Fabrication of hydrogels with nanoparticles as surface-enhanced Raman scattered (SERS) substrates and their application in Raman imaging

Abstract

Abstract A polyvinyl alcohol–silver nanoparticle (PVA–Ag NP) hydrogel was fabricated using a simple and facile method; it was used as a substrate for surface-enhanced Raman scattering (SERS). The Ag+ ions dispersed uniformly in the PVA network were reduced by NaBH4; this process was termed dipping method. Compared with conventional SERS substrates (e.g., colloidal suspensions), the prepared PVA–Ag NP hydrogel has prominent Raman enhancement effects for crystal violet (CV), and the detection limit was 10−12 M. It could also help detect rhodamine B, methylene blue, and 4-mercaptobenzoic acid. In addition to SERS, the reliable 3D porous structure was utilized in the Raman imaging of CV at 1621 cm−1 in a nude mouse.