Fabrication of multi-responsive photonic crystals based on selenium-containing copolymers

Responsive photonic crystals (PCs) have attracted great interest due to their adjustable structure color. In this study, a visual responsive PC responding to oxidation, light and pH stimuli was created based on a selenium-containing copolymer by the inverse opal photonic crystal (IOPC) method. Due to the weak bond energy of alkyl carbon–selenium bonds, they easily fracture under the influence of ROS, ultraviolet light and pH. This resulted in a significant drop in the refractive index (RI) of the medium and an increase in lattice spacing, which led to a blueshift of the band gap of RPCs based on Bragg's law . Meanwhile, the color of PCs varied significantly with the blueshift of the band gap, and a visual response to reactive oxygen species, ultraviolet radiation and pH was realized. This is a simple and direct method to detect oxidation and pH in the environment, as well as reveal the irradiation history of materials, which shows great promise in environmental monitoring.