Construction and Optimization of a Novel Acetylcholine Ion-Selective Electrode and its Application for Trace Level Determination of Propoxur Pesticide
Abstract
This research presents the construction and optimization of an acetylcholine, ACh, ion-selective electrode, ACh-ISE, aiming to use it for the quantification of the propoxur pesticide. This analytical quantification is based on the evaluation of the acetylcholinesterase enzyme inhibition percentage, %EI, provoked by the pesticide, as a function of propoxur concentration; where the %EI is followed by means of the potentiometric determination of acetylcholine that does not react with the enzyme, using the constructed ACh-ISE. It was found that the ACh-ISE depicted a sub-Nernstian slope of (42.7 ± 2.8) mV decade-1, a ACh detection limit of 1.2 × 10-5 mol l-1, and the selectivity constants, Kpot, of 0.03 and 0.24 for Na+ and Choline+ cations, respectively. K+ and Ca2+ did not interfere. This new method designed to determine propoxur attained an outstanding detection limit of (2.89 ± 0.97) × 10-17 mol l-1 and a linear interval of (5.5 × 10-15-1.0 × 10-4) mol l-1.
- Publication:
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Journal of the Electrochemical Society
- Pub Date:
- January 2020
- DOI:
- 10.1149/1945-7111/ab8874
- Bibcode:
- 2020JElS..167h7501J
- Keywords:
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- Sensors;
- Electroanalytical Electrochemistry;
- Interface modification