Probing the conjugation of gold NPs using single-stranded DNA comprising two polyadenine adhesive tails

Abstract

ABSTRACT The spatial arrangement of nanoobjects by using DNA is a promising nano-design technology. Polyadenine adhesive tails are increasingly used to anchor functional oligonucleotides on the surface of gold nanoparticles at low pH. Further hybridization of such functional oligonucleotides allows nanoparticles to be organized within the desired design. In this work, we studied the effect of temperature, ionic strength, and strand design on the adsorption rate of polyadenines on the surface of gold nanoparticles at different pH. We found that there are temperature and ionic strength ranges in which the adsorption rate increases and vice versa. There are also significant differences in the effects of monovalent sodium and divalent magnesium ions. We have shown that dual-tail DNA strand design allows for increased surface density, which is significantly higher than that obtained with the standard one-tail strand design.