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

Abstract

Aflatoxin B1 (AFB1) 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 AFB1 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 AFB1 concentrations, the proposed fluorescent sensor had an excellent selectivity for AFB1 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 AFB1 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 AFB1 detection in agricultural products.