title: Electrochemical detection of carbamate pesticides in fruit and vegetables with a biosensor based on acetylcholinesterase immobilised on a composite of polyaniline-carbon nanotubes.
abstract: A sensitive electrochemical acetylcholinesterase (AChE) biosensor was successfully developed on polyaniline (PANI) and multi-walled carbon nanotubes (MWCNTs) core-shell modified glassy carbon electrode (GC), and used to detect carbamate pesticides in fruit and vegetables (apple, broccoli and cabbage). The pesticide biosensors were applied in the detection of carbaryl and methomyl pesticides in food samples using chronoamperometry (CA). The GC/MWCNT/PANI/AChE biosensor exhibited detection limits of 1.4 and 0.95μmolL(-1), respectively, for carbaryl and methomyl. These detection limits were below the allowable concentrations set by Brazilian regulation standards for the samples in which these pesticides were analysed. Reproducibility and repeatability values of 2.6% and 3.2%, respectively, were obtained in the conventional procedure. The proposed biosensor was successfully applied in the determination of carbamate pesticides in cabbage, broccoli and apple samples without any spiking procedure. The obtained results were in full agreement with those from the HPLC procedure.
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, São Paulo CEP 13566-590, Brazil. ivana@iqsc.usp.br
authors.forename: Ivana
authors.initials: I
authors.lastname: Cesarino
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Moraes
authors.forename: Marcos R V
authors.initials: MR
authors.lastname: Lanza
authors.forename: Sergio A S
authors.initials: SA
authors.lastname: Machado
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002219:Carbamates / Q000032:analysis*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry; D010575:Pesticides / Q000032:analysis*; D014675:Vegetables / Q000737:chemistry*
chemical_list: D002219:Carbamates; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D010575:Pesticides; D000110:Acetylcholinesterase