Continuous lactate monitoring is critical for early detection and management of sepsis, shock, and metabolic stress, yet current serum assays remain invasive, intermittent, and resource-intensive. We present a clinical evaluation of a minimally invasive microneedle-based electrochemical biosensor for real-time interstitial fluid (ISF) lactate monitoring. The microneedle biosensor features a platinum working electrode modified with a lactate oxidase reagent layer and a polyvinyl chloride anti-fouling membrane for H2O2-mediated amperometry, toward highly selective and stable ISF lactate detection. In a pilot study of twenty-one participants across an intensive care unit, emergency department, cardiopulmonary exercise testing, and controlled laboratory settings, two enzyme-based microneedle sensors placed on the forearm and thigh continuously tracked lactate for 4 h. Sensor performance demonstrated strong agreement with blood lactate assays (r = 0.94), high diagnostic accuracy for hyperlactatemia (>4 mmol/L; receiver operating characteristic analysis, area under the curve = 0.95), and minimal bias (-0.028 mmol/L) over a wide dynamic range (0.7-22.9 mmol/L) with high selectivity against interferents. No significant ISF-blood differences (p > 0.05) or adverse events were observed. These findings establish microneedle biosensors as a promising platform for precision medicine, with considerable potential to transform sepsis care, guide resuscitation, and improve assessment of exertional dyspnea.
Djassemi et al. (2026) studied this question.