DNA电化学传感器结合了电分析化学和DNA杂交的特点,具有灵敏度高、特异性好及操作简单等优点,应用前景广阔.常用的ssDNA固定方法有吸附法、共价键合法、自组装法、生物素-亲和素法及组合法等.其中自组装法是根据分子的自组装作用,在电极表面形成高度有序的ssDNA单分子层建立的.
A NOS gene electrochemical biosensor was prepared by covalently immobilizing of NOS ssDNA sequence on the mercaptoacetic acid monolayer self-assembled gold electrode with the help of N-(3-dimethyl-aminopropyl) -N'-ethylcarbodiimide hydrochloride ( EDC ) and N-hydroxysuccinimide (NHS). By using methylene blue as the electrochemical indicator, the increase of cathodic peak current was in linear with the concentration of complementary ssDNA in the concentration range of 5.0 × 10^-8 —1.0 × 10^-4 mol/L with the linear regression equation as△Ipc = 1. 10lgc + 8.25 ( n = 8, γ = 0. 998 5 ) and the detection limit as 3.60 × 10^-8 mol/L(3σ).