电化学DNA传感器中DNA的固定与杂交条件探讨

利用自组装单分子膜法,将人工合成的乙肝病毒单链DNA片断作为特异性探针固定在金电极表面,结合电活性指示剂Hoechst33258构成DNA电化学传感器。在乙肝特异性DNA探针的自组装固定过程中,探讨了自组装单分子膜的成膜条件,总结出在探针浓度为100mg/L,自组装固定时间为12h对DNA探针的固定较为有利。考察了单链DNA修饰电极的伏安特性和单链DNA修饰电极的电子传递性能。在对标准互补DNA溶液的杂交检测过程中,探讨了杂交时间、杂交温度、指示剂的作用时间等对DNA传感器检测的影响。当杂交时间为90min,杂交温度为25℃,杂交溶液中NaCl浓度为0.3mol/L时,指示剂的伏安信号较好。

Study of DNA immobilization and hybridization of DNA electrochemical sensor

The electrochemical sensor is prepared by self-assembling the designed hepatitis B virus DNA specific probe on the surface of the gold electrode together with Hoechst 33258 as the electro-active indicator.The condition for self-assemble single-molecular film is chosen during experiments as the following: probe concentration is 100mg/L,self-assemble time is 12h.The voltammetry characteristic and the electron-transfer capability of single-strand DNA modified gold eletrode are observed.The effect of hybridization time,hybridization temperature and intercalation time on the detection result is discussed.The optimized response of indicator can be got while hybridization time and temperature is 90min and 25℃ and NaCl in hybridization solution is 0.3mol/L.