Insecticide identification using a flow injection analysis system with biosensors based on various cholinesterases
2005; Elsevier BV; Volume: 539; Issue: 1-2 Linguagem: Inglês
10.1016/j.aca.2005.03.026
ISSN1873-4324
AutoresBogdan Bucur, Madalina Petruta Dondoi, Andrei Florin Danet, Jean‐Louis Marty,
Tópico(s)Electrochemical Analysis and Applications
ResumoThis work presents an automatic method able to identify the presence of neurotoxic insecticides using omethoate as a model compound. The acetylcholinesterase (AChE)-based biosensors used to detect the neurotoxic insecticides present two shortcomings: the weak limit of detection (LOD) and the lack of selectivity. An appropriate LOD is obtained in our work by using two sensitive AChEs from Drosophila melanogaster (Dm): the wild type (wt-Dm) and the E69W mutant. To discriminate between the insecticides and all other interferences, we use a FIA system that provides analytical information acquired from two enzymes: (i) the sensitive Dm-AChEs and (ii) an omethoate-resistant AChE from Electric Eel (Eel), which is equally affected by the matrix. The enzymes were immobilised on screen-printed electrodes by entrapment in a photocrosslinkable PVA-SbQ polymer used with a FIA system with three channels, each one of them simultaneously analysing the same sample using biosensors based on different AChEs. The biosensor based on the wt-Dm had a LOD of 2 × 10−6 M omethoate, while the one based on the E69W mutant permitted to lower the LOD to 1 × 10−7 M. Interferences produced by mercury and hypocloryte were successfully discriminated. Environmental water samples were also analysed.
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