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 fabrication 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 polymeric 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. Variations 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 wavelength range, which exhibited excellent performance in the detection of hydrogen peroxide and catalase. • A redox responsive photonic crystals with advantages of simple preparation, rapid response, good selectivity and strong anti-interference ability were developed. • The maximum reflection shift was up to 253 nm, achieving full-wavelength and full-color response. • The sensors can be potentially used for the detection of catalase in human serum.