Simple synthesis of fluorine-doped carbon quantum dots for fluorescence-based Amaranth quantification in food matrices

The detection of food pigments is essential for ensuring food quality and safety. This study presents the efficient preparation of fluorine-doped carbon quantum dots (F-CQDs) through a simple solvothermal reaction using Zanthoxylum and NH 4 F as precursors. The resulting F-CQDs displayed optimal fluorescence characteristics, along with a quantum yield of 4.81 %. Notably, the as-prepared F-CQDs exhibited excellent photostability and were effectively quenched by amaranth, demonstrating their potential as reliable probes for amaranth detection. The probe showed a strong linear response ( R 2  = 0.9992) to amaranth concentrations of 0.15–75 μM, yielding a limit of detection as low as 50 nM. Validation tests across various food matrices, including bayberry, a sugar-sweetened beverage, and candies, yielded good recovery rates of 89.0 %–119 % and a relative standard deviation of less than 4.9 % ( n  = 5), indicating high reliability. These findings suggest that F-CQDs are viable candidates for detecting amaranth in foods, which can help enhance food safety and quality control.