电流型DNA传感器检测Pb^(2+)对DNA的损伤

Detection of Pb^(2+)-induced DNA Damage with an Amperometric DNA Sensor

在玻碳电极(GCE)表面依次电聚合硫堇(PTh)膜、电沉积普鲁士蓝包金纳米粒子(PB@Au)、电沉积纳米金粒子(Au NPs),利用Au NPs大的比表面积和良好的生物相容性,进而固定双链DNA(dsDNA),制备一种电流型DNA传感器(GCE/PTh/PB@Au/Au NPs/dsDNA).利用电化学交流阻抗技术(EIS)和循环伏安法(CV)对dsDNA修饰电极进行表征,以亚甲基蓝(MB)为杂交指示剂,利用微分脉冲伏安法(DPV)对Pb2+对DNA的损伤进行了检测.结果表明,利用所制备的GCE/PTh/PB@Au/Au NPs/dsDNA可以高灵敏地测定铅金属离子对dsDNA损伤的程度,在25~45℃温度范围内,Pb2+对DNA的损伤速度随着温度升高而加快,Pb2+浓度越大对DNA的损伤越严重,即使微量的Pb2+对DNA也有明显的损伤.所制备的传感器灵敏准确,可用于其他重金属离子的检测以及基因损伤的研究.

An amperometric DNA sensor（ GCE /PTh /PB@ Au /Au NPs /dsDNA） has been presented in this paper. First,thionine was electro-polymerized（ PTh） onto a glassy carbon electrode（ GCE）,then Prussian blue shell / Au core（ PB @ Au） and Au nanoparticles（ AuNPs） were successively electro-deposited on the GCE modified with PTh. Finally,Double stranded deoxyribonucleic acid（ dsDNA） was immobilized on the electrode due to the large specific surface area and good biocompatibility of AuNPs. The modifying process mentioned above was characterized by electrochemical impedance spectroscopy（ EIS） and cyclic voltammetry（ CV）. The Pb2 ＋-induced of DNA damage was detected with the sensor by differential pulse voltammetry（ DPV） using methylene blue（ MB） as hybridization indicator. The results showed that the novel DNA sensor could sensitively detect the damage degree of DNA. The damage increased with the increasing of temperature from 25 to 45 ℃ and with the increasing of Pb^2 ＋concentration. In fact,though Pb^2 ＋concentration was trace,the damage was obviously detected. In a word,the novel DNA sensor is very sensitive,accurate and can be used to detect other heavy metal ions as well as genetic damage.