PDDA/MWNT自组装膜修饰碳纤维微电极选择性测定多巴胺的研究

Study on PDDA/MWNT self-assembled monolayer modified carbon fiber microelectrodes for selective detection of dopamine

结合了碳纳米管和微电极两者的优越性,通过静电自组装方法有序地将混酸切割多壁碳纳米管修饰到碳纤维微电极上,并表征了自组装膜PDDA/MWNT修饰到碳纤维微电极上的均匀程度和稳定性,进一步采用循环伏安法研究了多巴胺和抗坏血酸在该修饰电极上的电化学行为。结果表明,该修饰微电极成功实现在抗坏血酸共存下选择性测定多巴胺,峰电流与多巴胺浓度在4μM/L到52μM/L之间呈现良好的线性关系,最低检测限是0.1μmol/L,该工作为多巴胺的活体、实时的电化学选择性测定奠定了基础。

A new electrochemical method to integrate both virtues of carbon nanotubes （CNTs） and microelectrodes was demonstrated. By use of self-assembly method based on electrostatic interaction, multi-walled carbon nanotubes （MWNTs） treated and shortened in 1：3 concentrated nitric-sulfuric acid was attempted to assembly onto carbon fiber mi- croelectrodes. Furthermore,the stability and homogeneity of the assembled PDDA/MWNT monolayer were characterized and the electrocatalysis effect of PDDA/MWNT for the oxidation of dopamine and ascorbate was demonstrated. The results indicated that the as-assemled microelectrode can selectively detect dopamine with the coexistence of ascorbate,which estab-lished the foundation for in vivo, real-time, selective determination of dopamine.