CONDUCTOMETRIC BIOSENSORS BASED ON CHOLINESTERASES FOR SENSITIVE DETECTION OF PESTICIDES
CONDUCTOMETRIC BIOSENSORS BASED ON CHOLINESTERASES FOR SENSITIVE DETECTION OF PESTICIDES
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DOI：
10.1002/elan.1140060907
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发表时间：
1994-09-01
期刊：
影响因子：
3
通讯作者：
MARTELET, C
中科院分区：
文献类型：
--
作者：
DZYDEVICH, SV;SHULGA, AA;MARTELET, C
将乙酰胆碱酯酶和丁基胆碱酯酶(BUCHS)固定在叉指电极上，制备了一次性电导微生物传感器。以牛血清白蛋白为交联剂对酶进行固定化，记录了覆盖有酶膜的电极对和只覆盖白蛋白的电极对的产量差异。在此基础上，建立了液体中农药的生化检测方法。对氟磷二异丙酯的检出限为5×10~(-11)M，敌百虫的检出限为10~(-7)M，甲基对氧磷和对氧磷乙酯的检出限为10~(-6)M。样品中农药含量超过检出限仅需孵育10分钟即可检出，但为了扩大测定范围，提高测定准确度，孵育时间最好超过30分钟。使用甲基吡啶-2-缩醛亚胺作为复活剂，使人能够在低浓度农药溶液中孵化传感器响应的完全恢复，例如在低浓度农药溶液中孵育，例如在10(-5)M甲基对氧磷溶液中孵育10-20分钟，在很短的时间内，例如10-20分钟，就可以完全恢复传感器响应。
Disposable conductometric microbiosensors based on immobilization of acetyl and butyrylcholinesterases (BuChEs) on interdigitated electrodes were fabricated. Enzymes were immobilized by crosslinking with bovine serum albumin and the differential output between the pair of electrodes covered with the enzyme membrane and the pair covered with albumin only was recorded. On the basis of these biosensors, a biochemical assay for pesticides in liquids was developed. Respective detection limits were 5 x 10(-11) M for diisopropyl fluorophosphate (DFP), 10(-7) M for trichlorfon, and 10(-6) M for paraoxon-methyl and paraoxon-ethyl for the assays based on the enzymes tested. The presence of pesticides in the sample in concentration exceeding the detection limits can be detected after only 10 minutes of incubation, whereas, in order to extend the range of the determined pesticide concentration and to improve the accuracy of the assay, it is better to use incubation times longer than 30 minutes. Use of pyridin-2-aldoximide methiodide as reactivating agent allowed one to achieve the complete recovery of the sensor response when it was incubated in low-concentrated pesticide solutions, e.g., less than 10(-6) M for paraoxon-methyl and during a short rime, e.g., 10 to 20 minutes, for 10(-5) M paraoxon-methyl solution.