Multifunctional Textile-Based Photonic Crystal Colorimetric Sensors with Fast Water Response and Antimicrobial Function

In recent years, textile-based colorimetric sensors prepared based on photonic crystals (PCs) structural colors have received more and more attention. However, the development of textile-based colorimetric sensors with multifunctionality is still a challenge. In this study, multifunctional textile-based colorimetric sensors were developed by introducing an innovative PCs system that integrated water-responsive and antimicrobial properties. Novel poly(styryl-tert-butyl acrylate-[3-(methylacrylamide) propyl] trimethylammonium chloride) (PSTM) microspheres containing quaternary ammonium salt groups were synthesized. These microspheres were then utilized to create a textile-based PCs colorimetric sensor that exhibits antimicrobial activity. The particle sizes of the synthesized PSTM microspheres were effectively controlled (353.1, 301.1, 271.5, 263.2, and 242.6 nm) by regulating the monomer mass ratio. As the microsphere particle size decreased, the structural color generated after their atomization and deposition on the fabrics exhibited a blue shift, transitioning sequentially from brownish yellow and green to cyan, blue, and finally purple. These textile-based colorimetric sensors with different structural colors showed fast (less than 2 s) and reversible responses to water, and they also responded to different levels of water content and ethanol solution concentration. These textile-based colorimetric sensors had excellent response stability and could be reused more than 500 times. They also showed excellent antimicrobial properties against E. coli and S. aureus, with antimicrobial rates both greater than 99%. This integrated multifunctional textile-based colorimetric sensor with tunable structural color, rapid water sensing, and inherent antimicrobial function offers a promising strategy for applications such as water content monitoring in medical health, sports fitness, and infant care.