硫堇与DNA的相互作用及用于DNA电化学传感器

在0.20 mol.L-1pH 5.0 NaAc-HAc缓冲溶液中,运用电化学方法和荧光光谱分析法研究了硫堇与鲑鱼精DNA的相互作用。硫堇与DNA作用后,氧化还原峰电流减小,峰电位正移,溴化乙锭(EB)-DNA体系在加入硫堇后出现荧光猝灭的现象。结果表明,硫堇与DNA的结合方式主要为嵌插作用。以硫堇为电化学杂交指示剂,制得了一种DNA电化学生物传感器,该传感器具有良好的选择性,靶DNA在11.3~121 nmol.L-1范围内具有良好的线性关系,线性相关系数0.997 1,检测限为5.26 nmol.L-1(3σ,n=7)。

Interaction Between Thionin and DNA and the Application in DNA Electrochemical Biosensors

The interaction between thionin and salmon sperm DNA in 0.20 mol·L-1 at pH 5.0 NaAc-HAc buffer solution was studied by electrochemistry and fluorescence spectroscopy.The peak current of thionin decreased with positive shift of the formal potential in the presence of DNA compared with that in the absence of DNA.Quenching fluorescence phenomenon appeared for ethidium bromide(EB)-DNA system when thionin was added to.All the experimental results indicate that thionon can bind to DNA mainly by intercalatively binding mode.A good selectivity was obtained using thionin as an indicator of DNA electrochemical biosensors.The target ssDNA could be quantified within the range from 11.3 to 121 nmol·L-1with good linearity(γ=0.997 1)and detection limit of 5.26 nmol·L-1(3σ,n=7)was achieved by the constructed electrochemical DNA biosensor.