title: Dual fluorescence and electrochemical detection of the organophosphorus pesticides--ethion, malathion and fenthion.
abstract: Organophosphorus (OP) based pesticides are known powerful inhibitors of cholinesterases, thus the toxicity of this class of compounds causes serious environmental and human health concerns. We report that benzodipyrido[3,2-a:2',3'-c]phenazine (BDPPZ) and 3,6-dimethylbenzodipyrido-[3,2-a:2',3'-c]phenazine (DM-BDPPZ) provide independent fluorescent and electrochemical signal transductions in the presence of the organophosphorus (OP) pesticides; fenthion, malathion and ethion. The presence of the methyl groups at the 3 and 6 positions in DM-BDPPZ was found to significantly influence the sensor performance. The difference in the fluorescence and electrochemical signals produced by the interaction of the sensor compound with each of the OP pesticides provides a means for differentiating between the three pesticides. Detection limits of 10(-8)M, 10(-9) and 10(-12)M were obtained for fenthion, malathion and ethion, respectively. Due to the high sensitivity and ability to minimize false positives these new sensors will be useful for potential integration for future environmental use.
authors.affiliation: Department of Chemistry, Western Michigan University, 1903, W. Michigan Avenue, Kalamazoo, MI 49008-5413, United States.
authors.forename: Wen
authors.initials: W
authors.lastname: Guo
authors.forename: Brigitte J
authors.initials: BJ
authors.lastname: Engelman
authors.forename: Tajay L
authors.initials: TL
authors.lastname: Haywood
authors.forename: Neil B
authors.initials: NB
authors.lastname: Blok
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Beaudoin
authors.forename: Sherine O
authors.initials: SO
authors.lastname: Obare
mesh_terms: D002800:Cholinesterase Inhibitors / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods; D005284:Fenthion / Q000032:analysis*; D008294:Malathion / Q000032:analysis*; D009946:Organothiophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D010619:Phenazines / Q000737:chemistry; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D002800:Cholinesterase Inhibitors; D009946:Organothiophosphorus Compounds; D010575:Pesticides; D010619:Phenazines; C443807:benzodipyrido(3,2-a-2',3'-c)phenazine; C100038:ethion; D005284:Fenthion; D008294:Malathion