A label-free Eupatorium odoratum L. CQDs-based fluorescence sensor as a “turn-on” type for effective detecting of artificial sweetener

Artificial sweetener needs to control the maximum dosage, such as aspartame, cyclamate, saccharin sodium, and sucralose, are mainly used in fruits, jams, beverages, desserts, and dairy products. In this research, a novel label-free fluorescent sensor based on carbon quantum dots (CQDs) were prepared by a one-step hydrothermal method using Eupatorium odoratum L . , as a highly sensitive “turn-on”-type fluorescent probe for the detection of artificial sweetener. They exhibit photoluminous emission at 444 nm under 370 nm excitation, with a quantum yield of 20.36%. Under optimal conditions, the standard curve of aspartame, neotame, and sucralose had good linearity in the concentration range of 0–750 µmol/L, 0–400 µmol/L, and 100–800 µmol/L, respectively, and the linear correlation coefficients were 0.9913, 0.9978, and 0.9974. The CQDs were also shown to selectively react with aspartame, neotame, and sucralose, leading to fluorescence enhancing effect, and low limits of detection were 4.2383 µmol/L, 6.8834 µmol/L, and 7.6576 µmol/L, respectively, which were much lower than the limits of detection for aspartame (1.0194–33.9789 mmol/L), neotame (26.4229–792.6861 µmol/L), and sucralose (0.3772–12.5745 mmol/L) in various foodstuffs as stipulated in GB 2760-2014. The results indicated our developed sensor based on E. odoratum L . CQDs has great application prospects for artificial sweeteners detection.