Rapid, selective, and in situ detection of pertechnetate (TcO4-) in multicomponent matrices consisting of interfering anions such as the ubiquitous NO3- and Cl- or the isostructural CrO42- is challenging. Present sensors lack the selectivities to exclude these interferences or the sensitivities to meet detection limits that are lower than the drinking water standards across the globe. This work presents an affinity-based electrochemical sensor for TcO4- detection that relies on selective reductive precipitation of aqueous TcO4- induced by a 1,4-benzenedimethanethiol capture probe immobilized on an electrode platform. This results in a direct decrease in the electron transfer current, the magnitude of the decrease being proportional to the amount of TcO4- added. Using this approach, a detection limit of 1 × 10-10 M was achieved, which is lower than the drinking water standard of 5.2 × 10-10 M set by United States Environmental Protection Agency. The proposed approach shows selectivity to the TcO4- anion, allowing detection of TcO4- from a multicomponent groundwater sample obtained from a well at the Hanford site in Washington (well 299-W19-36) that also contained NO3-, Cl-, and CrO42-, without discernably affecting the detection limits.

中文翻译：

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基于氧化还原的电化学亲和传感器，用于检测高tech酸根阴离子。

在由干扰阴离子（如普遍存在的NO3-和Cl-或同构CrO42-）组成的多组分基质中，快速，选择性和就地检测高tech酸酯（TcO4-）具有挑战性。当前的传感器缺乏排除这些干扰的选择性，或者缺乏满足低于全球饮用水标准的检测极限的灵敏度。这项工作提出了一种用于TcO4-检测的基于亲和力的电化学传感器，该传感器依赖于固定在电极平台上的1,4-苯二甲硫醇捕获探针诱导的TcO4-水溶液的选择性还原沉淀。这导致电子传输电流直接减小，减小的幅度与添加的TcO4-的量成正比。使用这种方法，检测极限达到了1×10-10 M，低于美国环境保护局设定的饮用水标准5.2×10-10M。拟议的方法显示出对TcO4-阴离子的选择性，从而可以从多组分地下水样品中检测TcO4-，该样品取自华盛顿州汉福德工地的一口井（299-W19-36井），其中还含有NO3-，Cl-和CrO42 -不会明显影响检测极限。