Rapid detection of fluoroquinolone antibiotic residues in poultry feathers via liquid–liquid microextraction combined with surface-enhanced Raman spectroscopy

Fluoroquinolones are widely used in poultry, and misuse can leave residues; conventional live–poultry testing is time–consuming and labor–intensive, motivating rapid, sensitive screening. We present a rapid LLME–SERS method for detecting fluoroquinolone residues in poultry feathers. Gold nanorods were synthesized by a seed–mediated route and characterized by UV–Vis spectroscopy and SEM. Norfloxacin and danofloxacin mesylate were extracted by liquid–liquid microextraction and analyzed using the Au nanorod sol as the SERS substrate. The method detects low concentrations in standards with a 1 µg mL⁻¹ limit of detection, and in spiked feather extracts with 10 µg mL⁻¹ for both analytes. The protocol is fast (∼5 min), solvent–efficient, and affords detection limits comparable to HPLC-MS/MS and immunoassays. The proposed method offers a rapid, facile, and highly sensitive approach for detecting fluoroquinolone antibiotic residues in poultry feathers. While ensuring the safety of poultry food products, this approach provides on-site preliminary screening technical support for quality control.