Structure Improvement And Characteristic Study Of Dissolved Oxygen Microelectrode And Glucose Oxidase Microelectrode

Microsensor was firstly an important mean in the studies of biophysical andneural electrophysiological field, and was applied to environmental field since1990s.Since then, microelectrode became a powerful tool for characterization of thecharacteristic parameters’ concentration gradient in microenvironment between solid/liquid interface, which provides an important way of studying the microscopic masstransfer process and reaction dynamics theory of the liquid/solid interface.The rapid development of nanoscience and technology in recent years and itsapplication in micro-electrode field precipitating new types of nano microelectrode.At present, there is few research and analysis of microelectrode technique inenvironment-related issues, and there is great lack of independent research andcommercialization in micro-electrode topics.This study focus on widely used dissolved oxygen microelectrode and itsstructure. After optimize the guard-electrode, the new microelectrode was comparedwith traditional one from different aspects, such as residual current (I0), the linearcorrelation (R2), disturbance effects and resolution and so on. The results showsnewly designed dissolved oxygen microelectrode performance better than traditionalone: residual current reduced by about60%, with a tiny current of about300pA;linear correlation R2is above0.99; the presence of newly designed guard-electrodecan greatly stable the electrical signal, the disturbing effect of output can be reducedto about0.5%from3%to4%; with distinguished resolution below1nA.ZnO Nanorods were deposited on the surface of platinum electrode bylow temperature hydrothermal method, on which glucose oxidase wasimmobilized by electrostatic adsorption, thus nano-ZnO modified glucoseoxidase microelectrode was completed. The response time of thismicroelectrode was less than0.5s, with the lowest detection limit of2mmol/L, and the linear range is4mmol/L to30mmol/L. Linear correlationbetween glucose concentration and response peak current is0.9973. Anotherkind of nano-Au modified glucose oxidase microelectrode was fabricated indifferent mechanism. Gold nanoparticles were deposited by electrochemicaldeposition on the surface of carbon fiber, and glucose oxidase was submitjoint fixed onto. Gold nanoparticle modified glucose oxidase micro-electrode bared a response time less than1s,with the lowest detection limit of1mmol/L,and the linear range of1mmol/L to20mmol/L. The linear correlationbetween glucose concentration and response peak current is0.9471. Finally,two kinds of electrodes were compared and analyzed from the base material,the modified situation, and response to glucose solution and so on, toevaluated the effect of different material and modify choice on thecharacteristics of electrodes.Due to the enormous applications and prospects for development ofsensor technology in various fields, the study of different types ofmocro-electrode of far-reaching significance in the chemical and biologicaldevelopment and application, especially for environmental monitoring aspect,which can be used in the research of degradation kinetics from electron donorand electron acceptor in the same medium.