A novel and facile fluorescent artificial receptor on the basis of the molecularly imprinted polymer-coated graphene quantum dots was engineered successfully to detect colistin. The colistin imprinted graphene quantum dots (CMIP-GQDs) was synthesized by vinyl-based radical polymerization between functional monomers and crosslinker at around the template molecule on the surface of graphene quantum dots. The size of bare, CNIP-GQDs, and CMIP-GQDs was about 4.8 ± 0.6 nm, 18.4 ± 1.7 nm, and 19.7 ± 1.3 nm, respectively. The CMIP-GQDs, which showed the strong fluorescence emission at 440 nm with the excitation wavelength fixed at 380 nm, had excellent selectivity and specificity to rapidly recognize and detect colistin. The linear range of fluorescence quenching of this fluorescent artificial receptor for detection colistin was 0.016-2.0 μg mL-1 with a correlation coefficient (R2) of 0.99919, and the detection limit was 7.3 ng mL-1 in human serum samples. The designed receptor was successfully applied to detect colistin in human serum samples and it achieved excellent recoveries shifted from 93.8 to 105%. Graphical abstract.
Keywords: Artificial receptor; Colistin; Fluorescence quenching; Graphene quantum dot; Molecularly imprinted polymer.