption kinetics of the protein on PPy/PPa films were studied in situ by SPR. The composition of Pa, the isoelectric point of proteins, the pH of buffers, and surfactant treatment showed dramatic effects on the protein adsorption on the PPy/PPa film. Experimental results indicated that the electrostatic interaction between the PPy/PPa film and proteins plays a critical role in protein adsorption and provided a novel strategy to efficiently immobilize proteins and to reduce nonspecific bindings of proteins in an immunobiosensor.     

Electrochemical surface plasmon resonance investigation of dodecyl sulfate adsorption to electroactive self-assembled monolayers via ion-pairing interactions

The redox-induced assembly of amphiphilic molecules and macromolecules at electrode surfaces is a potentially attractive means of electrochemically modulating the organization of materials and nanostructures on solid substrates via ion-pairing interactions or charge-transfer complexation. In this regard, we have investigated the potential-induced adsorption and aggregation of dodecyl sulfate, a common anionic surfactant, at a ferrocenylundecanethiolate (FcC11SAu) self-assembled monolayer (SAM)/aqueous solution interface by electrochemical surface plasmon resonance (ESPR) spectroscopy. The surfactant anions adsorb onto the electroactive SAM by specific ion-pairing interactions with the oxidized ferricinium species. The ferricinium charge density (QFc+) obtained by cyclic voltammetry and surface coverage measured by SPR indicate that the dodecyl sulfate forms an interdigitated monolayer, where half of the surfactant molecules have their sulfate headgroups paired to the surface and half have their headgroups exposed to the aqueous solution. The surface coverage of dodecyl sulfate was found to depend on both the ferricinium surface concentration and the surfactant aggregation state in solution. A maximum coverage of dodecyl sulfate on the ferricinium surface is obtained below the critical micelle concentration (cmc), in contrast to dodecyl sulfate adsorption to SAM surfaces of static positive charge. This marked difference in adsorption behavior is attributed to the dynamic generation of ferricinium by potential cycling and the specific nature of the ion-pairing interactions versus pure electrostatic ones. The results presented point to a new way of organizing molecules via electrical stimulus.     

Immobilization of laccase on gold, silver and indium tin oxide by zirconium-phosphonate-carboxylate (ZPC) coordination chemistry

In this paper we present a simple method allowing for stable laccase immobilization on various conducting surfaces that retains the activity of the enzyme. The strategy for laccase immobilization presented in this paper relies on Zr(4+) ion coordination chemistry that involves -COO- terminal groups present on the protein. Using a host of techniques, including surface plasmon resonance (SPR), quartz crystal microbalance (QCM) gravimetry, atomic force microscopy (AFM), surface enhanced Raman scattering (SERS), resonance Raman scattering (RR) and electrochemical techniques, we show that laccase bound to a surface coordinatively through zirconium phosphonate/carboxylate (ZPC) functionalities forms a stable enzymatic layer with the enzyme retaining its activity to a significant extent.     

Probing photoelectrochemical processes in Au-CdS nanoparticle arrays by surface plasmon resonance: application for the detection of acetylcholine esterase inhibitors

The photoelectrochemical charging of Au-nanoparticles (NP) in a Au-nanoparticle/CdS-nanoparticle array assembled on a Au-coated glass surface is followed by means of surface plasmon resonance (SPR) spectroscopy upon continuous irradiation of the sample. The charging of the Au-NPs results in the enhanced coupling between the localized surface plasmon of the Au-NP and the surface plasmon of the bulk surface, leading to a shift in the plasmon angle. The charging effect of the Au-NPs is supported by concomitant electrochemical experiments in the dark. Analysis of the results indicates that ca. 4.2 electrons are associated with each Au-nanoparticle under steady-state irradiation. The photoelectrochemical charging effect of the Au-NPs in the Au-CdS NP array is employed to develop a SPR sensor for acetylcholine esterase inhibitors.     

An indium tin oxide electrode modified with gold nanorods for use in potential-controlled surface plasmon resonance studies

The modification of electrodes with gold nanoparticles results in an increased electrode surface area, enhanced mass transport, and improved catalytic properties. We have extended this approach to indium tin oxide (ITO) electrodes to obtain optically transparent gold nanorod-modified electrodes which display enhanced electrochemical capabilities and have the additional advantage of showing a tunable surface plasmon resonance. The procedures for attaining high surface coverage (15 gold nanorods per square µm) of such electrodes were optimized, and the potential-dependent surface plasmon resonance was studied under controlled electrical potential. In an exemplary sensor application, we demonstrate the detection of mercury via potential-dependent formation of an Au-Hg amalgam.

A review on novel developments and applications of immunosensors in food analysis

The present review deals with novel developments in immunosensors destined for final application in food analysis. In this perspective particular emphasis will be given to the most important approaches which recently have been used for immunosensor construction and assembling. For this reason, electrochemical, surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) techniques will be explored in detail and recent and practical examples on food matrices will be reviewed. Objective of this survey is to give a general overview of the possible application of immunosensors to the food analysis field.