Real-time detection of chemicals using tapered optical fiber

We manufactured a tapered optical fiber using a dynamic etching process and used it to detect chemicals in real-time by obtaining Raman spectra. This report focuses on two methodologies of obtaining Raman spectra: (a) bare tapered fiber was dipped in the mixture of GNRs and analyte, and (b) surface-enhanced Raman scattering (SERS) substrate was developed by depositing gold nanorods (GNRs) on the tapered fiber surface via optical tweezing, and tweezed fiber was dipped into the analyte solution. In both cases, the minimum concentration detected for rhodamine 6G (R6G) and crystal violet (CV) was 10 −7 M and 10 −8 M, respectively.