Compact dual-fiber surface-enhanced Raman scattering sensor with monolayer gold nanoparticles self-assembled on optical fiber

Employing a self-assembly method and dual-fiber structure, a compact, low-cost, highly sensitive, fast surface-enhanced Raman scattering (SERS) optical fiber sensor was realized. Through detecting a SERS signal of 10 ppm rhodamine B analyte, sensor parameters such as coupling angle, fiber types, and corresponding glass substrate structure were optimized. The ratio of the SERS signal intensity to excitation light residual peak intensity was used as a significant parameter during the optimization process. Sensor characteristics such as the SERS signal dependence on excitation power, stability related to excitation time, and reusability were studied. Its compatibility in size with microfluidic structure would make it a prospective candidate for integrating into a microfluidic chip.