Liquid Phase Interfacial Surface-Enhanced Raman Scattering Platform for Ratiometric Detection of MicroRNA 155

The self-assembly of gold nanoparticles (Au NPs) on a liquid phase interface is often employed as a surface-enhanced Raman scattering (SERS) platform with advantages of simple preparation, high reproducibility, and a defect-free character, but they are limited to only detect a target with Raman signals. To overcome this problem, microRNA 155 without a Raman signal can be detected by a liquid phase interfacial ratiometric SERS platform. Compared with the typical solid phase SERS platform, we propose a distinctive strategy not only owning the advantages of the liquid phase interfacial platform but also breaking the limitation of recent liquid-liquid interfacial SERS analysis. This platform presents a fabulous sensitivity with a limit of detection (LOD) of 1.10 aM for microRNA 155. By simply altering the duplex-specific nuclease (DSN) enzyme amplification, our strategy can realize detection of a variety of microRNAs, paving the way to practical applications of a liquid phase SERS platform.