Molecularly Imprinted Photonic Polymers For Amino Acids Chiral Sensing

The incorporation of molecularly imprinted materials into photonic crystals,which is named molecularly imprinted photonic polymer, is an ideal sensing platformwherein analyte recognition and an analyte-dependent transduction methodology aresimultaneously realized. When molecularly imprinted photonic polymers recognizethe imprinted molecules, the volume of imprinted polymers will continuously changewith the changes of the external environment. At the same time, the modulation of thephotonic crystal lattice parameter leads to a change of the Bragg diffraction peak,which results in a color change of the imprinted polymers that can be observe bynaked eyes. The change of diffraction peak can be measured by fiber opticspectrometer in order to achieve the quantitative determination for the analytes.In the present work, L-pyroglutamic acid imprinted photonic polymers have beenprepared by using different functional monomers and polymerization modes. Thechiral and non-chiral recognition of glutamate were studied by investigating itsselectivity and sensitivity using the intelligent molecularly imprinted photonicpolymer as sensor.The main content are as follows：1. L-pyroglutamic acid imprinted photonic polymers were thermally polymerizedwith acrylamide and methyl methacrylate. The selectivity of the imprinted photonicpolymers to the imprinted molecular has been studied. It was found the molecularlyimprinted sensor has a very good selectivity for L-pyroglutamic acid when comparedto D-pyroglutamic acid, L-phenylalanine, L-threonine and L-alanine. Linearrelationship was found between the Δλ and the concentration of imprinted molecule,and a color change of the imprinted polymers can be observed by naked eyes. Theconcentration of L-pyroglutamic acid in monosodium glutamate samples was detectedusing such imprinted polymers.2. Thermopolymerization and photopolymerization methods were used forpreparation of L-pyroglutamic acid imprinted photonic polymers with N-isopropylacrylamide and methyl methacrylate. By examining the chiral recognition ability ofimprinted materials to L-pyroglutamic acid, it was found that photopolymerizationmethod was more suitable for preparation of imprinted photonic polymers thanthermopolymerization method. With the increase of imprinted moleculesconcentration, obvious redshift of Bragg diffraction peaks was observed while the change of its controlled enantiomers and non-enantiomer was not obvious.