A Laser‐Induced Graphene Biosensor With an Engineered Antifouling Interface for On‐Site Detection of Organophosphorus Pesticides

Organophosphorus pesticides (OPs) are extensively used in agriculture but pose significant health risks because of their potential residues in food products. However, conventional analytical methods often require centralized instrumentation, trained personnel, and time‐consuming sample processing, limiting their suitability for portable, affordable, and on‐site detection. Here, we report a laser‐induced graphene (LIG)‐based electrochemical biosensor incorporating a cobalt phthalocyanine (CoPc)‐modified antifouling interface for the on‐site detection of OPs. The LIG electrode offers high electrical conductivity, a large electroactive surface area, and an integrated quasi‐reference electrode, enabling efficient monitoring of the Co 2 + /Co + redox cycle for quantitative OP detection. The engineered antifouling nanocomposite suppresses nonspecific adsorption while maintaining efficient electron transfer, allowing reliable detection of chlorpyrifos (CPF) over a linear range of 10–1600 ppb with a limit of detection of 3.7 ppb. Coupled with a portable potentiostat, the sensor provides a low‐cost, field‐deployable platform capable of robust operation in complex food matrices. This work offers a practical approach for on‐site food safety monitoring and underscores the potential of LIG‐based electrochemical sensors for real‐world agricultural and environmental applications.