Utilizing fluorescein methacrylate as fluorescent functional monomer on synthesizing fluorescent molecularly imprinted polymer in sensing caffeine

In this study describes the fluorescein methacrylate (FMA) used as fluorescence functional monomer in the synthesis of caffeine-imprinted fluorescence polymers (Caf-FMIP) for the selective recognition of caffeine. The Caf-FMIP was synthesized using bulk polymerization with non-covalent imprinting approach and the formation of ˗NH groups had interaction with caffeine and FMA moieties was confirmed by using Fourier transform infrared spectroscopy (FT-IR). The absorption isotherm analysis of Caf-FMIP favors Freundlich model suggested the forming heterogeneous surface was occurred due to non-covalent imprinting approach. Fluorescence emissions of synthesized Caf-FMIP were ‘switched on’ in the presence of target molecule based on photo-induce electron transfer (PET) mechanism. In addition, Caf-FMIP fluorescence was enhanced more strongly by caffeine compared to non-imprinted polymer, which indicated that caffeine could recognized by the Caf-FMIP selectively.