Dual-functional optical fiber SERS probe with high sensitivity and self-cleaning

This paper proposes a surface-enhanced Raman scattering (SERS) probe based on silver nanocubes (Ag NCs) on a tapered optical fiber, offering both high sensitivity and self-cleaning functionality. The Ag NCs were synthesized using a polyol method and subsequently deposited uniformly onto the fiber surface via laser-induced deposition to construct the SERS probe. Experimental results show that the probe can detect Rhodamine 6 G (R6 G) as low as 10^-11 mol/L, with an analytical enhancement factor (AEF) of 6.77 × 10⁸. Laser irradiation promotes the desorption of surface molecules of the optical fiber SERS probe, enabling efficient cleaning. The Raman signals remain highly stable over four cleaning cycles, confirming the probe's superior performance in repeated use. The probe is also capable of recognizing multiple molecules, including R6 G, malachite green (MG), and crystal violet (CV). Furthermore, Raman detection of uric acid at 50 μmol/L and uremic acid at 1 mmol/L concentrations was also achieved. This study provides new insights for high-sensitivity, low-cost, and reusable SERS sensors, with significant potential for applications in biomedical and environmental monitoring.