Determination of spectinomycin by SERS based on BSA-protected AgNPs decorated with α-CD

Abstract

A surface-enhanced Raman scattering (SERS) spectroscopic method with good selectivity and high sensitivity for the determination of spectinomycin (SPT) was established based on silver nanoparticles (AgNPs) coated by bovine serum albumin (BSA) and decorated with α-cyclodextrin (α-CD). The SERS characteristic peak of SPT at 485 cm−1 was selected for quantity analysis and the enhancement factor (EF) of the detection system was 1.95 × 107. The synthesis of α-CD/Ag@BSA NPs substrate was characterized by ultraviolet visible (UV–vis) spectroscopy and transmission electron microscope (TEM). The interaction between the substrate and the drug was demonstrated by UV–vis and fourier transform infrared (FT-IR) spectroscopy, which provided a theoretical basis for the determination of SPT by SERS. The effects of experimental parameters such as α-CD/Ag@BSA NPs solution volume, NaCl volume and mixing time on SERS signal intensity were investigated. Under the optimum conditions, the determination of SPT by SERS performed a good linear relationship in the 3.33 – 1000.00 nmol L−1 concentration range for SPT (ISERS = 131.52c + 26585.53, c: nmol L−1, r = 0.996). Limit of detection (LOD) for SPT was 2.01 nmol L−1 (S/N = 3). The effects of various interfering ions and similar drug on the determination system were studied. The SERS method was successfully applied to the determination of SPT in beef and lamb samples. The relative standard deviation (RSD) of SPT in the samples was 2.27% – 4.82% (n = 5), with recovery 96.04% – 104.90%.