Plasma induced synthesis of water-soluble DNA conjugated gold nanoparticles

摘要

A gas-liquid interfacial discharge plasma (GLIDP) is used to synthesize gold nanoparticles (AuNPs) from an aqueous solution of chloroauric acid trihydrate with or without 30-mer single-stranded DNA containing guanine. When the GLIDP irradiates on the aqueous solution, gold (III) is reduced to gold (0) by reducing agents generated in the gas-liquid interface by the plasma irradiation. After stopping the plasma irradiation, we find that the AuNPs continually nucleate and grow, which is attributed to the presence of H_2O_2 generated in the solution by the plasma irradiation. The AuNPs are soluble in solution for the case with DNA, but sink partly toward the bottom for the case without DNA. We suggest that DNA is conjugated on the surface of the synthesized AuNPs, which not only prevents the AuNPs from further growth, but also makes the AuNPs soluble in water.