High sensitive bienzymic sensor for the detection of dithiocarbamate fungicides
High sensitive bienzymic sensor for the detection of dithiocarbamate fungicides
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DOI：
10.1016/s0003-2670(97)00127-x
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发表时间：
1997-07-30
影响因子：
6.2
通讯作者：
Marty, JL
中科院分区：
文献类型：
--
作者：
Noguer, T;Marty, JL
基于乙醛脱氢酶抑制作用，研制了一种测定二硫代氨基甲酸酯类杀菌剂的双酶传感器。由乙醛脱氢酶氧化丙醛形成的NADH被黄递酶再氧化，使用六氰合铁（III）作为电子受体。在250 mV vs. SCE的电位下电化学氧化所产生的六氰高铁酸盐（II）。由于二硫代氨基甲酸酯类杀菌剂抑制乙醛脱氢酶，因此诱导电流的降低与它们在工作介质中的浓度有关。醛脱氢酶和心肌黄酶用于溶液中或包埋在具有苯乙烯基吡啶基团的可光交联的聚（乙烯醇）中。最好的结果是实现使用包埋酶和传感器的灵敏度提高，通过降低酶的量，并通过增加农药和酶之间的接触时间。使用包埋酶，实现了1.48 ppb的maneb的检测，而常用的分光光度法允许检测只有400 ppb的二硫代氨基甲酸盐。
A bienzymic sensor for the determination of dithiocarbamate fungicides was developed based on aldehyde dehydrogenase inhibition. The NADH formed by the oxidation of propionaldehyde by aldehyde dehydrogenase was reoxidised by diaphorase using hexacyanoferrate(III) as electron acceptor. The hexacyanoferrate(II) produced was electrochemically oxidised at a potential of 250 mV vs. SCE. As dithiocarbamate fungicides inhibit aldehyde dehydrogenase, a decrease of the induced current was correlated to their concentration in the working medium. Aldehyde dehydrogenase and diaphorase were used in solution or entrapped in a photocrosslinkable poly(vinyl alcohol) bearing styrylpyridinium groups. The best results were achieved using entrapped enzymes and the sensitivity of the sensor was improved by lowering the amount of enzyme and by increasing the contact time between the pesticide and the enzyme. Using entrapped enzymes, the detection of 1.48 ppb of maneb was achieved whereas the commonly used spectrophotometric method allows to detect only 400 ppb of dithiocarbamate.