2026-09-07 九州大学
本研究の概要
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1565
- https://www.sciencedirect.com/science/article/pii/S0308814626030591
ダイズ中のダイジンおよびゲニスチンを迅速かつ簡便に検出するための、Split-GFPベースの均一オープンサンドイッチ免疫測定法 Split-GFP-based homogeneous open sandwich immunoassay for rapid and simple detection of daidzin and genistin in soybeans
Thi Huynh Anh Huynh, Munetaka Shiratsuchi, Poomraphie Nuntawong, Hiroyuki Tanaka, Satoshi Morimoto, Seiichi Sakamoto
Food Chemistry Available online 27 August 2026
DOI:https://doi.org/10.1016/j.foodchem.2026.150899
Highlights
- A homogeneous split-GFP-based open sandwich immunoassay was developed.
- VH and VL domains were fused separately to GFP1–10 and GFP11.
- Daidzin and genistin promoted VH–VL association and GFP complementation.
- The assay quantified combined daidzin and genistin-equivalent content in 2 h.
- The working range was 0.039–10.0 μg mL−1 with an LOD of 27.9 ng mL−1.
Abstract
This study reports the first split-GFP-based homogeneous open sandwich immunoassay for the convenient detection of major soy isoflavone glycosides, daidzin (DZ) and genistin (GEN). GFP1–10 and GFP11 were fused to the heavy-chain variable (VH) and light-chain variable (VL) domains of a DZ-recognizing monoclonal antibody with cross-reactivity toward GEN. The presence of DZ or GEN promoted VH–VL interaction, enabling GFP reconstitution and fluorescence activation without immobilization, blocking, or washing. The N-terminal GFP11 fusion variant exhibited superior performance. The immunoassay was completed within 2 h, with a working range of 0.039–10.0 μg mL−1, a limit of detection of 27.9 ng mL−1, intra- and inter-day coefficients of variation of ≤ 14.6% and ≤ 11.2%, respectively, spike recoveries of 95.8–111.7%, and a strong linear association with HPLC results (R2 = 0.970) in soy and soy-derived products. This homogeneous split-GFP immunoassay provides a simple approach for compositional assessment of combined DZ and GEN-equivalent content in food products.
