Universal click-chemistry approach for the DNA functionalization of nanoparticles

TL;DR

This paper introduces a universal click-chemistry method for DNA functionalization of various nanoparticles, enabling stable colloids and high-yield self-assembly into optical antennas, expanding nanomaterials functionalization options.

Contribution

The authors develop a versatile click-chemistry approach for DNA functionalization applicable to diverse nanoparticle types, surpassing traditional thiol-based methods.

Findings

Achieved high DNA surface density on silica and silicon nanoparticles.

Enabled self-assembly into optical antennas with 78% yield.

Extended functionalization to oxides, polymers, core-shell, and metal nanostructures.

Abstract

Nanotechnology has revolutionized the fabrication of hybrid species with tailored functionalities. A milestone in this field is the DNA conjugation of nanoparticles, introduced almost 30 years ago, which typically exploits the affinity between thiol groups and metallic surfaces. Over the last decades, developments in colloidal research have enabled the synthesis of an assortment of non-metallic structures, such as high-index dielectric nanoparticles, with unique properties not previously accessible with traditional metallic nanoparticles. However, to stabilize, integrate and provide further functionality to non-metallic nanoparticles, reliable techniques for their functionalization with DNA will be crucial. Here, we combine well-established dibenzylcyclooctyne-azide click-chemistry with a simple freeze-thaw method to achieve the functionalization of silica and silicon nanoparticles, which form exceptionally stable colloids with a high DNA surface density of 0.2 molecules/nm2. Furthermore, we demonstrate that these functionalized colloids can be self-assembled into high-index dielectric optical antennas with a yield of up to 78% via the use of DNA origami. Finally, we extend this method to functionalize other important nanomaterials, including oxides, polymers, core-shell and metal nanostructures. Our results indicate that the method presented herein serves as a crucial complement to conventional thiol functionalization chemistry and thus greatly expands the toolbox of DNA-functionalized nanoparticles currently available.