Sensitive and visual determination of sulfamethazine in milk and drinking water using aggregation-induced emission fluorescent sensor based on luminol-europium nanocomposites

Considering the excessive residue and serious harm of sulfamethazine (SM 2 ), the sensitive determination of SM 2 has attracted wide attention in ensuring food security and human health. Herein, using the unique fluorescence property of aggregation-induced emission (AIE), we reported a simple and sensitive detection approach of SM 2 residues in milk and drinking water. Firstly, luminol-europium nanocomposites (luminol-Eu NCs) were self-assembly synthesized via AIE strategy. Then, the fluorescence emission of luminol-Eu NCs could be quenched by SM 2 due to the inner filter effect (IFE). As a result, the fluorescent sensor based on luminol-Eu NCs displayed a wide linear response for SM 2 in a concentration range of 0.1–500 µmol/L and a detection limit of 90 nmol/L was obtained. Furthermore, semi-quantitative detection of SM 2 on test papers was realized via a smartphone-assisted visual sensing device. Therefore, this fluorescent sensor shows a potential value in the field of food safety assessment. Graphical abstract An aggregation-induced emission fluorescent sensor based on luminol-europium nanocomposites was developed and applied for sensitive and visual detection of sulfamethazine in milk and drinking water.