title: Performance of a portable biosensor for the analysis of ethion residues.
abstract: Sensitive disposable potentiometric sensors for determination of the organophosphorus pesticide (OPs), ethion and its degradation residues have been constructed. The fabricated screen printed sensors are based on multi-walled carbon nanotube-polyvinyl chloride (MWNT-PVC) composite incorporated with α-cyclodextrin (α-CD) ionophore for butyrylcholine (BuCh) determination. Butyrylcholinesterase (BuChE) activity was measured through monitoring the BuCh hydrolysis using the fabricated sensors. The electrode potential changes linearly with BuChE concentration over the range from 0.04 to 0.4 U in phosphate buffer solution. This approach can also be used to analyze ethion and its degradation products in the concentration range from 0 to 330 ng mL(-1) by measuring the relative inhibition percentage of BuChE. From different ethion degradation products, inhibition by dioxon and monooxon were more potent than the parent pesticide. The proposed method was applied for determination of ethion in different samples with good accuracy and precision. The relative simple fabrication protocol of biosensor, high sensitivity and stability represents a promising approach for determination of environmental pollutants in field conditions.
authors.affiliation: Microanalysis Laboratory, National Research Centre, Dokki, Giza 12622, Egypt. Electronic address: elmorsykhaled@yahoo.com.
authors.forename: Elmorsy
authors.initials: E
authors.lastname: Khaled
authors.affiliation: Microanalysis Laboratory, National Research Centre, Dokki, Giza 12622, Egypt.
authors.forename: Manal S
authors.initials: MS
authors.lastname: Kamel
authors.affiliation: Microanalysis Laboratory, National Research Centre, Dokki, Giza 12622, Egypt.
authors.forename: H N A
authors.initials: HN
authors.lastname: Hassan
authors.affiliation: Applied Organic Chemistry Department, National Research Centre, Dokki, Giza 12622, Egypt.
authors.forename: Hassan
authors.initials: H
authors.lastname: Abdel-Gawad
authors.affiliation: Pharmaceutical and Medicinal Chemistry Department, National Research Centre, Dokki, Giza 12622, Egypt.
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Aboul-Enein
mesh_terms: D015374:Biosensing Techniques; D009946:Organothiophosphorus Compounds / Q000032:analysis*
chemical_list: D009946:Organothiophosphorus Compounds; C100038:ethion
keywords: Butyrylcholinesterase; Carbon nanotubes; Ethion degradation; Field measurement; Screen-printed potentiometric sensor