title: Quantum dot-based immunochromatographic fluorescent biosensor for biomonitoring trichloropyridinol, a biomarker of exposure to chlorpyrifos.
abstract: 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.
authors.affiliation: Department of Chemistry and Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 China.
authors.forename: Zhexiang
authors.initials: Z
authors.lastname: Zou
authors.forename: Dan
authors.initials: D
authors.lastname: Du
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Jordan N
authors.initials: JN
authors.lastname: Smith
authors.forename: Charles
authors.initials: C
authors.lastname: Timchalk
authors.forename: Yaoqun
authors.initials: Y
authors.lastname: Li
authors.forename: Yuehe
authors.initials: Y
authors.lastname: Lin
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004390:Chlorpyrifos / Q000378:metabolism*; D004867:Equipment Design; D005453:Fluorescence; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D008297:Male; D010575:Pesticides / Q000378:metabolism*; D011728:Pyridones / Q000097:blood* / Q000276:immunology; D045663:Quantum Dots; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010575:Pesticides; D011728:Pyridones; C012587:3,5,6-trichloro-2-pyridinol; D004390:Chlorpyrifos