Highly sensitive fiber optic SERS probes based on semiconductor and precious metal materials

Combining the advantages of semiconductors and precious metals to produce highly sensitive Surface-enhanced Raman scattering (SERS) substrates. In this paper, Cu₂O@Ag core-shell particles were prepared, optical fibers were selected as substrates to strengthen the portability of SERS substrates, optical fiber SERS probes were prepared by electrostatic adsorption method and chemical bonding method, and the performance of SERS probes prepared by the two methods under the same deposition time was discussed, which it was found that the optical fiber probes prepared by chemical bonding method had better Raman enhancement effect. Rhodamine 6G(R6G) was used as the detection molecule to investigate the detection limit, uniformity, reproducibility of fiber SERS probe. 4-nitrophenyl thiophenol (4-NTP) is an organic molecule used in the synthesis of pesticides and dyes, excessive use can be harmful, it was found that the detection concentration of 4-NTP is as low as 10^-6 M, and the detection limit of the optical fiber SERS probe is used to detect thiram in pears, which its detection limit is 0.5 mg/L, which is far lower than the national standard of the United States and China (5 mg/L). The above experimental results show that an excellent fiber optic SERS probe has been successfully developed.