Ion-specific aggregation of gold-DNA nanoparticles using the dG quartet hairpin 5 `-d(G(4)T(4)G(4))

Abstract

Ion-selective self-assembly of An nanoparticles is described. The Oxytricha telomere DNA hairpin 5'-d(G(4)T(4)G(4)) immobilized on 13-nm Au nanoparticles forms a supramolecular assembly via dG-quartets, as determined by the color change and by scanning electron microscopy (SEM). The aggregation is ion-dependent and selective for Na+ ions. K+ is less efficient, while Li+ and Cs+ do not drive the aggregation. This work is the first effort to explore the use of secondary structures of DNA (quadruplexes) for producing self-assemblies of Au nanoparticles. It can be utilized to generate novel devices and materials, potentially useful for sensing and other applications in medicinal or engineering science.