利用层层自组装,将多壁碳纳米管(MWNTs)和金纳米粒子(GNPs)标记的DNA固定在金电极表面,结合两种不同类型的杂交指示剂构成电化学DNA传感器,用循环伏安法和差分脉冲伏安法研究了传感器的电化学行为.结果表明:这两种指示剂都能通过差分脉冲伏安法实现单碱基错配DNA的特异性检测,阳离子型杂交指示剂亚甲基蓝(MB)的最佳吸附时间为50 min,检测限为2.69× 10-9 mol/L;阴离子型杂交指示剂单磺酸基蒽醌(AQMS)的最佳吸附时间为8h,检测限为3.81×10-11 mol/L.%A novel DNA biosensor is prepared based on layer-by-layer self-assembled multi-walled carbon nanotubes (MWNTs) and Aurum nanoparticles (CNPs) which fixed on the gold electrode surface, and combined with different types of electrochemical DNA hybridization indicator. The cyclic voltammetric and differential pulse voltammetry are used to investigate the electrochemical behavior of these biosensors. The results show that the two DNA/GNPs/SH-MWCNTs/Au biosensor are enabled to specifically detect the single-base mismatch DNA sequence with differential pulse voltammetry method. The optimum adsorption time of the cationic methylene blue indicator hybrid (MB)is 50 min, the detection limit is 2.69x10^ mol/L. The optimum adsorption time of the anion anthraquinone-2-sulfonic acid sodium salt indicator hybrid ( AQMS) is 8 h, and the detection limit is 3.81x10-" mol/L.
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