Construction of fluorescent copper nanoclusters for selective sensing Fe 3+ in food samples based on absorption competition quenching mechanism

Facile fabrication of copper nanoclusters (CuNCs) with excellent fluorescence is desirable, but remains challenging and scarce for sensing applications in food. In this work, albumin egg (AE) stabilized CuNCs were prepared by a self-assembly templated method. The obtained fluorescent AE-CuNCs exhibited a strong emission at 412 nm upon excitation at 325 nm. Based on the absorption competition quenching mechanism, the AE-CuNCs fluorescent probe for Fe 3+ was developed. The probe had good linearity (0.10–1000 µM) with R 2 (0.986), low limits of detection (30 nM) and good selectivity. Furthermore, the iron content in noodles, biscuits, light soy sauce and bean sprouts was successfully determined by the fluorescent probe. Graphical Abstract