Nanoparticle-Decorated Nanocanals for Surface-Enhanced Raman Scattering

Abstract

Nanocanal arrays composed of uniformly aligned vertical cylindrical pores with inner walls decorated with gold nanoparticles as robust and cost-efficient surface enhanced Raman scattering (SERS) substrates with significant SERS enhancement were introduced. A representative cross-sectional microscopic image of decorated nanocanals within porous alumina membranes show that most of the gold nanoparticles are immobilized in an isolated state with occasional aggregated clusters. The scanning electron microscopic (SEM) analysis images show that very few nanoparticle aggregates, which could not contain hot spots, are present in substrates. The SERS enhancement of 2D substrate with relatively low concentration and very few aggregates of gold nanoparticles is found to be 10, owing to a rare presence of hot spots.