Surface-enhanced Raman spectroscopy with gold nanoparticle dimers created by sacrificial DNA origami technique

Abstract

In a previously proposed method for molecular detection based on surface-enhanced Raman spectroscopy (SERS), gold nanoparticle (AuNP) dimers are formed on a substrate using DNA origami with a nanometre-scale gap between them. In this sacrificial DNA origami technique, a conjugate of two AuNPs and a DNA origami is deposited on a silicon chip, and then the DNA origami is selectively removed using vacuum ultraviolet light and ultrapure water rinsing to form surface-clean AuNP dimers. The performance of SERS-based molecular detection of AuNP dimers created using the proposed technique with a 30 nm AuNP diameter has now been evaluated. The Raman signals from the target molecules (4,4'-bipyridine) were greatly enhanced and thus successfully detected.