title: Screen-printed electrode based on AChE for the detection of pesticides in presence of organic solvents.
abstract: A screen-printed biosensor for the detection of pesticides in water miscible organic solvents is described based on the use of p-aminophenyl acetate as acetylcholinesterase substrate. The oxidation of p-aminophenol, product of the enzymatic reaction was monitored at 100 mV vs. Ag/AgCl screen-printed reference electrode. Miscible organic solvents as ethanol and acetonitrile were tested. The acetylcholinesterase (AChE) was immobilised on a screen-printed electrode surface by entrapment in a PVA-SbQ polymer and the catalytic activity of immobilised AChE was studied in the presence of different percentages of organic solvents in buffer solution. The sensor shows good characteristics when experiments were performed in concentrations of organic solvents below 10%. No significant differences were observed when working with 1 and 5% acetonitrile in the reaction media. Detection limits as low as 1.91x10(-8) M paraoxon and 1.24x10(-9) M chlorpyrifos ethyl oxon were obtained when experiments are carried out in 5% acetonitrile.
authors.affiliation: Centre de Phytopharmacie, Université de Perpignan-UMR CNRS 5054, 52, Avenue de Villeneuve, 66860 Perpignan Cedex, France; University of Bucharest, Faculty of Chemistry, Department of Analytical Chemistry, 90-92 Panduri, 76234, Bucharest, Romania.
authors.forename: Silvana
authors.initials: S
authors.lastname: Andreescu
authors.forename: Thierry
authors.initials: T
authors.lastname: Noguer
authors.forename: Vasile
authors.initials: V
authors.lastname: Magearu
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Marty