Structured Gold Films Deposited on Uncured Polydimethylsiloxane for SERS Applications

Abstract

We present a template-based approach for preparing highly structured metallic films as effective surface-enhanced Raman scattering (SERS) substrates on the surface of uncured polydimethylsiloxane (PDMS). In contrast to the commonly used liquid substrates, such as silicone oil and ionic liquid, uncured PDMS is distinguished by its controlled viscosity, rendering it suitable as an adjustable and stable liquid substrate. On the other hand, by curing at appropriate times, it can be easily transferred into cured PDMS substrate with high flexibility. With the assistance of polystyrene microsphere templates, highly structured gold (Au) films can be deposited on the surface in a controlled manner. Through the control of film morphology, these films were demonstrated to have significantly enhanced Raman signal of probe molecules, indicating their effectiveness as a sensitive SERS substrate. This work provides an effective solution to address the instability of metallic films on the surface of liquid substrates and achieves superior SERS performance, offering potential applications of flexible SERS sensors for in situ molecular tracking and detection.