title: Molecularly imprinted photonic hydrogels as colorimetric sensors for rapid and label-free detection of vanillin.
abstract: A novel colorimetric sensor for the rapid and label-free detection of vanillin, based on the combination of photonic crystal and molecular imprinting technique, was developed. The sensing platform of molecularly imprinted photonic hydrogel (MIPH) was prepared by a noncovalent and self-assembly approach using vanillin as a template molecule. Morphology characterization by scanning electron microscope (SEM) showed that the MIPH possessed a highly ordered three-dimensional (3D) macroporous structure with nanocavities. The vanillin recognition events of the created nonocavities could be directly transferred into readable optical signals through a change in Bragg diffraction of the ordered macropores array of MIPH. The Bragg diffraction peak shifted from 451 to 486 nm when the concentration of the vanillin was increased from 10⁻¹² to 10⁻³ mol L⁻¹ within 60 s, whereas there were no obvious peak shifts for methyl and ethyl vanillin, indicating that the MIPH had high selectivity and rapid response for vanillin. The adsorption results showed that the hierarchical porous structure and homogeneous layers were formed in the MIPH with higher adsorption capacity. The application of such a label-free sensor with high selectivity, high sensitivity, high stability, and easy operation might offer a potential method for rapid real-time detection of trace vanillin.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors.forename: Hailong
authors.initials: H
authors.lastname: Peng
authors.forename: Shenqi
authors.initials: S
authors.lastname: Wang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Xiong
authors.forename: Jinhua
authors.initials: J
authors.lastname: Li
authors.forename: Lingxin
authors.initials: L
authors.lastname: Chen
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Li
mesh_terms: D001547:Benzaldehydes / Q000032:analysis*; D003124:Colorimetry; D005421:Flavoring Agents / Q000032:analysis*; D005503:Food Additives / Q000032:analysis*; D005504:Food Analysis; D020100:Hydrogels; D036103:Nanotechnology; D055095:Optics and Photonics / Q000379:methods
chemical_list: D001547:Benzaldehydes; D005421:Flavoring Agents; D005503:Food Additives; D020100:Hydrogels; C100058:vanillin