Microcavity Fiber SERS Probe Coated With Ag Nanoparticles For Detecting Antibiotic in Milk

In this paper, an Ag nanoparticles (AgNPs) modified multimode fiber (MMF) SERS probe prepared based on sol self-assembly method is proposed and fabricated. Different fiber SERS probes (AgNPs-MMF-x, x is the self-assembly time) are obtained by adjusting the self-assembly time. Using rhodamine 6G (R6G) solution as the probe molecule, the far-end performances of the prepared fiber SERS probe are studied, and the AgNPs-MMF-30 probe with obvious advantages in SERS performance is obtained. The limit of detection (LOD) for R6G is as low as 10 −9 M, demonstrating the high sensitivity of AgNPs-MMF-30 probe. The enhancement factor (EF) of AgNPs-MMF-30 probe to 10 −7 M R6G is about 1.36 × 10 8 . In addition, the AgNPs-MMF-30 probe has an outstanding reproducibility across the entire area with the maximum value of relative standard deviation (RSD) of less than 10.94%. The AgNPs-MMF-30 probe exhibit a long-term stability regarding Raman enhancement of up to 35 days. Importantly, the high-performance AgNPs-MMF-30 probe is further applied as a highly sensitive SERS platform for the trace detection of antibiotic in milk. The fiber SERS probe has the characteristics of fast, effective, remote real-time detection and so on, so it has great potential application in biochemical sensing and food security.