DNA-functionalized gold nanoparticle assemblies for Surface Enhanced Raman Scattering

TL;DR

This paper demonstrates a DNA-mediated assembly of gold nanoparticles that creates stable, reproducible SERS sensors with controlled nanoscale organization, advancing nanostructure design for sensing applications.

Contribution

It introduces a programmable DNA-based method for assembling gold nanoparticles into stable structures with predictable SERS responses, enhancing nanostructure control.

Findings

DNA-assembled gold nanoparticle aggregates show enhanced SERS signals.

Controlled interparticle distances lead to reproducible SERS responses.

The system functions as a stable, biocompatible, and recyclable SERS sensor.

Abstract

The programmable assembly of DNA strands is a promising tool for building tailored bottom-up nanostructures. Here, we present a plasmonic nanosystem obtained by the base-pairing mediated aggregation of gold nanoparticles (NPs) which are separately functionalized with two different single-stranded DNA chains. Their controlled assembly is mediated by a complementary DNA "bridge" sequence. We monitor the formation of DNA assembled NP aggregates in solution, and we study their Surface Enhanced Raman Scattering (SERS) response by comparison with the single NP constituents. We interpret the revealed SERS signatures in terms of the molecular and NP organization at the nanoscale, demonstrating that the action of the DNA bridge molecule yields regular NP aggregates with controlled interparticle distance and reproducible SERS response. This demonstrates the potential of the present system as a stable, biocompatible, and recyclable SERS sensor.