Abstract:

The grapheneAuNPs hybrid was achieved with sodium citrate as a reductant and stabilizer and was functionalized by carboxyl group. DNA was successfully bound to the surface of the hybrid through a condensation reaction between the terminal amino group on the lysine residues of DNA and carboxyl group on  AuNPs. A novel model of the DNA biosensor based on the grapheneAuNPs hybrid electrode was fabricated. The sodium 9, 10dihydro 9, 10dioxoanthracene2sulphonate (AQMS) was used as the hybridization indicator for the target DNA detection. The results show that the DNA biosensors fabricated with the grapheneAuNPs  selectively distinguishs the singlebase mismatch of target DNA sequence and shows a higher specific selectivity.

Key words: DNA biosensor, DNA immobilization, graphenegold nanoparticles hybrid, sodium citrate