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 CsPbBr3 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 mu g/L for DDVP, and detection limit was 1.27 mu g/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.