Determination of pesticides in vegetable samples using an acetylcholinesterase biosensor based on nanoparticles ZrO2/chitosan composite film |
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| Authors: | Yunhui Yang Mengmeng Guo Minghui Yang Zhijie Wang Ruqin Yu |
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| Affiliation: | 1. State Key Laboratory for Chemo/Biosensing and Chemometrics , College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, People's Republic of China;2. College of Chemistry and Chemical Engineering , Yunnan Normal University , Kunming 650092, People's Republic of China;3. State Key Laboratory for Chemo/Biosensing and Chemometrics , College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, People's Republic of China |
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| Abstract: | An amperometric pesticides inhibition biosensor has been developed and used for determination of pesticides in vegetable samples. To eliminate the interference of ascorbic acid, multilayer films of polyelectrolyte (chitosan/polystyrensulfonate) were coated on the glass carbon electrode. Then, acetylcholinesterase was immobilized on the electrode based on surface-treated nanoporous ZrO2/chitosan composite film as immobilization matrix. As a modified substrate, acetylthiocholine was hydrolysed by acetylcholinesterase and produced thiocholine which can be oxidized at +700?mV vs. SCE. Pesticides inhibit the activity of enzyme with an effect of decreasing of oxidation current. The experimental conditions were optimized. The electrode has a linear response to acetylthiocholine within 9.90?×?10?6 to 2.03?×?10?3?M. The electrode provided a linear response over a concentration range of 6.6?×?10?6 to 4.4?×?10?4?M for phoxim with a detection limit of 1.3?×?10?6?M, over a range of 1.0?×?10?8 to 5.9?×?10?7?M for malathion, and over a range of 8.6?×?10?6 to 5.2?×?10?4?M for dimethoate. This biosensor has been used to determine pesticides in a real vegetable sample. |
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| Keywords: | Pesticides Amperometry Inhibition biosensor Acetylcholinesterase Nanoparticles ZrO2 Chitosan |
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