研制了用于研究DNA损伤的电化学发光传感器。在0.1 mol/L CdCl2和0.02 mol/L Na2S2O3(0.1mol/L HCl调节至pH 2~3,50℃)溶液中,采用循环伏安法(CV)在玻碳电极表面原位沉积硫化镉纳米晶,构建了硫化镉纳米晶修饰的电极界面(CdS QDs/GCE);以半胱氨酸为连接剂,利用羧氨键(CONH)将氨基修饰的短链DNA组装到CdS表面(DNA/CdS QDs/GCE)。以H2O2为共反应剂,利用电化学发光方法研究了全氟辛烷磺酸对DNA的损伤。结果表明,全氟辛烷磺酸温浴后的双链DNA修饰硫化镉的电化学发光信号强度介于单链和双链DNA之间,且随着全氟辛烷磺酸浓度的增加,电化学发光信号值变大,同时电化学阻抗曲线显示全氟辛烷磺酸致电极界面的电子传递性能降低。可以推测,PFOS可能导致DNA链的扭曲或断裂。
Electrochemiluminescence assay integrates the advantages of electrochemical potential controllability and high sensitivity of luminescence analysis.The electrochemiluminescence sensor was fabricated to further explore the DNA damage.CdS quantum dots was deposited on the surface of glassy carbon electrode in 0.1 mol/L CdCl2 and 0.02 mol/L Na2S2O3(0.1 mol/L HCl,pH 2-3,50 ℃) by cyclic voltametry,and then amino-modified single strand DNA was immobilized on CdS modified electrode by the CONH bond using cysteine as linker agent.The electrochemiluminescence was used to study the interaction between perfluorooctane sulfonates and DNA,and H2O2 was used as the common reactant.The results demonstrate that electrochemiluminescence signal value will be enhanced while perfluorooctane sulfonates concentration increases,and electrochemical impedance spectroscopy assay indicates that the DNA charge transfer attenuated due to perfluorooctane sulfonates incubation.These results reveal perfluorooctane sulfonates induce DNA chain distorted and changed.