One-step synthesis of orange fluorescent copper nanoclusters for sensitive and selective sensing of Al3+ ions in food samples

One-step approach was developed for the fast synthesis of copper nanoclusters (CuNCs), which were used as a fluorescent probe for the sensitive detection of Al 3+ in food samples. For this, aqueous CuSO 4 was reduced into CuNCs by dithiothreitol (DTT) at room temperature within 30   min. The synthetic process was fast, simple and easy. The DTT-capped CuNCs (DTT-CuNCs) were characterized by UV–vis absorption, fluorescence, FT-IR, TEM and XPS. The DTT-CuNCs display orange fluorescence with a maximum emission at 590   nm while excitation at 360   nm. The aggregation-induced fluorescence enhancement property of DTT-CuNCs in presence of Al 3+ was found. On this basis, we developed a simple, sensitive, selective turn-on fluorescent sensor for the detection of Al 3+ in food samples. Under the optimized conditions, the enhanced fluorescence intensity exhibited a good linear relationship with Al 3+ concentrations in the range from 0.01   μM to 7   μM with a detection limit of 0.01   μM. The DTT-CuNCs-based fluorescent probe has been successfully used to assay the content of aluminum in real food samples such as the fried food and pasta. These results demonstrate the great potential of the DTT-CuNCs-based fluorescence sensor for the routine estimation of Al 3+ content in food samples.