Methacrylated Chitosan Methacrylated Poly(vinyl alcohol)-Based Hydrogel Patch for Long-Term Electrochemical Wound pH Sensing

While every wound has the potential to become chronic, the risk is significantly higher in individuals with specific medical conditions. Given this inherent risk, continuous wound monitoring patches are beneficial for all wound types throughout the healing process, enabling the early detection and management of chronic wound development. In this work, we introduce an eco-friendly, hydrogel-integrated, capillary-driven wound patch designed for continuous pH monitoring. The hydrogel, synthesized from methacrylated chitosan and methacrylated poly(vinyl alcohol), provides antibacterial properties, tissue adhesion, and moisture retention, thereby supporting stable electrochemical pH detection. A paper-based, capillary-driven microfluidic layer facilitates fluid transport toward an evaporation pad, enhancing liquid uptake by approximately 4-fold after 2 h compared to the hydrogel alone. In vitro experiments demonstrated that the hydrogel-integrated sensor effectively monitored pH, exhibiting a near-linear voltage response of 16.92 mV per pH unit. The implementation of such a wound dressing represents a significant advancement in wound healing applications, combining functionality with environmental sustainability.