title: An approach to an inhibition electronic tongue to detect on-line organophosphorus insecticides using a computer controlled multi-commuted flow system.
abstract: An approach to an inhibition bioelectronic tongue is presented. The work is focused on development of an automated flow system to carry out experimental assays, a custom potentiostat to measure the response from an enzymatic biosensor, and an inhibition protocol which allows on-line detections. A Multi-commuted Flow Analysis system (MCFA) was selected and developed to carry out assays with an improved inhibition method to detect the insecticides chlorpyrifos oxon (CPO), chlorfenvinfos (CFV) and azinphos methyl-oxon (AZMO). The system manifold comprised a peristaltic pump, a set of seven electronic valves controlled by a personal computer electronic interface and software based on LabView® to control the sample dilutions into the cell. The inhibition method consists in the injection of the insecticide when the enzyme activity has reached the plateau of the current; with this method the incubation time is avoided. A potentiostat was developed to measure the response from the enzymatic biosensor. Low limits of detection of 10 nM for CPO, CFV, and AZMO were achieved.
authors.affiliation: Centro de Investigación y de Estudios Avanzados del Intituto Politecnico Nacional, Mexico. galonso@cinvestav.mx
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Alonso
authors.forename: Rocio B
authors.initials: RB
authors.lastname: Dominguez
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Marty
authors.forename: Roberto
authors.initials: R
authors.lastname: Muñoz
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry*; D000818:Animals; D001387:Azinphosmethyl / Q000031:analogs & derivatives / Q000032:analysis; D001557:Benzenesulfonates / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation*; D004390:Chlorpyrifos / Q000031:analogs & derivatives / Q000032:analysis; D004330:Drosophila / Q000737:chemistry*; D004791:Enzyme Inhibitors; D007306:Insecticides / Q000032:analysis*; D011199:Potentiometry / Q000379:methods; D012984:Software
chemical_list: D001557:Benzenesulfonates; D004791:Enzyme Inhibitors; D007306:Insecticides; D001387:Azinphosmethyl; C009618:O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphate; C034434:azinphosmethyl oxon; D000110:Acetylcholinesterase; D004390:Chlorpyrifos; C005285:ovex