Direct analysis of trichloropyridinol in human saliva using an Au nanoparticles-based immunochromatographic test strip for biomonitoring of exposure to chlorpyrifos

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• 作者：Weiying Zhang ; Yong Tang ; Dan Du ; Jordan Smith ; Charles Timchalk ; Deli Liu ; Yuehe Lin
• 关键词：Trichloropyridinol ; Organophosphorus pesticides ; Immunochromatographic biosensor ; Biomarker ; Au nanoparticles
• 刊名：Talanta
• 出版年：2013
• 出版时间：30 September, 2013
• 年：2013
• 卷：114
• 期：Complete
• 页码：261-267
• 全文大小：2690 K

文摘

A portable immunochromatographic strip-based biosensor for direct detection of trichloropyridinol (TCP), a specific biomarker of exposure to chlorpyrifos, in human saliva sample is presented. In this approach, a series of immunoreactions was performed on the test strip, where the targeted analytes (TCP) bound to the Au nanoparticles-labeled antibodies on the conjugate pad to form analyte-Au-antibody conjugates, and then free Au-labeled antibodies were captured by TCP-BSA in the test zone. Captured Au nanoparticles, increased with decreased levels of analytes, can be observed visibly without any equipment and later quantified by a colorimetric reader. Several experimental parameters were optimized including Au nanoparticle-to-TCP antibody coupling ratio, the amount of Au-labeled TCP antibody, immunoreaction time, the pretreatment of sample pad and the preparation of stock solution of Au-TCP antibody that realize sensitivity, selectivity and direct detection of TCP. Under optimal conditions, this biosensor displays a highly linear range of 0.625-20 ng/mL TCP, with a detection limit of 0.47 ng/mL. Moreover, the immunosensor was successfully used for direct analysis of human saliva sample without any pretreatment. These results demonstrate that this Au nanoparticles-based immunochromatographic test strip (ITS) provides a simple, accurate, and quantitative tool for TCP detection and holds a great promise for point-of-care and in-field analysis of other biomarkers.