Calvo-Pérez Ana, Domínguez-Renedo Olga, Alonso-Lomillo M Asunción, Arcos-Martínez M Julia
Department of Chemistry, Faculty of Sciences, University of Burgos, Plaza Misael Bañuelos s/n, Burgos 09001, Spain.
Anal Chim Acta. 2014 Jun 23;833:15-21. doi: 10.1016/j.aca.2014.05.006. Epub 2014 May 13.
Chronoamperometric assays based on tyrosinase and glucose oxidase (GOx) inactivation have been developed for the monitoring of Cr(III) and Cr(VI). Tyrosinase was immobilized by crosslinking on screen-printed carbon electrodes (SPCEs) containing tetrathiafulvalene (TTF) as electron transfer mediator. The tyrosinase/SPC(TTF)E response to pyrocatechol is inhibited by Cr(III). This process, that is not affected by Cr(VI), allows the determination of Cr(III) with a capability of detection of 2.0±0.2 μM and a reproducibility of 5.5%. GOx modified screen-printed carbon platinised electrodes (SPCPtEs) were developed for the selective determination of Cr(VI) using ferricyanide as redox mediator. The biosensor was able to discriminate two different oxidation states of chromium being able to reject Cr(III) and to detect the toxic species Cr(VI). Chronoamperometric response of the biosensor towards glucose decreases with the presence of Cr(VI), with a capability of detection of 90.5±7.6 nM and a reproducibility of 6.2%. A bipotentiostatic chronoamperometric biosensor was finally developed using a tyrosinase/SPC(TTF)E and a GOx/SPC(Pt)E connected in array mode for the simultaneous determination of Cr(III) and Cr(VI) in spiked tap water and in waste water from a tannery factory samples.
基于酪氨酸酶和葡萄糖氧化酶（GOx）失活的计时电流分析法已被开发用于监测Cr(III)和Cr(VI)。通过交联将酪氨酸酶固定在含有四硫富瓦烯（TTF）作为电子转移介质的丝网印刷碳电极（SPCE）上。Cr(III)会抑制酪氨酸酶/SPC(TTF)E对邻苯二酚的响应。此过程不受Cr(VI)影响，可用于测定Cr(III)，检测限为2.0±0.2 μM，重现性为5.5%。开发了用铁氰化物作为氧化还原介质的GOx修饰的丝网印刷碳铂电极（SPCPtE）用于选择性测定Cr(VI)。该生物传感器能够区分铬的两种不同氧化态，能够排除Cr(III)并检测有毒物质Cr(VI)。生物传感器对葡萄糖的计时电流响应会因Cr(VI)的存在而降低，检测限为90.5±7.6 nM，重现性为6.2%。最终开发了一种双恒电位计时电流生物传感器，它使用以阵列模式连接的酪氨酸酶/SPC(TTF)E和GOx/SPC(Pt)E，用于同时测定加标自来水和制革厂废水样品中的Cr(III)和Cr(VI)。
