A visible-light-responsive azobenzene derivative, 3,5-dichloro-4-((2,6-dichloro-4-(methacryloyloxy)phenyl)diazenyl)benzoic acid, was synthesized and used as the functional monomer to fabricate a visible-light-responsive core-shell structured surface molecularly imprinted polymer (PS-co-PMAA@VSMIP). After removal of the sacrificial PS-co-PMAA core, a hollow structured surface molecularly imprinted polymer (HVSMIP) was obtained. Both the PS-co-PMAA@VSMIP and HVSMIP were used for the detection of chlorpyrifos, a moderately toxic organophosphate pesticide. They exhibited good visible-light-responsive properties (550 nm for trans→cis and 440 nm for cis→trans isomerization for an azobenzene chromophore) in ethanol/water (9:1, v/v). Compared with the PS-co-PMAA@VSMIP, the HVSMIP had a larger surface area, pore volume, binding capacity, imprinting effect, maximum chemical binding capacity, dissociation constant, and photo-isomerization rate. The HVSMIP was applied to detect trace chlorpyrifos in fruit and vegetable samples. This was achieved by measuring the trans→cis rate constant of the HVSMIP in the sample solution, with good recoveries, low relative standard deviations, and a low detection limit. Copyright © 2021 Elsevier Ltd. All rights reserved.
CitationChen, M.-J., Yang, H.-L., Si, Y.-M., Tang, Q., Chow, C.-F., & Gong, C.-B. (2021). A hollow visible-light-responsive surface molecularly imprinted polymer for the detection of chlorpyrifos in vegetables and fruits. Food Chemistry. Advance online publication. doi: 10.1016/j.foodchem.2021.129656
- Surface imprinting technique
- Molecularly imprinted polymer
- Visible-light-responsive material
- Pesticide residue
- Food safety