Molecularly imprinted mesoporous silica embedded with perovskite CsPbBr3 quantum dots for the fluorescence sensing of 2,2-dichlorovinyl dimethyl phosphate

The preparation of molecularly imprinted mesoporous silica with perovskite quantum dots (QDs) grown in situ and their applications for highly sensitive fluorescence sensing of 2,2-dichlorovinyl dimethyl phosphate (DDVP) is presented. Highly ordered mesoporous silica materials were synthesized and employed as solid supports. Uniform and highly luminescent CsPbBr 3 QDs were grown in the pores of these mesoporous silica. Subsequently, surface graft imprinting was applied on the surface of the QDs-encapsulated mesoporous silica. The QDs were acted as a recognition signal transducer and the molecular imprinting process provided recognition sites for 2,2-dichlorovinyl dimethyl phosphate. The QDs grown in situ in SBA-15 mesopores greatly improved the sensitivity for the determination of 2,2-dichlorovinyl dimethyl phosphate. Under the optimized conditions, the QDs-encapsulated molecularly imprinted mesoporous silica was linear between the concentration of 5 and 25 μg/L for DDVP, and detection limit was 1.27 μg/L. The QDs-encapsulated molecularly imprinted mesoporous silica was subsequently applied to the fluorescence analysis of 2,2-dichlorovinyl dimethyl phosphate in cabbage and lettuce samples and achieved recoveries from 87.4% to 101%. The time-resolved photoluminescence decay and UV–vis spectroscopic studies indicated that the quenching mechanism on the fluorescence of the QDs can be attributed to charge transfer between the QDs and DDVP.