A SERS-based immunochromatographic assay for ultrasensitive and quantitative detection of florfenicol using long wavelength absorption of Au nanocubes

An immunochromatographic assay (ICA) based on surface-enhanced Raman scattering (SERS) for ultrasensitive and quantitative detection of florfenicol (FF) in food samples was developed. Au nanocubers (AuNCs) with long wavelength absorption were synthesised, characterised and used as the substrate in SERS-ICA. Immunoprobe was prepared by linking Raman reporter and the antibody against FF on AuNCs. The SERS-ICA was completed in 15 min. By measuring the Raman intensities on T lines, quantitative detection of FF was achieved. The IC50 and limit of detection (LOD) of the assay for FF were 0.027 ng mL−1 and 0.12 pg mL−1, respectively. The cross-reactivity (CR) of the assay with thiamphenicol, chloramphenicol and other four drugs were examined. The recoveries of FF in spiked samples were 88.5% ∼ 102.4% with RSD of 2.3% ∼ 7.4%. It was proven that SERS-ICA was able to rapidly detect FF in food samples with high sensitivity, accuracy and precision.