A Nanomaterial-Based Biosensor for the Quantitative Detection of Enrofloxacin Residues in Raw Chicken

Highlights A nanobiosensor was developed for rapid detection of enrofloxacin residues in chicken meat. 5-Sulfosalicylic acid was adopted in a facile method for pretreatment of chicken meat samples. The detection limit of 14.1 µg kg -1 was below the maximum residue limit for chicken meat. The total detection time from sample pretreatment to result report was less than 1.5 h. Abstract . Antibiotic residues in animal-derived food products have been identified as a potential hazard in human health. Hence, a rapid, simple, and cost-effective method for detection of antibiotics in the food supply chain is highly desirable. The objective of this study was to develop a nanomaterial-based biosensor using immunomagnetic beads (IMBs) and quantum dots (QDs) for rapid and sensitive detection of enrofloxacin (ENR) residues in raw chicken. A 5-sulfosalicylic acid-based pretreatment method was adopted to extract ENR from chicken meat and reduce non-specific adsorption caused by complex food matrices. Two sensing elements were designed and fabricated: antibody functionalized IMBs and ENR-bovine serum albumin (BSA) conjugates modified QDs (QDs-BSA-ENR). Target ENR in samples was first captured and separated by IMBs, and then QDs-BSA-ENR, serving as a competitor and detection probe, was used to react with the residual binding sites on the IMB surfaces. With the presence of captured ENR, the binding of QDs-BSA-ENR to IMBs was competitively inhibited. Finally, the fluorescence intensity of reporting QDs in the QDs-BSA-ENR-IMBs complex at a wavelength of 614 nm was measured for the quantitation of target antibiotics. Under the optimum conditions, the proposed method allowed sensitive detection of ENR in a linear range from 1 to 100 ng mL-1 with a limit of detection (LOD) of 0.94 ng mL-1. The LOD for spiked chicken meat was 14.1 µg kg-1, which was below the maximum residue limits (MRLs) regulated in China and the European Union. The whole analytical procedure from food sampling to result report could be finished in less than 1.5 h. This nanobiosensor showed high potential for rapid and low-cost detection of ENR residues in the poultry supply chain to enhance food safety. Keywords: Enrofloxacin, Immunomagnetic beads, Nanobiosensor, Poultry, Quantum dots, Rapid detection.