Somerset V, Baker P, Iwuoha E
Council for Scientific and Industrial Research (CSIR), Natural Resources and the Environment (NRE), Stellenbosch, South Africa.
J Environ Sci Health B. 2009 Feb;44(2):164-78. doi: 10.1080/03601230802599092.
This paper reports the construction of the gold/mercaptobenzothiazole/polyaniline/acetylcholinesterase/polyvinylacetate (Au/ MBT/PANI/AChE/PVAc) thick-film biosensor for the determination of certain organophosphate pesticide solutions in selected aqueous organic solvent solutions. The Au/MBT/PANI/AChE/PVAc electrocatalytic biosensor device was constructed by encapsulating acetylcholinesterase (AChE) enzyme in the PANI polymer composite, followed by the coating of poly(vinyl acetate) (PVAc) on top to secure the biosensor film from disintegration in the organic solvents evaluated. The electroactive substrate called acetylthiocholine (ATCh) was employed to provide the movement of electrons in the amperometric biosensor. The voltammetric results have shown that the current shifts more anodically as the Au/MBT/PANI/AChE/PVAc biosensor responded to successive acetylthiocholine (ATCh) substrate addition under anaerobic conditions in 0.1 M phosphate buffer, KCl (pH 7.2) solution and aqueous organic solvent solutions. For the Au/MBT/PANI/AChE/PVAc biosensor, various performance and stability parameters were evaluated. These factors include the optimal enzyme loading, effect of pH, long-term stability of the biosensor, temperature stability of the biosensor, the effect of polar organic solvents, and the effect of non-polar organic solvents on the amperometric behavior of the biosensor. The biosensor was then applied to detect a series of 5 organophosphorous pesticides in aqueous organic solvents and the pesticides studied were parathion-methyl, malathion and chlorpyrifos. The results obtained have shown that the detection limit values for the individual pesticides were 1.332 nM (parathion-methyl), 0.189 nM (malathion), 0.018 nM (chlorpyrifos).
本文报道了用于测定特定水相有机溶剂溶液中某些有机磷酸酯农药溶液的金/巯基苯并噻唑/聚苯胺/乙酰胆碱酯酶/聚醋酸乙烯酯（Au/MBT/PANI/AChE/PVAc）厚膜生物传感器的构建。Au/MBT/PANI/AChE/PVAc电催化生物传感器装置的构建方法是，将乙酰胆碱酯酶（AChE）封装在聚苯胺聚合物复合材料中，然后在顶部涂覆聚醋酸乙烯酯（PVAc），以确保生物传感器膜在评估的有机溶剂中不会分解。使用称为乙酰硫代胆碱（ATCh）的电活性底物来提供电流型生物传感器中的电子移动。伏安法结果表明，在0.1 M磷酸盐缓冲液、KCl（pH 7.2）溶液和水相有机溶剂溶液中，在厌氧条件下，随着Au/MBT/PANI/AChE/PVAc生物传感器对连续添加的乙酰硫代胆碱（ATCh）底物作出响应，电流向阳极方向移动得更多。对于Au/MBT/PANI/AChE/PVAc生物传感器，评估了各种性能和稳定性参数。这些因素包括最佳酶负载量、pH值的影响、生物传感器的长期稳定性、生物传感器的温度稳定性、极性有机溶剂的影响以及非极性有机溶剂对生物传感器电流行为的影响。然后将该生物传感器应用于检测水相有机溶剂中的一系列5种有机磷农药，所研究的农药为甲基对硫磷、马拉硫磷和毒死蜱。所得结果表明，各农药的检测限分别为1.332 nM（甲基对硫磷）、0.189 nM（马拉硫磷）、0.018 nM（毒死蜱）。
