Bioresorbable electrochemical sensors for continuous deep-tissue lactate monitoring in critical care.

Lactate is a key metabolite and prognostic biomarker, reflecting oxygen delivery, cellular demand, and mitochondrial function. Current clinical lactate monitoring, however, relies on intermittent blood sampling, limiting localized interrogation, dynamic tracking and early intervention in critical care. Here, we report a bioresorbable and flexible electrochemical sensor for continuous deep-tissue lactate monitoring. By leveraging a previously unreported enzyme-assisted proton-intercalation mechanism, we establish a unique electrochemical sensing interface that enables high-performance lactate detection entirely with biodegradable materials. Integrated with a wireless module, the device enables in vivo real-time recording with excellent sensitivity and stable operation over clinically relevant timescales (> 10 days), without requiring secondary surgeries for device retrieval. The sensor robustly captures organ-specific lactate dynamics during hypoxia and epileptic seizures. Notably, we identify that increases in pericardial lactate precede systemic changes detected by conventional monitoring in septic shock, providing a prominent marker for early warning and timely intervention. Pericardial lactate-guided treatment markedly improves hemodynamic stability and prevents septic shock within the monitoring window. This work enables paradigm-shifting strategies for bioresorbable, implantable sensors that monitor vital metabolites in real time, supporting early diagnosis, guided intervention and improved outcomes in intensive care.