Boron Nitride Nanosheets as Improved and Reusable Substrates for Gold Nanoparticles Enabled Surface Enhanced Raman Spectroscopy

TL;DR

This paper demonstrates that atomically thin boron nitride nanosheets serve as effective, reusable substrates for gold nanoparticle-enabled surface-enhanced Raman spectroscopy, offering improved sensitivity and minimal interference.

Contribution

It introduces a controllable synthesis method for Au nanoparticles on BN nanosheets and shows their superior SERS performance and reusability compared to traditional substrates.

Findings

BN nanosheets enhance Raman signals more than silicon or bulk BN.

Au/BN substrates are reusable after heating to remove analytes.

Au particle size depends on BN thickness and sputtering conditions.

Abstract

Atomically thin boron nitride (BN) nanosheets have been found an excellent substrate for noble metal particles enabled surface enhanced Raman spectroscopy (SERS), thanks to their good adsorption of aromatic molecules, high thermal stability and weak Raman scattering. Faceted gold (Au) nanoparticles have been synthesized on BN nanosheets by a simple but controllable and reproducible sputtering and annealing method. The size and density of the Au particles can be controlled by sputtering time, current and annealing temperature etc. Under the same sputtering and annealing conditions, the Au particles on BN of different thicknesses show various sizes because the surface diffusion coefficients of Au depends on the thickness of BN. Intriguingly, decorated with similar morphology and distribution of Au particles, BN nanosheets exhibit better Raman enhancements than silicon substrate as well as bulk BN crystals. Additionally, BN nanosheets show no noticeable SERS signal and hence cause no interference to the Raman signal of analyte. The Au/BN substrates can be reused by heating in air to remove adsorbed analyte without loss of SERS enhancement.