Preparation And Application Of Self-Assembled DNA Electrochemical Biosensor

In this paper, a gene electrochemical biosensor was prepared by self-assembled method, using the methylene blue (MB) and toluidine blue (TB) as the indicator respectively. The interaction model of indicator with ssDNA or dsDNA was investigated by UV-Vis adsorption spectrophotometry and cyclic voltammetry. The interaction of methyl violet (MV) with fsDNA was also investigated by linear sweep voltammetric technique.The paper is made up of five parts. Firstly, a summary referring to the genetically modified organism, the significance of the electrochemical biosensor, and the interaction of DNA with small molecules were reviewed. Secondly, the electrochemical behaviors of self-assembled modified gold electrode with mercaptoacetic acid were preliminarily studied by cyclic voltammetric technique. The results showed that a self-assembled monolayer was formed on the surface of gold electrode. Thirdly, a NOS gene electrochemical biosensor was prepared by covalently immobilizing of single-stranded NOS ssDNA sequence on the mercaptoacetic acid monolayer self-assembled gold electrode with the help of N-(3-dimethyIaminopropyl) -N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The electroactive indicator, methylene blue (MB), is used to monitor the recognition of the DNA. Forthly, the interaction model of toluidine blue (TB) with ssDNA or dsDNA was...