电泳沉积法制备重氮功能化石墨烯及其生物传感特性研究

石墨烯材料因其超高的比表面积、优异的导电率和良好的生物兼容性而被广泛应用在电化学生物传感体系中。运用溶液沉积技术制备的石墨烯涂层电极往往由于覆盖性差、均匀度低、附着力弱等问题而使其传感特性受到限制。本项目拟采用简单易行的电泳沉积技术，实现氧化石墨烯和芳基重氮盐离子在电极基片上的同步还原，同时将含有硼羟基、羧基、炔基的芳基基团通过共价连接方式修饰在石墨烯的sp2晶格上，制备出功能化基团修饰的石墨烯电极材料。因而可以构建适用于低碱性电解质条件下的苯硼酸基无酶葡萄糖检测体系，或通过酰胺化反应/“点击”化学法固载筛选后的溶菌酶适体构建无标记超灵敏溶菌酶适体传感器，并应用于临床血清样品中溶菌酶的检测。通过优化电泳沉积条件，本项目可实现功能化石墨烯材料的微观构型及组分调控，全面优化电极体系的电化学传感性能，为开发灵敏度高、准确度好、稳定性强、适用范围广的新型生物传感器奠定重要的临床应用和理论基础。

Graphene-based materials have been widely used in electrochemical biosensing applications due to its high surface area, extraordinary conductivity and good biocompatibility. In the process of electrode coating with graphene-based materials, solution-based techniques are usually applied. However, the deposited films always suffer from ill-defined coverage, poor homogeneity and weak adhesion, leading to unsatisfactory sensing performance. In this project, we propose the use of a facile electrophoretic deposition technique for the deposition of reduced graphene oxide (rGO) with aryl diazonium compounds, in which process graphene oxide (GO) gets reduced with spontaneous surface modification of aryl radicals with B-(OH)2, COOH and alkynyl groups through covalent sp2 bonding by the reduction of diazonium salts in the meantime. After modification, the interfaces are of high interest for designing highly sensitive sensing platforms. rGO modified with boronic acid groups could be applied for non-enzymatic glucose sensing under weak alkaline conditions. While carboxyl and alkynyl terminated interfaces could be used for the construction of lysozyme aptasensor after aptamer immobilization through EDC/NHS coupling or “Click” reaction. Highly sensitive detection of lysozyme in serum will be achieved in direct approach without labeling. By varying the deposition parameters, functionalized rGO matrices with adjustable nanostructure and constitution can be achieved in a straightforward way. The sensing performance of established sensing platforms will also be strengthened. The study will find its wide application in experimental and theoretical domain in developing biosensors with high sensitivity, good reliability, strong stability and wide feasibility.