A novel electrochemical DNA detection method based on bio-barcode/gold label silver stain dual amplification

A novel electrochemical gene detection method based on bio-barcode/gold label silver stain (GLSS) dual amplification is presented. The silica nanoparticle/gold nanoparticles (SiO2/AuNPs) barcode probes were constructed by combining SiO2 nanoparticle-labeled DNA with AuNPs, which hybridizes with target DNAs and the electrode surface-modified DNA probes. The silver ions were reduced on the surface of AuNPs to form a silver shell by the catalysis of AuNPs, and then the electrochemical detection of deposited silver was performed by linear sweep voltammetry (LSV). In this paper, the effects of electrode blocking agent, blocking time and silver deposition time on electrochemical detection were also investigated. The proposed electrochemical DNA biosensor bring forth a low detection limit of 0.23 fM and a widely linear range of 1 fM to 10 pM. This method can clearly distinguish the complementary and mismatched DNA, with good repeatability and stability.