A Monoclonal Antibody‐based Lateral Flow Immunochromatographic Assay for Rapid Detection of Derrisisoflavone A in <i>Derris scandens</i> (Roxb.) Benth

Derrisisoflavone A is a prenylated isoflavonoid and a chemical marker in the stem of Derris scandens (Roxb.) Benth., it is a suitable chemical marker for this plant. Conventional analytical techniques, such as high-performance liquid chromatography, liquid chromatography-mass spectrometry, and immunoassays, offer high sensitivity but rely on complex analytical equipment and specialized expertise, thereby limiting their applicability for rapid on-site analysis. In this study, a lateral flow immunochromatographic assay (LFIA) employing gold nanoparticle (AuNP)-labeled monoclonal antibodies (mAbs) was developed for qualitative detection of derrisisoflavone A in D. scandens plant materials and herbal products. The LFIA was designed in a competitive format using AuNPs-mAbs conjugates as the detection probe, derrisisoflavone A-cationized ovalbumin conjugates applied on the test zone, and anti-mouse immunoglobulin G antibody on the control zone. Under optimized conditions, the assay was evaluated for sensitivity and specificity and validated by comparison with a well-established indirect competitive enzyme-linked immunosorbent assay (icELISA) using various D. scandens plant parts, commercial products, and representative Fabaceae species. The LFIA exhibited a visual limit of detection of 100 µg/mL, defined by complete inhibition of the test zone signal, and demonstrated high analytical specificity with undetectable cross-reactivity toward structurally related isoflavonoids or prenylated flavonoids. The analytical results showed good agreement with those obtained by icELISA. Although less sensitive than quantitative methods, the developed LFIA provides a rapid, simple, and reliable screening tool for on-site quality control and preliminary assessment of derrisisoflavone A in D. scandens and related products.