Abstract:
Electrochemical biosensors require electrode materials that are scalable, affordable, and effective for detecting target analyte. Laser-induced graphene (LIG) has emerged as a promising electrode material, yet traditional fabrication methods using expensive CO2 lasers limit accessibility. In this work, we report a low-cost and scalable fabrication strategy for flexible LIG electrodes using direct laser writing with a 10W, 455 nm diode laser. While bare LIG offers excellent conductivity and porosity, it lacks specific binding sites for target molecules, resulting in limited sensitivity. Surface functionalization with metal–organic frameworks (MOFs) offers a pathway to overcome this limitation; however, most MOF–LIG hybrids have been applied to gas sensing, leaving liquid-phase analyte detection largely unexplored. To improve sensor’s performance, MIL-100 MOF was incorporated onto the LIG electrodes via a simple drop-casting process. As a proof-of-concept, Ciprofloxacin detection was demonstrated with a detection limit of 6.04 nM. These findings establish MOF functionalized LIG electrodes as a versatile, low-cost, and scalable platform for sensitive solution-phase electrochemical sensing in environmental and biomedical applications.