Synthesis of Recognition Matrix from 4-Methylamino-N-Allylnaphthal-Imide with Fluorescent Effect for the Imprinting of Creatinine

4-Methylamino-N-allylnaphthalimide (4-MAANI), a functional monomer with fluorescent effect, was synthesized for the imprinting and specific uptake of creatinine, an important clinical marker for kidney function. 4-Methylamino-N-allylnaphthalimide was synthesized from the reaction of 4-bromo-1,8-naphthalic anhydride with allylamine to form 4-bromo-N-allylnaphthalimide and further to react with methylamine. Excitation and emission of the fluorescent monomer was investigated by both a three-dimensional plot of fluorescent intensity versus excited and emitted wavelengths and a corresponding contour plot. The photoluminescence properties of the as-prepared conjugated species were also studied. 4-Methylamino-N-allylnaphthalimide (4-MAANI) fluorescent monomer, methacrylic acid (MAA) functional monomer, ethylene glycol dimethylacrylate (EGDMA) cross-linker, and 2,2'-azobisisobutyronitrile (AIBN) initiator were then utilized in the presence of creatinine template for the processing of heat-induced polymerization. FT-IR analysis was used to confirm the successful synthesis of 4-MAANI. The specific recognition cavity for creatinine was then created from the polymer matrix after the removal of creatinine by proper solvent. The imprinting effect as well as selectivity from the creatinine containing mixture was also evaluated. The grouped clusters from the emitted fluorescent intensities of the imprinted and nonimprinted polymers before and after rebinding of creatinine were obtained and discussed. Serum spiked with a different concentration of creatinine was also used to confirm the feasibility of clinical applications in the future. Successful recognition of the creatinine molecule via the combined effect of molecular imprinting and photoluminescence of the imprinted polymeric material was thus confirmed in this work.