Insecticide identification using a flow injection analysis system with biosensors based on various cholinesterases [An article from: Analytica Chimica Acta]
Book Details
PublisherElsevier
ISBN / ASINB000RR3IEQ
ISBN-13978B000RR3IE3
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Description
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
This 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 2x10^-^6M omethoate, while the one based on the E69W mutant permitted to lower the LOD to 1x10^-^7M. Interferences produced by mercury and hypocloryte were successfully discriminated. Environmental water samples were also analysed.
Description:
This 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 2x10^-^6M omethoate, while the one based on the E69W mutant permitted to lower the LOD to 1x10^-^7M. Interferences produced by mercury and hypocloryte were successfully discriminated. Environmental water samples were also analysed.
