Amphiphilic Plasmonic Microgels for Interfacial Stabilization and SERS-Based Molecular Detection of Biological Fluids

Abstract

Surface-enhanced Raman scattering (SERS) is one of the useful analytical methods for sensing small molecules. However, preparation of substrate with metallic nanostructure is time-consuming, and detecting target molecules in a complex mixture is challenging. In this study, we design a facile method to create amphiphilic plasmonic microgels via micromolding method. Microgel is composed of two compartments by sequential molding in cylindrical hole arrays of PDMS molds. One side of the microgel is plasmonic compartment featured by gold nanoparticles for SERS analysis and hydrogel network excluding adhesive molecules. The concentration of photoinitiator and gold precursor is optimized for SERS sensitivity. Polymerized PFPE diacrylate, which has hydrophobicity makes up the other compartment. The resulting microgels can stabilize the interface between oil and water, indicating the potential of SERS analysis of target molecules present in a small amount of water contaminated by oil.