Nitrogen-doped graphene quantum dots coated with molecularly imprinted polymers as a fluorescent sensor for selective determination of warfarin

Abstract

Water-soluble and eco-friendly nitrogen-doped graphene quantum dots (NGQDs) were synthesized via a hydrothermal method. Subsequently, a novel optical sensor based on NGQDs coated with molecularly imprinted polymers (NGQDs@MIPs) was prepared via sol–gel polymerization. The synthesized polymers were characterized by transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The NGQDs@MIPs sensor showed specific selectivity and superior detection performance for warfarin which is a common anticoagulant rodenticide in environmental samples. The fluorescence intensity of the NGQDs@MIPs sensor presented an excellent linear response with warfarin concentrations ranging from 0.63 μM to 10 μM with a 0.16 μM detection limit. The recovery of warfarin from spiked environmental samples varied from 94.38% to 105.84%, with a relative standard deviation of less than 5.0%. Therefore, the NGQDs@MIPs sensor with a selective response and remarkable anti-interference performance may be a feasible method for the rapid detection of warfarin in environmental samples.