A molecular imprinted fluorescence sensor based on carbon quantum dots for selective detection of 4-nitrophenol in aqueous environments

P-nitrophenol (4-NP) is the most persistent and highly toxic species among nitrophenol. In this work, a novel fluorescent probe for the detection of 4-NP in aqueous environment was constructed by combining the carbon dots (CQDs) with excellent optical properties and the molecularly imprinted polymer (MIP) with favorable selectivity . The CQDs were synthesized by hydrothermal method using citric acid hydrate as carbon source and o -phenylenediamine as surface modifier, then the molecularly imprinted polymers coating on the CQDs (MIP@CQDs) were obtained by sol-gel imprinting process. The fluorescence quenching of MIP@CQDs is the results of internal filtration effect and dynamic quenching when they encounter with 4-NP. The probe is suitable for the quantitative detection of trace 4-NP in actual aqueous samples, such as tap water , wastewater and seawater, with satisfying recoveries from 95.1 % to 107.8 %, wide detection linear ranges between 0 and 144 μmol/L, low detection limit of 0.41 μmol/L and high selectivity. The detection results are consistent with those of the HPLC method. This work provides a simple, rapid and effective fluorescent detection method for trace 4-NP in aqueous environment.