Development of a portable paper-based biosensor for the identification of genetically modified corn (Zea mays) and soybean (Glycine max)

: Genetically modified (GM) crops like corn and soy offer enhanced resistance traits but require consistent monitoring to manage gene flow, prevent resistant pests/weeds, and ensure regulatory compliance. In this study, we present a novel loop-mediated isothermal amplification (LAMP)-based microfluidic paper-based analytical device (μPAD) biosensor for the rapid and cost-effective detection of hybrid corn (RHS1) and soy (RR1 and RR2) traits directly from crude leaf extracts. Our μPAD-LAMP assay offers a promising solution for GM detection, characterized by its speed (within 60 minutes), simplicity (straightforward design), and affordability ($2.9 per test). We developed μPAD-LAMP cartridges and utilized an image analysis algorithm for time-resolved quantification of colorimetric changes, improving objectivity and accuracy. Our platform detected GM traits at 65 °C using a 1:7 dilution of leaf extracts in 0.12-0.25% SDS in water, without needing DNA purification. The limit of detection (LoD) for RHS1, RR1, and RR2 targets was 1.40×10 3 , 1.10×10 3 , and 1.00×10 3 genomic copies per reaction, respectively, with our μPAD-LAMP system. This portable μPAD-LAMP platform achieves 100% specificity, sensitivity, and accuracy in detecting GM corn and soy from leaf extracts, demonstrating its potential as a reliable on-site detection tool. Its adaptability to other GM crops or gene targets positions it as a promising standard for point-of-need (PON) assays in the GM industry.