Healing cascades and infections in wounds monitored using a wearable sensor of gaseous flux.

Capabilities for quantitative monitoring of chronic wounds remain an unmet clinical need, as existing diagnostic approaches rely on semiquantitative evaluation of symptoms that lack sensitivity especially during early stages of infection. Here, we present a scheme for tracking wound physiology that leverages a miniature, wireless skin-interfaced device for noncontact, transient measurements of the flux of volatile organic compounds (VOCs) and water vapor from the wound microenvironment. Unlike emerging smart bandage platforms that rely on physical contact with the fragile wound bed to interrogate liquid-phase biomarkers, this strategy uses an engineered microclimate and suspended suite of sensors to measure the diffusive transport of wound-derived gases across the wound surface but separated from it. The result enables quantitative evaluation of metabolic activity and healing progression without perturbing the healing tissues. In biofilm growth models of Staphylococcus aureus, measurements demonstrate that trends in VOC flux correlate strongly with bacterial growth kinetics and precede any visible biofilm formation. Longitudinal monitoring of infected and noninfected wounds on diabetic mice shows that concurrent measurements of water vapor and VOC flux provide complementary physiological insights, capturing both the trajectory of barrier restoration and the dynamics of bacterial burden. The findings establish this noncontact sensing scheme as a distinct and clinically translatable paradigm for wound monitoring, with broad implications for noninvasive surveillance of disease states in which tissue metabolic activity and skin barrier integrity serve as actionable physiological readouts.