Publication: Paper-based Acetylcholinesterase Inhibition Assay Combining a Wet System for Organophosphate and Carbamate Pesticides Detection
9
Issued Date
2015-02-26
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eng
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EXCLI Journal
Bibliographic Citation
EXCLI Journal. Vol.14, 2015, 307-319
Suggested Citation
Amara Apilux, Chartchalerm Isarankura-Na-Ayudhya, Virapong Prachayasittikul, Tanawut Tantimongcolwat Paper-based Acetylcholinesterase Inhibition Assay Combining a Wet System for Organophosphate and Carbamate Pesticides Detection. EXCLI Journal. Vol.14, 2015, 307-319. Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/2084
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Title
Paper-based Acetylcholinesterase Inhibition Assay Combining a Wet System for Organophosphate and Carbamate Pesticides Detection
Abstract
A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health
and safety. Here, a paper-based sensor combined with a wet system was developed for the simple and rapid
screening of organophosphate (OP) and carbamate (CM) pesticides based on the inhibition of acetylcholinesterase
(AChE). The paper-based sensor was designed as a foldable device consisting of a cover and detection sheets
pre-prepared with indoxyl acetate and AChE, respectively. The paper-based sensor requires only the incubation
of a sample on the test zone for 10 minutes, followed by closing of the foldable sheet to initiate the enzymatic
reaction. Importantly, the buffer loading hole was additionally designed on the cover sheet to facilitate the interaction
of the coated substrate and the immobilized enzyme. This subsequently facilitates the mixing of indoxyl
acetate with AChE, resulting in the improved analytical performance of the sensor. The absence or decrease in
blue color produced by the AChE hydrolysis of indoxyl acetate can be observed in the presence of OPs and
CMs. Under optimized conditions and using image analysis, the limit of detection (LOD) of carbofuran, dichlorvos,
carbaryl, paraoxon, and pirimicarb are 0.003, 0.3, 0.5, 0.6, and 0.6 ppm, respectively. The assay could be
applied to determine OP and CM residues in spiked food samples. Visual interpretation of the color signal was
clearly observed at the concentration of 5 mg/kg. Furthermore, a self-contained sample pre-concentration approach
greatly enhanced the detection sensitivity. The paper-based device developed here is low-cost, requires
minimal reagents and is easy to handle. As such, it would be practically useful for pesticide screening by nonprofessional
end-users.