A ratiometric fluorescent probe based on Lu-Eu-DPA nanoparticles for sensitive and visual detection of gentamicin sulfate, neomycin, and erythromycin in food

The overuse of antibiotics leads to significant health risks and environmental challenges. Therefore, selective and sensitive detection of antibiotic residues is a critical issue. Here, a double-emission ratiometric fluorescence probe (Lu-Eu-DPA) was constructed for the selective detection of gentamicin sulfate (GEN), neomycin (NEO), and erythromycin (EM). The Lu-Eu-DPA coordination polymer nanoparticles composed of luminol, the coordinated nuclear metal Eu 3+ , and 2,6-pyridinedicarboxylic acid (DPA). The coordination reaction between luminol molecules and Eu 3+ ions produce the aggregation-induced emission (AIE) effect, while DPA acts as a ligand for the antenna, absorbing energy from the excitation light and then transferring the energy to Eu 3+ . Based on the AIE effect and antenna effect (AE), the fluorescence intensity of Lu-Eu-DPA at 426 nm and 617 nm was correlated with the concentration of GEN, NEO, and EM, and the detection limits of GEN, NEO, and EM were 20, 25, and 48 nmol/L, respectively. The detection capability of the proposed method in pork samples was also studied. In addition, semi-quantitative determination of GEN, NEO, and EM was conveniently and efficiently performed using a smartphone-based visualization method. These results suggested that this probe with good selectivity and specificity was a promising method for swiftly detecting multiple antibiotic residues.