title: Direct analysis of trichloropyridinol in human saliva using an Au nanoparticles-based immunochromatographic test strip for biomonitoring of exposure to chlorpyrifos.
abstract: 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.
authors: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan 430079, PR China.
authors: Weiying
authors: W
authors: Zhang
authors: Yong
authors: Y
authors: Tang
authors: Dan
authors: D
authors: Du
authors: Jordan
authors: J
authors: Smith
authors: Charles
authors: C
authors: Timchalk
authors: Deli
authors: D
authors: Liu
authors: Yuehe
authors: Y
authors: Lin
mesh_terms: D000941:Antigens / Q000737:chemistry / Q000276:immunology; D004390:Chlorpyrifos; D002846:Chromatography, Affinity / Q000295:instrumentation* / Q000379:methods; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004785:Environmental Pollutants; D006046:Gold / Q000737:chemistry*; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry / Q000276:immunology; D007306:Insecticides; D053768:Metal Nanoparticles / Q000737:chemistry*; D011728:Pyridones / Q000032:analysis* / Q000737:chemistry; D012463:Saliva / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000276:immunology
chemical_list: D000941:Antigens; D004785:Environmental Pollutants; D018796:Immunoconjugates; D007306:Insecticides; D011728:Pyridones; D012710:Serum Albumin, Bovine; C012587:3,5,6-trichloro-2-pyridinol; D006046:Gold; D004390:Chlorpyrifos
keywords: Au nanoparticles; Biomarker; Immunochromatographic biosensor; Organophosphorus pesticides; Trichloropyridinol