Determination of parathion-methyl in vegetables by fluorescent-labeled molecular imprinted polymer

A novel sensor for the determination of parathion-methyl based on couple grafting of functional molecular imprinted polymers (MIPs) was fabricated which is developed by anchoring the MIP layer on surfaces of silica particles embedded CdSe quantum dots by surface imprinting technology. The synthesized molecular imprinted silica nanospheres (CdSe@SiO ₂@MIP) allow a high selectivity and sensitivity of parathion-methyl via fluorescence intensity decreasing when the MIP material rebinding the parathion-methyl molecule. Compared with the MIP fabricated in traditional method, the template of parathion-methyl was easier to remove from the CdSe@SiO ₂@MIP imprinted material. Under optimal conditions, the fluorescence intensity of parathion-methyl at the imprinted sensor was detected by spectrofluorophotometer. The relative fluorescence intensity of CdSe@SiO ₂@MIP decreased linearly with the increasing concentration of parathion-methyl ranging from 0.013 mg·kg ^-1 to 2.63 mg·kg ^-1 with a detection limit (3σ) of 0.004 mg·kg ^-1 (S/N=3), which is lower than the MIP in tradition. The imprinted film sensor was applied to detect parathion-methyl in vegetable samples without the interference of other organophosphate pesticides and showed a prosperous application in the field of food safety.