Zhang Can, Zhang Yan, Wang Shuo
Tianjin Key Laboratory of Food Nutrition and Safety, Faculty of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, People's Republic of China.
J Agric Food Chem. 2006 Apr 5;54(7):2502-7. doi: 10.1021/jf0531407.
Membrane-based competitive immunoassays using gold particles and horseradish peroxidase (HRP) as tracers in flow-through and lateral-flow formats for multianalysis of carbaryl and endosulfan were developed. For gold-based immunoassay, membrane strips were coated with goat anti-rabbit IgG (control line) and carbaryl hapten-ovalbumin (OVA) and endosulfan hapten-OVA (test lines). The visual detection limits for carbaryl and endosulfan were 100 and 10 microg/L in gold-based assays, respectively. For immunoassay using HRP as tracer, anti-carbaryl and anti-endosulfan antibodies were separately coated on the membrane as test lines, and the visual detection limits were 10 microg/L for carbaryl and 1 microg/L for endosulfan. The developed assays used gold particles and HRP as labels, respectively; 10 times enhancement in the visual detection limit using HRP label was obtained in the study. Matrix interference was eliminated by appropriate dilution of sample extracts with buffer. For the validation of the multianalyte assay, the samples were screened by multianalyte gold-based assay and confirmed by HPLC for carbaryl determination and by GC for endosulfan determination. The results of multianalyte gold-based flow-through assay for the determination of carbaryl and endosulfan were in good agreement with the results of instrumental analysis (HPLC with ultraviolet detection and GC with electron capture detection). The developed multianalyte immunoassays for which the results were interpreted visually can be used as convenient qualitative tools for on-site rapid screening of carbaryl and endosulfan simultaneously in agricultural products.
开发了基于膜的竞争性免疫测定法，该方法采用金颗粒和辣根过氧化物酶（HRP）作为示踪剂，以流通式和侧流式形式对西维因和硫丹进行多分析。对于基于金的免疫测定，将膜条用山羊抗兔IgG（控制线）以及西维因半抗原-卵清蛋白（OVA）和硫丹半抗原-OVA（测试线）包被。在基于金的测定中，西维因和硫丹的目视检测限分别为100和10 μg/L。对于使用HRP作为示踪剂的免疫测定，抗西维因和抗硫丹抗体分别作为测试线包被在膜上，西维因的目视检测限为10 μg/L，硫丹为1 μg/L。所开发的测定法分别使用金颗粒和HRP作为标记物；在该研究中，使用HRP标记物使目视检测限提高了10倍。通过用缓冲液适当稀释样品提取物消除了基质干扰。为了验证多分析物测定法，通过多分析物基于金的测定法对样品进行筛选，并通过HPLC测定西维因以及通过GC测定硫丹来进行确认。基于金的流通式多分析物测定法测定西维因和硫丹的结果与仪器分析结果（带紫外检测的HPLC和带电子捕获检测的GC）高度一致。所开发的结果可目视解读的多分析物免疫测定法可作为方便的定性工具，用于现场快速同时筛选农产品中的西维因和硫丹。
