DNA array biosensor based on electrochemical hybridization and detection

A novel array biosensor was developed to assay DNA fragments in which the electrochemical method was used to accomplish rapid hybridization as well as detection. The DNA capture probes were immobilized on a photolithographically gold array electrode by self-assembly and chemical conjugation technique. The target sequence was detected by coupling avidin-alkaline phosphatease to the biotinylated DNA fragments and measuring the current signal obtained from the hydrolysis of alpha-naphthyl phosphate. Compared with the regular hybridization, the novel electrochemical approach could significantly enhance hybridization speed. The present method was further employed to quantitatively detect the PCR products of hepatitis B virus plasmid. In addition, the array biosensor also proved able to screen multicomponent samples.