Development of Flexible Lactate-Specific Molecularly Imprinted Polymers Based on Laser-Induced Graphene Electrochemical Biosensors for Disease Diagnosis

Lactate is a critical biomarker linked to conditions such as sepsis, ischemia, cancer, and heart failure. Current lactate detection methods remain invasive, costly, and unsuitable for real-time, continuous monitoring. This study presents the development of a flexible, non-enzymatic electrochemical biosensor based on laser-induced graphene (LIG) electrodes modified with gold nanoparticles (AuNPs) and molecularly imprinted polymers (MIPs) for highly selective and sensitive lactate measurement. The integration of AuNPs enhanced surface conductivity and provided nanoscale heterogeneity, facilitating superior signal amplification. The optimized LIG/AuNP/MIP sensor achieved an extensive dynamic detection range from 0.1 μM to 1000 μM, with an outstanding detection limit of 0.033 μM and a strong linear correlation (R² = 0.9556). The biosensor exhibited excellent selectivity against common interferents such as glucose, uric acid, ascorbic acid, and potassium ions. Stability studies demonstrated robust performance after prolonged storage at 4 °C, with regeneration enabled via CTAB treatment. Validation using artificial saliva yielded recovery rates between 102% and 113%, confirming accuracy in complex biological matrices. Mechanical tests further confirmed exceptional flexibility, with ~98% signal retention after mechanical twisting, supporting its application in wearable technologies. Compared to conventional enzymatic and non-enzymatic platforms, the LIG/AuNP/MIP biosensor offers enhanced sensitivity, stability, and durability. These findings establish a strong foundation for the future development of integrated, non-invasive, continuous lactate monitoring devices suitable for athletic performance tracking, critical care diagnostics, and personalized health management.