Chen Junjie, Chen Lidan, Zhang Yongyi, Xiang Siyi, Zhang Ruizhou, Shen Yudong, Liao Jiaming, Xie Huahui, Yang Jinyi
Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
Wens Institute, Wens Foodstuff Groups Co., Ltd., Yunfu 527400, China.
Foods. 2024 Jan 28;13(3):423. doi: 10.3390/foods13030423.
Picoxystrobin (PIC) is a fungicide extensively used for disease control in both crops and vegetables. Residues of PIC in vegetables pose a potential threat to human health due to their accumulation in the food chain. In this study, a specific PIC monoclonal antibody (mAb) was developed by introducing a carboxylic acid arm into PIC and subsequently preparing a hapten and an artificial antigen. A sensitive and rapid time-resolved fluorescence immunochromatographic assay (TRFICA) was established based on the mAb. Subsequently, using a time-resolved fluorescent microsphere (TRFM) as signal probe, mAbs and microspheres were covalently coupled. The activated pH, the mAb diluents, the mAb amount, and the probe amount were optimized. Under optimized conditions, the quantitative limits of detection (qLOD) of PIC in cucumber, green pepper, and tomato using TRFICA were established at 0.61, 0.26, and 3.44 ng/mL, respectively; the 50% inhibiting concentrations (IC) were 11.76, 5.29, and 37.68 ng/mL, respectively. The linear ranges were 1.81-76.71, 0.80-35.04, and 8.32-170.55 ng/mL, respectively. The average recovery in cucumber, green pepper, and tomato samples ranged from 79.8% to 105.0%, and the corresponding coefficients of variation (CV) were below 14.2%. In addition, 15 vegetable samples were selected and compared with the results obtained using ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). The results revealed a high degree of concordance between the proposed method and UPLC-MS/MS. In conclusion, the devised TRFICA method is a valuable tool for rapid, on-site, and highly sensitive detection of PIC residues in vegetables.
吡唑醚菌酯（PIC）是一种广泛用于农作物和蔬菜病害防治的杀菌剂。由于其在食物链中的积累，蔬菜中的PIC残留对人类健康构成潜在威胁。在本研究中，通过在PIC中引入羧酸臂，随后制备半抗原和人工抗原，开发了一种特异性PIC单克隆抗体（mAb）。基于该mAb建立了一种灵敏、快速的时间分辨荧光免疫层析测定法（TRFICA）。随后，使用时间分辨荧光微球（TRFM）作为信号探针，将mAb与微球共价偶联。对活化pH、mAb稀释剂、mAb用量和探针用量进行了优化。在优化条件下，采用TRFICA测定黄瓜、青椒和番茄中PIC的定量限（qLOD）分别为0.61、0.26和3.44 ng/mL；50%抑制浓度（IC）分别为11.76、5.29和37.68 ng/mL。线性范围分别为1.81 - 76.71、0.80 - 35.04和8.32 - 170.55 ng/mL。黄瓜、青椒和番茄样品中的平均回收率为79.8%至105.0%，相应的变异系数（CV）低于14.2%。此外，选取了15个蔬菜样品，并与超高效液相色谱/串联质谱（UPLC-MS/MS）的检测结果进行比较。结果表明，所提出的方法与UPLC-MS/MS具有高度一致性。总之，所设计的TRFICA方法是一种用于快速、现场和高灵敏度检测蔬菜中PIC残留的有价值工具。
