Etching-free fabrication method for silver nanowires-based SERS sensors for enhanced molecule detection

Surface-enhanced Raman spectroscopy (SERS) has garnered increasing attention for its ability to detect molecules even at low concentrations; however, the fabrication methods for SERS sensors require further study aimed at simple and rapid on-body and environmental monitoring. In this context, we propose an etching-free method for fabricating silver nanowires (AgNWs)-SERS sensors based on AgNWs. A lift-off process was conducted to create a pattern without etching, and lamination of the dry film resist overcame the limitations associated with liquid photoresists. Consequently, the resulting AgNW-patterned substrate was used to evaluate the pH of the test solution in the range of 1.1 and 12.0 and exhibited a Raman signal enhancement of 2 × 10⁶. This fast and cost-effective fabrication method, combined with the intrinsic flexibility of the substrate and rapid and reproducible response to pH variations, provides a foundation for applying AgNW-patterned substrates for microenvironmental analysis or developing wearable optical devices.