Rapid detection of multiple antibiotics in chicken samples via a fluorescence nanobiosensor coupled with a homemade fluorescence analyzer

Abstract

Antibiotic residues in foods pose a serious threat to human health. However, routine analysis techniques require bulky laboratory instruments and skilled personnel or give single-channel analysis results, exhibiting low practicality. Here, we explored a rapid and easy-to-use detection system combining a fluorescence nanobiosensor with a homemade fluorescence analyzer for the simultaneous identification and quantification of multiple antibiotics. The nanobiosensor assay worked based on the targeted antibiotics competing with signal labels of antigen-quantum dots (IQDs) to bind with recognition elements of antibody-magnetic beads (IMBs). The fluorescence signals of IMB-unbound IQDs in a magnetically separated supernatant, related to antibiotic concentration, were automatically collected and processed by our self-designed and homemade fluorescence analyzer which integrated mechanical control hardware (consisting of a mechanical arm, a ten-channel rotary bench, and an optical detection unit) and user control software (installed on a built-in laptop). The fluorescence analyzer enabled the analysis of 10 samples within 5 min in one round and permitted the real-time uploading of sample data to the cloud. By employing three QDs with emission wavelengths of 525 nm, 575 nm, and 625 nm, this multiplex fluorescence biosensing system demonstrated great sensitivity and accuracy for simultaneously analyzing enrofloxacin, tilmicosin, and florfenicol in chicken samples with detection limits of 0.34 μg kg⁻¹, 0.7 μg kg⁻¹, and 0.16 μg kg⁻¹, respectively. Moreover, the biosensing platform performed well in a wealth of chicken samples covering various breeds from three Chinese cities. This study identifies a generic and user-friendly multiplex biosensor platform with significant potential for use in food safety and regulation.