基于金纳米粒子/聚阿魏酸/多壁碳纳米管修饰电极的DNA计时库仑法生物传感器的制备

摘要

A sensitive chronocoulometric DNA biosensor was fabricated based on gold nanoparticles (AuNPs)/poly ( ferulic acid) ( PFA)/multiwalled carbon nanotubes ( MWCNTs) modified glassy carbon electrode (GCE). Ferulic acid (FA) was firstly electropolymerizated on the surface of the electrode modified with MWCNTs by cyclic voltammetry (CV), and AuNPs were subsequently introduced to the surface of the PFA film by electrochemical deposition. Finally, DNA probes (HS-DNA) were immobilized on the surface of the AuNPs/PFA/MWCNTs/GCE via Au-S bond.Electrochemical impedance spectra (EIS) and scan electron microscopy (SEM) were used to investi gate the fabrication process of this biosensor. The DNA hybridization events were monitored by chronocoulometry (CC) technique and hexaammineruthenium(Ⅲ) chloride (RuHex) was used as the electrochemical indicator. Under the optimal conditions, the signal of RuHex was linear with the logarithm of the concentration of the target DNA from 1. 0×10-14 mol/L to 1.0×10-9 mol/L with a detection limit of 3. 5 × 10-13 mol/L. Moreover, the DNA biosensor exhibited excellent reproducibility and stability.%构建了基于金纳米粒子/聚阿魏酸/多壁碳纳米管(AuNPs/PFA/MWCNTs)修饰电极的DNA计时库仑法生物传感器.利用循环伏安技术在多壁碳管修饰的玻碳电极表面上聚合一层阿魏酸,在恒电位条件下,在阿魏酸表面沉积金纳米粒子,巯基DNA作为探针通过金硫键固定在金纳米粒子表面.电化学交流阻抗技术(EIS)与扫描电镜(SEM)用于表征DNA传感器的构筑过程.以六氨基合钌(RuHex)作为杂交指示剂,采用计时库仑法进行检测.在最佳实验条件下,检测信号与待测DNA浓度(1.0×10(-14)～1.0×10(-9)mol/L)的对数呈线性关系;检出限为3.5×10(-15)mol/L(S/N=3).此传感器具有良好的稳定性和重现性.