Quantum dot-based immunochromatographic fluorescent biosensor for biomonitoring trichloropyridinol, a biomarker of exposure to chlorpyrifos.
Zou-Z; Du-D; Wang-J; Smith-JN; Timchalk-C; Li-Y; Lin-Y
Anal Chem 2010 Jun; 82(12):5125-5133
A novel and portable fluorescent sensor that integrates an immunochromatographic test strip assay (ITSA) with a quantum dot (QD) label and a test strip reader was described in this study for simple, rapid, and sensitive biomonitoring of an organophosphorus pesticide metabolite. The principle of this sensor is based on a competitive immunoreaction that was performed on an immunochromatographic test strip, where analytes compete with competitors (QD-conjugated analogs) to bind to antibodies on a test zone. Captured QDs serve as signal vehicles for fluorescent readout. In this work, 3,5,6-trichloropyridinol (TCP) is used as a model analyte to demonstrate the performance of the immunosensor. QD-TCP conjugates were synthesized and characterized with X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. Some parameters (e.g., the amount of QD-modified TCP and immunoreaction time) that govern sensitivity and reproducibility of ITSA were optimized. Under optimal conditions, the sensor has a wide dynamic range and is capable of detecting a minimum 1.0 ng/mL TCP standard analyte in 15 min. The sensor has been successfully applied for detection of TCP spiked in rat plasma with average recovery of 102.0%. Results demonstrate that this sensor provides a rapid, clinically accurate, and quantitative tool for TCP detection and shows great promise for in-field and point-of-care (POC) quantitative testing and screening for metabolite biomarkers, e.g., TCP, for humans exposed to pesticides.
Immunochemistry; Chromatographic-analysis; Bioassays; Biological-monitoring; Organo-phosphorus-pesticides; Metabolites; Pesticides; Testing-equipment; Immunological-tests; Detectors; Biomarkers; Fluorescence-spectrometry; Immune-reaction; Insecticides
Jun Wang, Pacific Northwest National Laboratory, Richland, WA 99352
Battelle Pacific Northwest Laboratories