Fluorescent molecularly imprinted polymer sensor prepared using mesoporous silica as carrier for selective detection of bisphenol A.

A fluorescent molecularly imprinted polymer (FMIP) sensor for the selective detection of bisphenol A (BPA) was constructed based on surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization with mesoporous silica (mSiO2) as the carrier. N-allyl-4-ethylenediamine-1, 8-naphthalimide was used as the fluorescent functional monomer, with mSiO2 as the carrier. The high specific surface area of the mSiO2 carrier provides more imprinting sites for the FMIP, thereby effectively enhancing the recognition efficiency of the resulting imprinted polymer. Azide groups were initially grafted onto the mSiO2 surface. Subsequently, an alkynyl-functionalized RAFT agent was introduced via a copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The FMIP was then synthesized by RAFT polymerization using BPA as the template and methacrylic acid (MAA) as the functional monomer. Upon rebinding of the template BPA to the imprinting cavities, the fluorescence of the MIP-capped N-allyl-4-ethylenediamine-1, 8-naphthalimide was efficiently quenched. The ratio of fluorescence intensity exhibited a linear response to the concentrations of BPA ranging from 5 to 80 µM, with a detection limit of 0.43 µM. Moreover, the FMIP sensor was successfully applied to detect BPA in real samples, with recoveries ranging from 96.55% to 102.25% and relative standard deviations (RSDs) of 0.4%-1.57%. The results indicate that the prepared FMIP sensor shows great potential for the detection of BPA in environmental media.