This review covers the progress in recent years on pH-responsive polymers integrated with natural colorants. The classification of various natural colorants, including anthocyanin, curcumin, and alizarin, and the pigments’ structural changes at different pH are introduced. Subsequently, the latest research in substrates for immobilizing natural colorants is discussed. Moreover, their applications on wound dressing for bacterial infections monitoring, smart package for food quality monitoring, and textile dyeing, are outlined. Finally, this study was summarized by emphasizing the current challenges and future opportunities in the field of pH-responsive polymers.
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