Development of nanogold immunochromatographic assay strip based on novel nanobody for rapid detection of imazalil in food and environmental water samples

作者：Yongyi Zhang, Haitao Zhang, Si-Yang Liu, Daoping Zeng, Tong Wang, Jie Yang, Keyin Guo, Zong Dai, Yuanxin Tian, Yudong Shen · 发表于：Biomedical Analysis · 年份：2026 · DOI：10.1016/j.bioana.2026.03.002 · 研究领域：Monoclonal and Polyclonal Antibodies Research、Biosensors and Analytical Detection、Advanced biosensing and bioanalysis techniques

The misuse of the broad-spectrum fungicide imazalil (IMZ) poses significant challenges to food safety and environmental safety, which requires rapid and accurate methods for detecting IMZ in complex food matrix and environmental samples. Herein, a novel anti-IMZ nanobodies (Nbs) with excellent stability and high expression yield was from a high-efficiency capacity of over 10 14 pfu/mL alpaca phage display nanobody library. Furthermore, the molecular recognition mechanism of anti-IMZ Nbs was simulated, and it was found that the causes affecting antibody sensitivity were mainly attributed to the hydrophobicity scales of active binding pocket, with synergistic enhancement of hydrogen bonding forces, and then proposed a directed evolution strategy for optimizing the anti-hydrophobic small molecule antibodies. Subsequently, a nanobody-based nanogold immunochromatography assay (Nb-GICA) was developed for IMZ detection in fruits and environmental water samples. The Nb-GICA achieved rapid detection (8 min per test), with a broad linear range (8.87–380.57 ng/mL) and a limit of detection (LOD) of 6.05–16.56 ng/mL. Additionally, the average spiked recovery rates in samples ranged from 82.6% to 117.5%, showing good consistency with GC-MS/MS results. The results demonstrated that the developed nanobody was a promising recognition element for the development of immunological methods to monitor IMZ residues in food and environmental samples. Schematic illustration of the preparation, recogn...