▎ 摘　　要

NOVELTY - Method for preparing electrochemical DNA biosensor involves using carbon-paste electrode which is modified by carbon ionic liquid electrode (CILE), fixing three-dimensional (3D) graphene and dendritic nanogold on electrode surface, using gold-sulfur (Au-S) and mercaptoacetic acid (MAA) between the covalent bond of nanoparticle, immobilizing single-stranded DNA (ssDNA) on the surface of electrode to form ssDNA modified interface, completing hybridization between probe ssDNA and target ssDNA using drop coating method, and detecting target ssDNA. USE - The method is useful for preparing electrochemical DNA biosensor (claimed). ADVANTAGE - The prepared electrochemical DNA biosensor has good sensitivity and low detection limit. DETAILED DESCRIPTION - Method for preparing electrochemical DNA biosensor involves using carbon-paste electrode which is modified by carbon ionic liquid electrode (CILE) as base electrode, sequentially fixing three-dimensional (3D) graphene and dendritic nanogold on the electrode surface, using gold-sulfur (Au-S) and mercaptoacetic acid (MAA) between the covalent bond of nanoparticle to form a stable self-assembled monolayer modified electrode MAA, immobilizing single-stranded DNA (ssDNA) on the surface of the electrode by condensation reaction to form ssDNA modified interface, completing hybridization between probe ssDNA and target ssDNA using drop coating method, and detecting target ssDNA.