Copper nanoclusters-coated BSA as a novel fluorescence sensor for sensitive and selective detection of mangiferin

摘要

In this paper we report for the first time a fluorescence nanosensor for the detection of trace amount of mangiferin (MGF) by using bovine serum albumin (BSA)-protected copper nanoclusters (CuNCs@BSA). The CuNCs@BSA have an average size of 1.4 ± 0.2 nm and show a blue emission at 640 nm. Fluorescence emission of CuNCs@BSA was quenched in the presence of MGF providing a fluorescence responsive probe in a linear range of 3-180μM with a detection limit of 210 nM calculated at a signal-to-noise ratio of 3. The CuNCs@BSA show high photostability, since after 50 min of irradiation, only a fluorescence decrease of 15% is appreciated. Interference and competition studies indicate that the nanoprobe presents good selectivity over other relevant molecules including flavonoids and metal ions. These results confirmed that the nanosensor has high selectivity towards MGF in the presence of other substances. In addition the mechanism of sensitive fluorescence quenching response of CuNCs@BSA to MGF has been discussed. The sensor was then applied to the analysis of MGF in African mango extract and satisfactory recoveries were obtained indicating a good accuracy and reproducibility of the fluorescence nanosensor for detection of MGF. The proposed sensor is simple, rapid, and cost-effective demonstrating great potential for the determination of MGF in real samples.