Microfluidic Devices for Pesticide Monitoring: From Broad-Spectrum Enzyme Inhibition to Targeted Immunoassays

Microfluidic technologies provide powerful platforms for pesticide analysis, offering portability, low cost, and assay formats that can be tuned for either broad-spectrum screening or highly specific detection. Enzyme inhibition enables classification of pesticides by their chemical mode of action, while immunoassays provide analyte-specific recognition through selective antibody binding. This work highlights both approaches through two microfluidic devices. The first introduces a capillary-driven microfluidic device employing a tyrosinase-based enzymatic inhibition assay for dithiocarbamate detection. Using Ziram as a model analyte, the assay achieved a detection limit of 1.5 ppm, demonstrated strong resistance to environmental interferences, and retained 90% enzymatic activity after one week of storage. Analysis of pesticide-contaminated gloves yielded recovery rates of 68.9%–87.5%, highlighting their potential for monitoring occupational exposures. The second focuses on a competitive immunoassay for glyphosate. Initial ELISA studies confirmed competition between immobilized and free glyphosate, producing a clear colorimetric signal. Current efforts are ongoing to translate the assay to a microfluidic platform, where controlled flow geometries enable sequential reagent delivery, on-chip washing, and substrate activation, thereby minimizing background and enabling quantitative detection. Together, these results demonstrate complementary strategies for pesticide monitoring: enzyme inhibition for broad, class-level detection and immunoassays for highly targeted analysis. Such microfluidic systems represent a path toward practical, field-ready tools for environmental and occupational pesticide surveillance.