College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, P. R. China.
Anal Methods. 2024 Mar 7;16(10):1546-1553. doi: 10.1039/d4ay00026a.
The compound 3-phenoxybenzoic acid (3-PBA) is frequently utilized as a biomarker to detect exposure to various pyrethroids. In this study, a bivalent nanobody (Nb2) specifically targeting 3-PBA was biotinylated and immobilized onto streptavidin (SA)-modified bacterial magnetic nanoparticles (BMPs), resulting in the formation of BMP-SA-Biotin-Nb2 complexes. These complexes demonstrated remarkable stability when exposed to strongly acidic solutions (4 M HCl), methanol (80%), and high ionic strength (1.37 M NaCl). An immunoassay was subsequently developed utilizing BMP-SA-Biotin-Nb2 as the capture agent and 3-PBA-horseradish peroxidase as the detection probe. The immunoassay exhibited an IC value (half-maximum signal inhibition concentration) of 1.11 ng mL for 3-PBA. To evaluate the accuracy of the assay, spiked sheep and cow urine samples (ranging from 3.0 to 240 ng mL) were analyzed. The quantitative recoveries ranged from 82.5% to 113.1%, which agreed well with the findings obtained using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Overall, the BMP-SA-Biotin-Nb2-based immunoassay holds great promise for rapid monitoring of 3-PBA following acid dissociation.
3-苯氧基苯甲酸（3-PBA）常被用作检测各种拟除虫菊酯暴露的生物标志物。在这项研究中，一种双价纳米抗体（Nb2）被生物素化并固定在链霉亲和素（SA）修饰的细菌磁纳米颗粒（BMP）上，形成 BMP-SA-生物素-Nb2 复合物。这些复合物在暴露于强酸性溶液（4 M HCl）、甲醇（80%）和高离子强度（1.37 M NaCl）时表现出显著的稳定性。随后，利用 BMP-SA-生物素-Nb2 作为捕获剂和 3-PBA-辣根过氧化物酶作为检测探针，开发了一种免疫测定法。该免疫测定法对 3-PBA 的 IC 值（半最大信号抑制浓度）为 1.11ng mL。为了评估该测定法的准确性，分析了添加了 3-PBA 的绵羊和牛尿液样品（浓度范围为 3.0 至 240 ng mL）。定量回收率在 82.5%至 113.1%之间，与液相色谱-串联质谱（LC-MS/MS）的结果一致。总的来说，基于 BMP-SA-生物素-Nb2 的免疫测定法在酸解后快速监测 3-PBA 方面具有很大的应用前景。
