Fluorescence Nanobiosensor for Simultaneous Detection of Multiple Veterinary Drugs in Chicken Samples

Some veterinary drug residues in food products and environment have been widely regarded as severe threats to human health. Rapid and simultaneous detection methods are crucial to monitor and control veterinary drug usage. Here, we propose a fluorescence biosensor utilizing immunomagnetic beads(IMBs) and quantum dots(QDs) for the rapid and simultaneous detection of 1-adamantylamine(ADA), enrofloxacin(ENR) and tilmicosin(TIL) in raw chicken meat. A pretreatment method using sodium phosphotungstate–magnesium as extraction reagent was developed to simultaneously extract ADA, ENR and TIL from chicken meat with minor interference in background or response. By adding the IMBs modified with three types of antibodies and the QD-antigens modified with three types of BSA-antigens to sample, IMBs competitively conjugated to target antigens in a sample or QD-antigens. After magnetic separation, the residual QD-antigens were adopted to collect signals using fluorescence spectroscopy. Using QDs with well separated emission peaks, the detection of one type of targets was minorly interfered by the others. Under the optimum conditions, the biosensor exhibited the limit of detection of 0.96,3.32, and 3.17 ng/mL for ADA, ENR and TIL in chicken samples, respectively, as well as good specificity. Due to the way of direct collection of signals in extracts, the tedious and complicated multiple magnetic separation and signal amplification procedures in conventional methods were avoided, thus the procedures were significantly simplified, and the reduction of the operation time of 30 min for sample pretreatment and 40 min for detection part was achieved. The biosensor might be promising in the rapid, in-field and sensitive screening of multiple veterinary drugs to ensure agriculture and food safety.