Feedback-Guided SERS-Photothermal Patch for Maintaining Redox Homeostasis in Diabetic Foot Ulcers

Excessive oxidative stress and chronic inflammation are key obstacles to diabetic foot ulcer (DFU) healing. However, indiscriminate scavenging of reactive oxygen species (ROS) can disrupt physiological redox signaling that supports tissue repair. Here, we present a flexible feedback-guided sensing-and-treating patch integrating a ratiometric surface-enhanced Raman scattering (SERS) probe for real-time H₂O₂ monitoring with a photothermal-triggered dimethylthiourea (DMTU) release system. The SERS probe enables quantitative detection of H₂O₂ through a phenylboronic acid reporter, while near-infrared (808 nm) irradiation precisely triggers on-demand antioxidant delivery to restore physiological H₂O₂ levels. In diabetic mouse models, this hybrid patch effectively reduced oxidative stress, modulated inflammatory cytokines, promoted angiogenesis and collagen deposition, and markedly accelerated wound closure without adverse systemic effects. This work establishes a monitoring-guided redox-regulation strategy for intelligent, responsive wound management and highlights the potential of SERS-based theranostic materials in advanced biomedical applications.