利用自组装单分子膜技术将巯己基修饰的单链DNA 固定在金电极表面,以电活性的Hoechst33258 为指示剂,考察了单链DNA 修饰电极(ssDNA/ Au 电极) 、双链DNA 修饰电极(dsDNA/ Au 电极) 的指示剂氧化峰电流, 并利用其差值(Δip) 与互补DNA浓度成线性关系对待测DNA浓度进行定量。因此,DNA 电化学传感器可用于特定DNA 序列的识别和测定。关键词: 脱氧核糖核酸; 电化学传感器; 修饰电极Abstract : Thiol2derivatized ss2DNA is fixed on the surface of Au electrode using self2assemble film method. Hoechst 33258 is used as electro2active indicator. The peak current of indicator on ss2DNA modified electrode and ds2DNA modi2 fied electrode is observed respectively ,the difference of which has linearity with concentration of complementary DNA. So it is used for quantification of specific DNA. DNA electrochemical sensor can be used in the recognition and detection of specific DNA.Key words : DNA; electrochemical sensor ; modified electrode