Molecular imprinting-based fluorescent optosensor using a polymerizable 1,8-naphthalimide dye as a florescence functional monomer

Abstract

A molecular imprinting-based fluorescent optosensor (FMIPs) was developed based on N-allyl-4-ethylenediamine-1,8-naphthalimide as a fluorescent functional monomer in order to study the selective recognition of caffeine as a model drug. The photo physical characteristics of dye and its imprinting polymer in solution and solid form were investigated in the presence of caffeine. The sensing principle was also discussed. Fluorescence emissions of synthesized FMIP as well as monomer dye were ‘switched off’ in the presence of target molecule based on PET mechanism. The relative intensity was linear against caffeine concentration from 1.94×10−6 to 1.94×10−4gml−1 with a detection limit of 1.22×10−6gml−1. The present FMIP sensor has been successfully applied to the determination of caffeine in real samples.