Cotton Swab-Based Surface-Enhanced Raman Spectroscopy Substrate for Ultrasensitive Detection with Year-Long Stability and Multiple Recyclability

In recent years, the development of surface-enhanced Raman spectroscopy (SERS) substrates has seen significant advancement. In this research, we successfully fabricated cotton swab-based SERS substrates using a facile solution-based method. Our SERS substrates showed not only ultrasensitive detection capability but also impressive long-term stability and multiple recyclability rounds. In particular, we reported a detection limit of 10−12 M RhB and a detectable concentration of thiophanate methyl as low as 10−10 M using our cotton swab-based SERS substrates. The stability of our substrates reached a 12-month mark, and they were recycled as many as five times simply by cleaning them with ozone.