DNA-Guided One-Dimensional Plasmonic Nanostructures for the SERS Bioassay

Plasmonic nanostructures have a desirable surface-enhanced Raman scattering (SERS) response related to particle spacing. However, precisely controlling the distance of plasmonic nanostructures is still a challenge. DNA has the merit of specific recognition, and flexible modification of functional groups, which can be used to flexibly adjust the gaps between plasmonic nanostructures for improving the stability of SERS. In this paper, DNA-guided gold nanoparticles formed one-dimensional ordered structures and they were self-assembled at the water-oil interface by a bottom-up approach. Notably, an output switching strategy successfully transfers a small amount of target into a large amount of reporter DNA; thereby, Raman probes are captured on the sensing interface and achieve the SERS assay of microRNA 155 (miRNA-155). This study is an exciting strategy for obtaining ordered plasmonic structures and providing surveillance, which is important for the clinical diagnosis of early-stage cancer.