A molecular imprinting fluorescence sensor based on quantum dots and a mesoporous structure for selective and sensitive detection of 2,4-dichlorophenoxyacetic acid

[Display omitted] •The combination of selective molecularly imprinted polymers (MIPs) and mesoporous imprinted microspheres with fluorescent quantum dots (QDs) was employed for the determination of 2,4-dichlorophenoxyacetic acid (2,4-D).•SiO2@QDs@m-MIPs have uniform spherical shapes and excellent dispersibility in water.•This facile, novel and efficient approach used a sensitive fluorescent nanosensor for 2,4-D detection in real bean sprout samples.•The obtained SiO2@QDs@m-MIP-based sensor demonstrated simplicity, rapidity and universality, high selectivity and sensitivity, good reliability and practicability. A novel molecular imprinting fluorescence sensor was constructed by anchoring mesoporous structured imprinting microspheres on the surfaces of quantum dots (QDs) surface for the selective and sensitive detection of 2,4-dichlorophenoxyacetic acid (2,4-D) on the basis of an electron-transfer-induced fluorescence quenching mechanism. The resulting sensor was well characterized and had ideal spherical morphology and fluorescence properties. Under the optimized conditions, the sensor exhibited a satisfactory linearity within 0.66–80μM, with a low detection limit of 2.1nM within 20min. The sensor was successfully applied for the detection of 2,4-D in bean sprout samples, and high recoveries at three spiking levels of 2,4-D, ranging from 95.0 to 110.1%, with precisions below 4.9%, were attained. By taking advantage of surface imprinting and QDs, the sensor exhibited high sensitivity and good selectivity for the separation, enrichment and detection of 2,4-D in real food samples, thereby ensuring food safety.