A novel fluorescent sensing platform based on nitrogen-doped carbon quantum dots for rapid and sensitive detection of aflatoxin B1 in corn flour

Aflatoxin B 1 (AFB 1 ) contamination in cereals and their products seriously concerns food safety and human health. Herein, a nitrogen-doped carbon quantum dots (N-CQDs)-based fluorescent sensing platform was successfully developed for the sensitive and rapid detection of AFB 1 in corn flour. In this work, using sodium citrate and urea as precursors, hydrophilic N-CQDs were synthesized by the one-step hydrothermal method with good biocompatibility and high fluorescence stability. The as-prepared N-CQDs exhibited excitation wavelength-independent fluorescence in the 300–370 nm range, and had bright blue emission at 448 nm upon 360 nm excitation. Via fluorescence quenching of the N-CQDs in the presence of increasing AFB 1 concentrations, the proposed fluorescent sensor had an excellent selectivity for AFB 1 detection with a low limit of detection (0.13 ng/mL) in the linear range of 0.5–100 ng/mL. Under optimized sensing conditions, the rapid AFB 1 determination in real corn flour samples was realized with good recoveries (95.3–105.7%). In summary, present results indicated the promising potential of this novel N-CQDs-based fluorescent sensor for rapid and effective AFB 1 detection in agricultural products.