Investigation of sensitive SERS detection via a perovskite-coated Ag nanofilm

Surface-enhanced Raman scattering is a powerful spectroscopy technique due to its ultra-sensitive characterization. However, it is usually detected based on direct contact between the noble metal substrates and the probe molecule, which limits the practical applications. Here, we propose a detection method to construct an all-inorganic perovskite CsPbIBr₂ on the surface of a silver nanofilm for surface-enhanced Raman scattering applications. The perovskite film is coated on the surface of a silver nanofilm as the protection layer and a signal amplifier to achieve high sensitivity detection without direct contact between the probe molecule and the noble metal layer. The interaction and enhancement mechanism between the components were discussed, which provided a lower detection limit for the analysis of p-mercaptobenzoic acid and rhodamine. This study provides an easy-to-prepare and high-sensitivity perovskite-based substrate for SERS-related applications, promotes the understanding of charge transfer in nanocomposite substrates, expands the class of SERS substrates, and is conducive to providing a wide range of applications and platforms in various fields.