基于热控电极的电致化学发光传感器的研究进展

Recent Progress of Electrochemiluminescence Sensors Based on Electrically Heated Electrode

电致化学发光(ECL)检测技术因其具有无需激发光源、仪器简单、灵敏度高、选择性好等特点,被广泛应用于环境分析、生物分析等领域.温度是影响ECL的主要因素之一,在传统的ECL传感器中大多是通过溶液整体加热的方法来控制温度,这种方法操作繁琐,且溶液中的热不稳定性物质及易挥发性物质容易受到影响,因此电极很少工作在最适宜的温度下.热控电极技术可以只提高电极表面温度,而维持溶液的整体温度不变,使用起来具有很好的便利性.作者课题组首次将热控电极引入到ECL传感器的构建中,由于电极表面和溶液之间存在一定的温度梯度,因此可以引发强制对流,从而加快物质的扩散和对流速率;电极表面温度的升高还可以进一步提高电极表面物质的电化学反应速率,这两方面的共同作用提高了ECL检测的灵敏度.同时,利用热控电极可以解决整体加热所引起的背景信号升高,挥发性、热不稳定性物质易受温度影响等问题,而且通过电极加热的方法可去除电极表面的污染物,从而提高ECL检测的重现性.本文综述了近年来基于热控电极技术的ECL传感器的研究进展,主要介绍了热控电极的加热方式、电极种类以及热控电极在ECL中的应用等,并分析了该技术在实际应用中面临的主要问题,对该技术未来的发展趋势进行了展望.

Electrochemiluminescence(ECL) has broad application in the fields of environmental monitoring and biological analysis due to its intrinsic advantages such as excellent versatility, good detection sensitivity, and high specificity. The intensity of ECL can be influenced by temperature variation in the ECL quantum efficiency and the rate of electrochemical reaction. However, traditional temperature control is commonly realized through bulk solutions heating, which is complicated and unfavorable for detection when the volatile and thermally unstable materials existed. In order to address these problems, electrically heated electrodes are used to adjust the temperature desired. The major character of this technique lies in the heating electrode up, while leaving the bulk solution at ambient temperature, which promotes the performance of the sensor by affecting the thermodynamic and kinetic parameters of the reaction, and further improves the sensitivity of the ECL detection. Moreover, the background signal, and the volatile and thermally unstable substances that are susceptible to temperature will not be affected. The contamination on the surface of the electrode can also be easily removed by electrical heating, thereby the reproducibility of ECL sensor is improved. As a whole, this article aims at reviewing the research progress of ECL sensors based on the electrically heated electrode in the analysis and detection of target molecules, summing up the main problems in the practical determination, and providing an outlook in the future development trend of this technology.