Rhodium concave nanocubes and nanoplates as deep-UV resonant SERS platform

We report on the detection of molecules at the trace level using deep-UV surface-enhanced Raman spectroscopy (SERS) on shape-anisotropic rhodium (Rh) nanoparticles. Rh nanoparticles of three distinct morphologies, triangular nanoplates, rectangular nanoplates, and concave nanocubes, that exhibit strong plasmon resonances in the UV range were exploited for deep-UV SERS. With an enhancement factor greater than 10(5), Rh concave nanocubes demonstrate the highest SERS activity, which is well corroborated by electric field distribution maps calculated using finite-difference time-domain (FDTD) simulations. The deep-UV SERS substrate based on Rh concave nanocubes enables the detection of trace levels of explosive molecules such as p-nitrobenzoic acid and 2,4-dinitrotoluene with detection limits of 10(-10) M and 10(-7) M, respectively, and ammonium nitrate with a detection limit of 10(-12) M. Deep-UV SERS detection of explosive molecules on a low-cost and simple-to-fabricate Rh nanoparticles substrate holds tremendous potential for the SERS-based identification of hazardous materials.

Automated summary

We report the successful detection of trace-level molecules using deep-UV surface-enhanced Raman spectroscopy (SERS) on shape-anisotropic rhodium (Rh) nanoparticles. Rh concave nanocubes exhibited the highest SERS activity, with great detection sensitivity. The deep-UV SERS technology based on Rh nanoparticles holds tremendous potential for the identification of hazardous materials.