Development of flexible regenerable lactate-specific molecularly imprinted polymers based on laser-induced graphene electrochemical biosensor

Abstract

Lactate is a key biomarker for assessing tissue hypoxia, sepsis, and metabolic disorders, making its accurate detection essential for clinical diagnostics, health monitoring, and sports performance evaluation. Here we present a molecularly imprinted polymer (MIP)-based electrochemical sensor using a laser-induced graphene (LIG) electrode modified with poly(3,4-ethylenedioxythiophene) (PEDOT) for selective and sensitive lactate detection. Sensor fabrication was optimized, including PEDOT deposition and MIP synthesis conditions, to enhance imprinting efficiency and lactate recognition. Characterization using scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed uniform deposition and effective surface modification. Incorporating cetyltrimethylammonium bromide to regenerate the sensor surface improved signal stability and minimized non-specific binding. The flexible sensor maintained stable performance under mechanical stress and exhibited good operational stability. Using square wave voltammetry, the LIG-MIP biosensor demonstrated a wide detection range of 0.1–1000 μM with a high sensitivity of 27.68 μA/log μM, and a low detection limit of 0.033 μM. Selectivity toward lactate was confirmed in the presence of potent interferents in lactate analysis. The stability and reproducibility were evaluated and validated in artificial saliva. This flexible, highly sensitive regenerable MIP-based sensor offers a promising platform for real-time lactate monitoring in biomedical and wearable applications.