Asymmetric functionalization of gold nanoparticles with oligonucleotides

Abstract

Gold nanoparticles (AuNPs) were anisotropically functionalized with two different oligonucleotide sequences using magnetic microparticles as geometric restriction templates for site-selective enzymatic extension of particle-bound oligonucleotides. The divalent linking capability of the resulting AuNPs allowed for the design and programmable assembly of discrete nanoparticle heterostructures.

Figure 1

(a) DNA melting curves of 13 nm AuNPs that are hybridized with MMPs through an extension DNA. The ligation step significantly increased the melting temperature, from 54 °C, before (red), to 74.5 °C, after (blue). Without the extension DNA, the ligation step showed minimal effect (black curve). (b) SEM image showing 30 nm AuNPs on the surface of a MMP.

Figure 2

Directional assembly of asymmetrically functionalized AuNPs into (A, B) cat paw, (C, D) satellite, and (E, F) dendrimer-like structures. Inset: scale bar = 20 nm.

Scheme 1^a

^a Note that we are not intending to imply that particle 6 has a single extended linker, but rather a small collection of extended oligonucleotides localized in one region.