2,4‐Dichlorophenol molecularly imprinted two‐dimensional photonic crystal hydrogels

Abstract

Abstract A novel molecularly imprinted two‐dimensional (2‐D) photonic crystal hydrogels (MIPH) for sensitive and label‐free recognition of 2,4‐dichlorophenol (2,4‐DCP) was prepared. The 2‐D photonic crystal template was fabricated by using air‐water interface self‐assembly method. And then the template was embedded with molecularly imprinted polymer, which was synthesized with 2,4‐DCP as imprinted molecules, dimethyl sulfoxide as solvent, acrylic acid and acrylamide as functional monomers, N,N‐methylene bis acrylamide as cross‐linker, azobisisobutyronitrile as initiator. The imprinted molecules were removed by 0.01 M ammonia solution. The results indicated that the 2,4‐DCP molecularly imprinted 2‐D photonic crystal hydrogels has good response and recognition ability to 2,4‐DCP. When the molar ratio of cross‐linking density of MIPH is 2.3% and the molar ratio of imprinting molecule is 5.0%, the change of Debye ring diameter is the largest. The diameter of Debye ring increased by 7.1 mm when the concentration of 2,4‐DCP changed from 0 to 1 × 10 −6 M, and the particle spacing of MIPH reduced 38 nm. In addition, the diameter of the Debye ring hardly changed in the solution of analogues of 2,4‐DCP such as, phenol, 2‐chlorophenol, 2,4,6‐trichlorophenol and so on, indicating that the MIPH has highly sensitivity and specificity.