Rapid determination of isepamicin by using SERS based on BSA-protected AgNPs modified by α-Fe₂O₃

A surface-enhanced Raman spectroscopy (SERS) method for the determination of isepamicin (ISE) using silver nanoparticles (AgNPs) protected by bovine serum albumin (BSA) and modified by α-Fe₂O₃ as an efficient substrate was established. The synthesized substrate was characterized and verified by transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV-vis), and fourier transform infrared spectroscopy (FT-IR). The conditions affecting the Raman signal of ISE were optimized by single factor and response surface experiments. Under optimized conditions, a standard curve I_SERS = 43.08c + 63598.69 (c: nmol/L) with a linear relationship (r = 0.9976) was established between the SERS intensity and ISE concentration in the range of 20.00 - 2000.00 nmol/L. The limit of detection (LOD) for ISE was 16.58 nmol/L (S/N = 3). The recovery of ISE in the samples was 96.29 % - 104.12 %, with relative standard deviation (RSD) was 1.53 % - 3.43 % (n = 5). The SERS method was reliable and satisfactory for the quantitative analysis of ISE at low concentration.