High-affinity recombinant full-length antibody-based immunochromatographic strip assay for rapid and reliable detection of pyraclostrobin residues in food samples
Ying Liu, Shasha Jiao, Yunyun Chang, Xinying Lu, Pengyan Liu, Ying Zhao, Changchun Zha, Lirong Shen, Yirong Guo, Guonian Zhu
Abstract
In this study, a rapid and reliable gold nanoparticles immunochromatographic strip (GNPs-ICS) assay based on a full-length recombinant antibody (rAb) was established for pyraclostrobin detection in food samples. First, a hybridoma PY-C7 secreting pyraclostrobin-specific monoclonal antibody (mAb) was produced. The variable region sequences of PY-C7-mAb were obtained by PCR and Sanger sequencing and used for the rAb expression in HEK293(F) cells. By GNPs-ICS assay, the visual LOD of pyraclostrobin standards was 0.1 mg L−1 (rAb) and 0.2 mg L−1 (mAb). Validated by recovery test, the visual LOQ of pyraclostrobin could meet the MRLs of Chinese food safety standard in strawberry, banana and Chinese cabbage samples by GNPs-mAb/rAb-ICS, in which the rAb showed better sensitivity and stability. Moreover, the GNPs-rAb-ICS showed comparable reliability with LC-MS/MS for actual sample detection. Above all, GNPs-ICS assay based on the full-length rAb was qualified for rapid detection of pyraclostrobin in food samples.