title: Genetically engineered acetylcholinesterase-based biosensor for attomolar detection of dichlorvos.
abstract: The design of a biosensor for the detection of dichlorvos at attomolar levels is described based on a highly sensitive double mutant (E69Y Y71D) of the Drosophila melanogaster acetylcholinesterase (Dm. AChE). This enzyme has a k(i) for dichlorvos equal to 487 microM(-1)min(-1), which is 300 and 20,000 times higher than that of the wild type Dm. AChE and the Electrophorus electricus AChE (E.el. AChE), respectively. The enzyme is immobilized into microporous-activated conductive carbon, and is used as such for the development of an inhibitor electrochemical biosensor. This E69Y Y71D mutant enables the decrease in the detection limit of the biosensor down to 10(-17) M, which is five orders of magnitude lower compared to the Electropharus electricus-based biosensor and eight orders of magnitude lower than the biosensors described so far.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, Knossou Avenue, University of Crete 71409, Iraklion Crete, Greece.
authors.forename: Sofia
authors.initials: S
authors.lastname: Sotiropoulou
authors.forename: Didier
authors.initials: D
authors.lastname: Fournier
authors.forename: Nikos A
authors.initials: NA
authors.lastname: Chaniotakis
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004006:Dichlorvos / Q000032:analysis*; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004789:Enzyme Activation; D004795:Enzyme Stability; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods; D010575:Pesticides / Q000032:analysis; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000032:analysis / Q000737:chemistry
chemical_list: D010575:Pesticides; D011994:Recombinant Proteins; D004006:Dichlorvos; D000110:Acetylcholinesterase