Redox responsive photonic crystals with broad wavelength shifts and their efficient detection of hydrogen peroxide and catalase

Photonic crystals with unique optical properties are commonly chosen as the foundation material in the fabri-cation of visual sensors. Analogously, ferrocene is also widely used in sensor manufacturing because of its mild redox conditions, high biocompatibility, and chemical stability. The present work successfully prepared poly-meric photonic crystals with ferrocene. By combining the redox reaction of hydrogen peroxide and ferrocene, the high-efficiency visual detection of hydrogen peroxide and catalase was realized. Hydrogen peroxide solution could be decomposed to produce oxygen under certain conditions, thus, oxidizing the reduced ferrocene. Vari-ations in the morphology, hydrophilicity, and hydrophobicity of ferrocene before and after redox will lead to volume shrinkage of the photonic crystal hydrogels, resulting in a significant blue shift of the sensors up to 253 nm. At the same time, the color of the sensors changes from red to purple with the shift of reflection. In general, the simple and rapid response sensors can achieve full-wavelength and full-color response in the visible wave-length range, which exhibited excellent performance in the detection of hydrogen peroxide and catalase.

Automated summary

Polymeric photonic crystals containing ferrocene were successfully prepared and used for efficient visual detection of hydrogen peroxide and catalase. The variations in the morphology of ferrocene before and after redox resulted in volume shrinkage of the sensors and a significant blue shift in reflection. The sensors exhibited excellent performance in detecting hydrogen peroxide and catalase.