利用带正电荷的聚二甲基二烯丙基氯化铵(PDDA)和带负电荷的小牛胸腺双链DNA(CT-dsDNA)之间的静电吸引作用,将其层层组装到玻碳电极表面,制成电化学DNA传感器,并利用电化学和原子力显微镜(AFM)方法与对DNA的组装进行了表征.以Ru(bpy)32+作为电化学催化剂,检测DNA的损伤,考察了电极在Fenton试剂中的温育时间以及Fenton试剂的浓度对DNA损伤程度的影响.实验表明,Fe2+与H2O2共存时,温育15 min即可较大程度地对DNA造成损伤,且可以检测到的Fenton试剂浓度为5.0× 10-5 mol/L FeSO4/2.0× 10-4 mol/L H2O2.本方法具有灵敏度高、重现性好等优点.%Layer-by-layer films of poly dimethyl diallyl ammonium chloride and DNA were assembled on the surface of a glassy carbon electrode to prepare DNA electrochemical sensor. The assembling of DNA was characterized by employing electrochemical methods and atomic force microscope. We used Ru(bpy)|+ as electrochemical catalyst to detect the oxidative damage of DNA in the membrane. The effects of incubation time and concentration of Fenton reagent on the damage of DNA were studied. The result showed that DNA could be damaged greatly when it was incubated in Fenton reagent for 15 min. The detectable concentration of Fenton reagent was 5. 0×10-5 mol/L FeSO4/2. 0× 10-4 mol/L H2O2. The electrochemical method using Ru(bpy)23+ as catalyst possesses high-sensitivity for detecting the damage of DNA.
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