Nanomaterial-based fluorescent biosensors for veterinary drug detection in foods

Veterinary drugs have been widely used in the food industry. Their residues in food products need to be tightly regulated to ensure food safety. In particular, some veterinary drugs are still used illegally, although they have already been banned. Nanomaterials are playing an increasingly important role in analytical chemistry due to their unique properties. Compared to traditional organic dyes and colloidal gold nanoparticle labels, fluorescent nanomaterials appear particularly attractive for the detection of veterinary drug residues. This review summarizes recent advancements of fluorescent biosensors using nanomaterials for the detection of veterinary drug residues in foods. The useful properties of each type of fluorescent nanomaterial are first discussed such as large Stokes shifts, long emission lifetime, and high quantum yields, which are useful for detection in food-related sample matrix. The following target recognition molecules are then reviewed individually including antibodies, aptamers, molecularly imprinted polymers, and metal ion coordination based ligands. Representative bioconjugation and assay methods are discussed for each recognition mechanism. Finally, a few future research directions are outlined in the last section of this review.