Ultra-sensitive conductometric detection of pesticides based on inhibition of esterase activity in Arthrospira platensis.

Abstract : Enzymatic conductometric biosensor, using immobilized Arthrospira platensis cells on gold interdigitated electrodes, for the detection of pesticides in water, was elaborated. Cholinesterase activity (AChE) was inhibited by pesticides and a variation of the local conductivity was measured after addition of the substrate acetylthiocholine chloride (AChCl). The Michaelis-Menten constant (Km) was evaluated to be 1.8 mM through a calibration curve of AChCl. Inhibition of AChE was observed with paraoxon-methyl, parathion-methyl, triazine and diuron with a detection limit of 10(-18) M, 10(-20) M, 10(-20) M and 10(-12) M, respectively and the half maximal inhibitory concentration (IC50) was determined at 10(-16) M, 10(-20) M, 10(-18) M and 10(-06) M, respectively. An important decrease of response time τ90% was recorded for AChE response towards AChCl after 30 min cell exposure to pesticides. Scanning electron microscopy images revealed a degradation of the cell surface in presence of pesticides at 10(-06) M.
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Environmental Pollution, Elsevier, 2013, 178, pp.182-188. 〈10.1016/j.envpol.2013.03.013〉
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https://hal.archives-ouvertes.fr/hal-00851121
Contributeur : Agnès Bussy <>
Soumis le : lundi 12 août 2013 - 14:39:26
Dernière modification le : jeudi 7 février 2019 - 15:10:22

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Nadèje Tekaya, Olga Saiapina, Hatem Ben Ouada, Florence Lagarde, Hafedh Ben Ouada, et al.. Ultra-sensitive conductometric detection of pesticides based on inhibition of esterase activity in Arthrospira platensis.. Environmental Pollution, Elsevier, 2013, 178, pp.182-188. 〈10.1016/j.envpol.2013.03.013〉. 〈hal-00851121〉

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