pH-responsive fluorescent carbon quantum dots-integrated sericin hydrogel for simultaneous wound microenvironment monitoring and antibacterial therapy

Silk sericin-derived pH-responsive CQDs were synthesized via microwave irradiation. • Composite hydrogel integrates photodynamic and contact-active antibacterial mechanisms. • pH-triggered fluorescence switching allows real-time visual wound monitoring. • PG greatly toughens the hydrogel through a dynamic energy dissipation network. Chronic wounds are frequently accompanied by bacterial infection and dynamic pH fluctuations, creating a demand for intelligent wound dressings capable of simultaneous infection management and wound-state monitoring. Herein, a multifunctional pH-responsive antibacterial hydrogel dressing was fabricated via free radical polymerization, by incorporating silk sericin-derived pH-responsive carbon quantum dots (pH-CQDs) into a propylene glycol (PG)-reinforced zwitterionic hydrogel network. pH-CQDs were efficiently synthesized from silk sericin, m -phenylenediamine, and polyethyleneimine using a microwave-assisted strategy, exhibiting highly sensitive and reversible pH-responsive fluorescence, along with potent antibacterial activity, achieving over 99% inhibition against S. aureus , E. coli , and P. aeruginosa . Benefiting from the introduction of PG, abundant hydrogen-bond interactions were established within the hydrogel matrix, forming an enhanced energy-dissipation network that significantly improved the mechanical robustness, toughness, and adhesion properties of the hydrogel. The resulting composite hydrogel exhibited remarkable pH-dependent fluorescence color changes, enabling visual monitoring of wound microenvironment variations. Additionally, the hydrogel possessed favorable water-retention capability, swelling behavior, fluorescence stability, disinfectant tolerance and low cytotoxicity. Due to the synergistic integration of pH-responsive sensing, robust mechanical performance, and long-lasting antibacterial activity, the obtained hydrogel represents a promising platform for intelligent wound management and infection monitoring. Download: Download high-res image (209KB) Download: Download full-size image