A high performance laser induced graphene (LIG) dual biosensor for simultaneous monitoring of glucose and lactate

The growing demand for efficient and reliable biosensors has driven significant advancements in the development of innovative platforms for real-time monitoring of key biomarkers. In this work, we developed a novel dual biosensing platform designed for simultaneous detection of glucose and lactate, leveraging a laser scribing technology. Individual glucose and lactate biosensors were firstly fabricated, using three electrode designs and Laser Induced Graphene (LIG) as transduction electrode. The individual biosensors displayed high linear range in the relevant sweat physiological range, good sensitivity (41.1 and 12.4 μA mM -1 cm -2 for glucose and lactate, respectively), Limit of Detection (LOD, 14.9 μM and 2.4 mM for glucose and lactate) and superior short- and long-term stability. Following optimization and in-depth characterization of the individual platforms, a dual sensing platform was designed to offer robust and reliable simultaneous detection of glucose and lactate in a single, integrated system. The dual biosensor maintained the performance displayed in single format, exhibiting sensitivities of 41.2 μA cm -2 mM -1 and 12.0 μA cm -2 mM -1 for glucose and lactate, respectively. The dual platform was successfully tested in artificial sweat, demonstrating its potential for precise and reliable biomarker monitoring in continuous health monitoring systems and point-of-care diagnostic. • Developed a dual biosensor platform based on Laser Induced Graphene (LIG) electrodes using Direct Laser Writing (DLW) on flexible polyimide films. • Achieved high stability, efficiency, and reproducibility by a cost-effective visible hobby laser (450 nm) and optimizing instrumental settings. • Optimized and established biofunctionalization procedure for glucose and lactate biosensors. • The biosensors exhibited high sensitivity, high selectivity, operational stability (2 hours continuous use) and long-term storage stability (8 weeks for glucose, 4 weeks for lactate). • Successfully developed a dual-platform system for simultaneous glucose and lactate detection with performance matching individual sensors, demonstrating robustness for practical biomarker monitoring.