Direct analysis of trichloropyridinol in human saliva using an Au nanoparticles-based immunochromatographic test strip for biomonitoring of exposure to chlorpyrifos.
Zhang W; Tang Y; Du D; Smith J; Timchalk C; Liu D; Lin Y
Talanta 2013 Sep; 114:261-267
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.
Nanotechnology; Organo-phosphorus-pesticides; Organo-phosphorus-compounds; Pesticides; Immunochemistry; Immunological-tests; Biological-monitoring; Biomarkers; Chromatographic-analysis; Antigens; Detectors; Exposure-assessment; Antibody-response; Colorimetry; Reaction-rates; Sample-preparation; Analytical-instruments; Analytical-processes; Metal-compounds; Biochemical-tests; Metabolites; Performance-capability; Equipment-reliability; Testing-equipment;
Author Keywords: Trichloropyridinol; Organophosphorus pesticides; Immunochromatographic biosensor; Biomarker; Au nanoparticles
Dan Du, Pacific Northwest National Laboratory, Richland, WA 99352, USA
7440-57-5; 2921-88-2; 6515-38-4
Agriculture, Forestry and Fishing
Battelle Pacific Northwest Laboratories