Novel amperometric assay for drug-DNA interaction based on an inhibitory effect on an electrocatalytic activity of DNA-Cu(II) complex

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• 作者：Tingting Gu^a ; ^{gutingting924@yahoo.com.cn} ; ^{gutingting@ustl.edu.cn} ; Yasushi Hasebe^b
• 关键词：Amperometric biosensor ; DNA-binding drug ; Inhibitor ; DNA&ndash ; Cu(II) complex ; Electrocatalytic activity
• 刊名：Biosensors and Bioelectronics
• 出版年：2012
• 期刊代码：12_09565663
• 类别：ch
• 出版时间：15 March, 2012
• 卷：33
• 期：1
• 页码：222-227
• 文件大小：658 K

摘要

A novel strategy of amperometric assay for drug-dsDNA interactions was developed based on an inhibitory effect of antimararial drug (quinacrine) on an electrocatalytic activity of DNA-Cu(II) complex. In this method, a DNA-Cu(II) complex immobilized DNA/polyallylamine(PAA) polyion complex membrane was used as a sensing element. The electrocatalytic activity of a DNA-Cu(II) complex for hydrogen peroxide reduction was reversibly inhibited by electron blocking effect of quinacrine-dsDNA interaction and this inhibitory effect was amplified by the hydrogen peroxide reduction. This phenomenon was utilized for development of a novel amperometric biosensor for DNA-binding drug. From the amperometric current-time curves, the response time of the sensor to 20 渭M quinacrine was obtained about 20 s, and the detection limit of the quinacrine was found to be 10 渭M estimated to a signal-to-noise ratio of 3.0. Based on the change of steady-state catalytic current, the kinetic analysis of drug-dsDNA interaction can be done in a similar manner of enzyme inhibition, and the binding constant of the quinacrine with DNA can be calculated. This measurement method would be useful for screening of wide variety of DNA-binding drugs and highly toxic pollutants.