title: Molecularly imprinted photonic crystals for the direct label-free distinguishing of L-proline and D-proline.
abstract: Novel molecularly imprinted photonic crystals (IPCs) for the highly sensitive label-free detection of L-proline and for the chiral recognition of L/D-proline were reported. A series of L-proline imprinted polyacrylamide photonic crystals (PAM-LPIPCs) and poly(acrylamide-co-acrylic acid) photonic crystals (PAM-co-AA-LPIPCs) were fabricated via the in situ polymerization of polystyrene opal. The PAM-LPIPCs exhibit good molecular response in L-proline solutions and can be visualized by the naked eye much like a pH test paper. The concentration of imprinted molecules (L-proline) in aqueous solution can be detected by the chromatic signal (structural color) or the optical signal (λmax). Furthermore, the responsivity and sensitivity of the PAM-co-AA-LPIPCs can be improved by increasing the amount of the imprinted content or the proportion of AA, or by decreasing the ratio of the cross-linking agent. When all these factors were balanced, a PAM2-co-AA0.4-LP0.5 IPC with good strength, high responsivity, high sensitivity and specific molecular recognition was obtained. It is found that the presented crystals can show obvious response to L-proline solution even at a low concentration of 1%. The PAM2-co-AA0.4-LP0.5 IPC not only very selectively distinguishes between L-proline and nicotinic acid, but it is also good at chiral recognition between L-proline and D-proline. What is more, the response is rapid and reversible and the IPC is recyclable.
authors.affiliation: Tianjin Huanhu Hospital, Tianjin 300060, PR China.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zeng
authors.initials: Z
authors.lastname: Pan
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Yuan
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Sun
authors.forename: Junkui
authors.initials: J
authors.lastname: Ma
authors.forename: Guanbo
authors.initials: G
authors.lastname: Huang
authors.forename: Fubao
authors.initials: F
authors.lastname: Xing
authors.forename: Jianping
authors.initials: J
authors.lastname: Gao
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D003102:Colloids / Q000737:chemistry; D057230:Limit of Detection; D054802:Molecular Imprinting; D015394:Molecular Structure; D017785:Photons; D011137:Polystyrenes / Q000737:chemistry; D011392:Proline / Q000737:chemistry*; D013194:Staining and Labeling; D013237:Stereoisomerism
chemical_list: D003102:Colloids; D011137:Polystyrenes; D011392:Proline