Rapid determination of marbofloxacin by surface-enhanced Raman spectroscopy of silver nanoparticles modified by β-cyclodextrin

A novel surface enhanced-Raman spectroscopy (SERS) assay for marbofloxacin was developed based on β-cyclodextrin-modified silver nanoparticles (β-CD-AgNPs). The marbofloxacin could interact with β-CD-AgNPs and a new assembly was formed by AgN covalent bond. This assembly was characterized by the spectra of FT-IR and UV-vis. The optimal measurement conditions were studied in detail. In 0.033 mol L-1 HCl solution, marbofloxacin had a sensitive SERS signal at 806 cm-1. The enhancement factor (EF) was 2.11 × 107. There was a good linear correlation between the concentration of marbofloxacin and SERS intensity: the linear range was 0.003-0.03 μmol L-1 (r2 = 0.996). The limit of detection (LOD) (S/N = 3) was 1.7 nmol L-1 (S/N = 3). Moreover, the influence of some interferences including Cu2+, K+, Zn2+, Ca2+, Na+, Mg2+, glucose and tiamulin on the determination were studied. The developed SERS method was used to detect the content of marbofloxacin in chicken and duck, the recovery was 101.3%-103.1% with RSD 4.07%-6.83%.