Sequential Injection/Electrochemical Immunoassay for Quantifying the Pesticide Metabolite 3, 5, 6-Trichloro-2-Pyridinol

Journal Article · Sun Dec 04 04:00:00 EST 2005 · Electrochemistry Communications

DOI:https://doi.org/10.1016/j.elecom.2005.10.005· OSTI ID:876976

Liu, Guodong; Riechers, Shawn L; Timchalk, Chuck; Lin, Yuehe

An automated and sensitive sequential injection electrochemical immunoassay was developed to monitor a potential insecticide biomarker, 3, 5, 6-trichloro-2-pyridinol. The current method involved a sequential injection analysis (SIA) system equipped with a thin-layer electrochemical flow cell and permanent magnet, which was used to fix 3,5,6-trichloro-2-pyridinol (TCP) antibody coated magnetic beads (TCP-Ab-MBs) in the reaction zone. After competitive immunoreactions among TCP-Ab-MBs, TCP analyte, and horseradish peroxidase (HRP) labeled TCP, a 3, 3?, 5, 5?-tetramethylbenzidine dihydrochloride and hydrogen peroxide (TMB-H2O2) substrate solution was injected to produce an electroactive enzymatic product. The activity of HRP tracers was monitored by a square wave voltammetric scanning electroactive enzymatic product in the thin-layer flow cell. The voltammetric characteristics of the substrate and the enzymatic product were investigated under batch conditions, and the parameters of the immunoassay were optimized in the SIA system. Under the optimal conditions, the system was used to measure as low as 6 ng L-1 (ppt) TCP, which is around 50-fold lower than the value indicated by the manufacturer of the TCP RaPID Assay? kit (0.25 ug/L, colorimetric detection). The performance of the developed immunoassay system was successfully evaluated on tap water and river water samples spiked with TCP. This technique could be readily used for detecting other environmental contaminants by developing specific antibodies against contaminants and is expected to open new opportunities for environmental and biological monitoring.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 876976
• Report Number(s): PNNL-SA-46972; 12490; 6899
• Journal Information: Electrochemistry Communications, Journal Name: Electrochemistry Communications Journal Issue: 12 Vol. 7; ISSN 1388-2481
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
ANTIBODIES
Biomarkers
DETECTION
Environmental Molecular Sciences Laboratory
HYDROGEN PEROXIDE
IMMUNOASSAY
INSECTICIDES
Immunoassay
MANUFACTURERS
METABOLITES
MONITORING
MONITORS
PERMANENT MAGNETS
PEROXIDASES
PESTICIDES
SUBSTRATES
WATER
biosensor