基于线性范围可调的适配体功能化微电极的鼠脑中钾离子的活体分析

An Aptamer-based Microelectrode with Tunable Linear Range for Monitoring of Kþin the Living Mouse Brain

钾离子(K^(+))广泛参与多种生理病理过程,其异常变化与脑缺血等脑部疾病的发生密切相关。在体内获取K^(+)的变化对了解K^(+)在大脑功能中发挥的作用具有重要意义。我们开发了一种基于单链DNA诱导结构变化的微电极,用于高选择性地检测大脑中的K^(+)。电化学探针主要由三部分组成,其中适配体片段用于特异性识别K^(+),末端炔基基团用于高稳定组装探针于金表面,头部修饰的二茂铁基团作为电化学活性基团提供响应信号。结果表明通过合理地调控适配体的烷基链的长度,可以有效调节微电极的线性响应区间。其中优化后的电极LAC电极对K^(+)检测体现出了高的选择性,在10μmol·L^(-1)-10mmol·L^(-1)的线性范围展示了良好的线性关系。最终该新型微电极被成功应用于活体小鼠大脑中K^(+)的实时检测。

Potassium ion(K^(+))is widely involved in several physiopathological processes,and its abnormal changes are closely related to the occurrence of brain diseases of cerebral ischemia.In vivo acquirement of K^(+)variation is significant to understand the roles of K^(+)playing in brain functions.A microelectrode based on single-stranded DNA aptamers was developed for highly selective detection of K^(+)in brain,in which the aptamer probes were designed to contain an aptamer part for specific recognition of K^(+),an alkynyl group used for stable confinement of aptamer probe on the gold surface,and an electrochemical redox active ferrocene group to generate current response signal.The response range of the microelectrodes could be rationally tuned by varying the chain length of the aptamer probe.The optimized electrode,LAC,displayed high selectivity for in vivo detection of K^(+),and suitable linear range from 10 mmol·L-1e10 mmol·L-1,which could fulfill the requirement of K^(+)detection in brain.Eventually,the microelectrodes were successfully applied for the detection of K^(+)in the living mouse brains followed by hypoxic.