Wide-Band Spectral Control Of Au Nanoparticle Plasmon Resonances On A Thermally And Chemically Robust Sensing Platform

Abstract

Gold nanoparticles on Al2O3-coated gold films are presented as a chemically and thermally robust platform for molecular sensing. Single particle spectroscopy as a function of Al2O3 coating thickness shows reproducible gold nanoparticle scattering spectra in the range from 690 to 610 nm as the Al2O3 thickness increases from 0 to 3.4 nm. Numerical simulation of these structures indicates that surface-enhanced Raman spectroscopy enhancement factors in excess of 10 6 can be achieved. The stability of the Al2O 3-coated structures under high-power laser irradiation was tested, revealing stable scattering spectra upon irradiation with 100 W/mm2 at the particle resonance wavelength. The presented structure solves challenges with thermal stability, wavelength tuning range, and Raman background signal associated with previously attempted approaches. © 2013 American Chemical Society