title: Cholinesterase sensors based on screen-printed electrodes for detection of organophosphorus and carbamic pesticides.
abstract: Cholinesterase sensors based on screen-printed electrodes modified with polyaniline, 7,7',8,8'-tetracyanoquinodimethane (TCNQ), and Prussian blue have been developed and tested for detection of anticholinesterase pesticides in aqueous solution and in spiked grape juice. The influence of enzyme source and detection mode on biosensor performance was explored. It was shown that modification of the electrodes results in significant improvement of their analytical characteristics for pesticide determination. Thus, the slopes of the calibration curves obtained with modified electrodes were increased twofold and the detection limits of the pesticides were reduced by factors of 1.6 to 1.8 in comparison with the use of unmodified transducers. The biosensors developed make it possible to detect down to 2 x 10(-8) mol L(-1) chloropyrifos-methyl, 5 x 10(-8) mol L(-1) coumaphos, and 8 x 10(-9) mol L(-1) carbofuran in aqueous solution and grape juice. The optimal conditions for grape juice pretreatment were determined to diminish interference from the sample matrix.
authors.affiliation: Chemistry Department, Kazan State University, 18 Kremlevskaya Street, 420008, Kazan, Russia.
authors.forename: Alexey
authors.initials: A
authors.lastname: Ivanov
authors.forename: Gennady
authors.initials: G
authors.lastname: Evtugyn
authors.forename: Herman
authors.initials: H
authors.lastname: Budnikov
authors.forename: Francesco
authors.initials: F
authors.lastname: Ricci
authors.forename: Danila
authors.initials: D
authors.lastname: Moscone
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Palleschi
mesh_terms: D001628:Beverages / Q000032:analysis; D015374:Biosensing Techniques; D002235:Carbofuran / Q000032:analysis; D004390:Chlorpyrifos / Q000032:analysis; D002802:Cholinesterases / Q000032:analysis*; D003372:Coumaphos / Q000032:analysis; D004563:Electrochemistry; D004566:Electrodes; D007306:Insecticides / Q000032:analysis / Q000737:chemistry*; D027843:Vitis
chemical_list: D007306:Insecticides; D002802:Cholinesterases; D004390:Chlorpyrifos; D003372:Coumaphos; D002235:Carbofuran