扩散性抑制及缺血过程中Ca^(2+)与谷氨酸的同时在体电化学分析

Simultaneous Determination of Glutamate and Calcium Ion in Rat Brain during Spreading Depression and Ischemia Processes

脑神经化学分析是探索大脑功能的重要手段,脑功能的实现依赖于多种化学物质同时发挥作用,单纯一种化学物质的检测难以阐明脑化学信号的传递以及疾病的发生,因此,多物质同时分析尤为重要。本研究通过构建一种双功能电化学生物传感器,实现了谷氨酸和Ca^(2+)同时测定分析。将谷氨酸氧化酶(Glu Ox)和铂纳米颗粒(Pt NPs)共改性的铂丝微电极(Pt ME)作为电流型谷氨酸测定电极,电位响应的全固态钙离子选择性电极(Ca-ISME)用于Ca^(2+)的测定,构建了双功能微电极(DFME)生物传感器,两种信号之间没有串扰,因此可用于谷氨酸和Ca^(2+)的同时监测。DFME生物传感器显示出良好的选择性和低的检出限(谷氨酸为0.5μmol/L,Ca^(2+)为1μmol/L),可满足活体检测需求,并成功用于监测扩散性抑制(SD)及缺血过程鼠脑中谷氨酸和Ca^(2+)的实时变化分析。本研究为体内多种物质的同时检测提供了一种简便有效的方法,为理解脑生理病理过程提供了分子基础。

In vivo chemical analysis is an important aspect in exploring brain functions.Brain function realization depends on multiple chemical substances working together.Sole chemical detection is difficult to clarify the chemical signal transmission and disease occurrence.Thus,it is particularly important to simultaneous determination of multiple biological species in the brain.In this study,we designed and constructed a dual-functional electrochemical biosensor for simultaneous determination of glutamate and Ca^2+.The co-modified Pt-microelectrode of GluOx and Pt NPs was served as amperometric glutamate microelectrode.By incorporating with potentiometric all-solid-state Ca-ISME,the dual function microelectrode(DFME)biosensor was developed for simultaneous monitoring glutamate and Ca^2+ without crosstalk between the two signals.The DFME biosensor showed good selectivity towards common interferences,as well as low detection limits(0.5μmol/L for glutamate and 1μmol/L for Ca^2+),which met the needs of in vivo analysis.The developed biosensor was successfully applied to real-time monitoring of glutamate and Ca^2+ in live rat brain during spreading depression(SD)and ischemia processes.This study provided a simple and effective approach for in vivo analysis of two or more chemical substances,which was helpful for understanding of brain physiological and pathological processes.