Department of Chemistry, National Taiwan Normal University, Taipei, 116, Taiwan.
Department of Chemistry, National Taiwan Normal University, Taipei, 116, Taiwan.
Anal Chim Acta. 2022 Sep 22;1227:340335. doi: 10.1016/j.aca.2022.340335. Epub 2022 Aug 30.
Hexavalent chromium ions (Cr(VI)) are highly toxic and prone to bioaccumulation in the natural environment. This study sought to develop a facile and cost-effective approach to on-site monitoring Cr(VI) content in diverse environmental samples. We synthesized copper-based MOF nanozymes (Cu-PyC MOF) and developed a simple colorimetric method by which to detect Cr(VI) on paper-based devices. The colorimetric product is obtained using the MOF nanozyme as a catalyst, Cr(VI) as an oxidant, 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate to produce a bluish-green color observable by the naked eye or a UV-visible spectrophotometer. After Cu-PyC MOF was suspended in an acidic buffer, it remained stable and showed oxidoreductase-like catalytic activity, which in turn boosts Cr(VI) reduction. The proposed scheme enables the detection of Cr(VI) within 3 min over a linear range of 0.5-50 μM with a low detection limit of 0.051 μM. The proposed nanozyme-based colorimetric method exhibits excellent reusability and selectivity over other 27 interference ions and can be used in real sample analysis.
六价铬离子（Cr(VI)）毒性高，易于在自然环境中生物累积。本研究旨在开发一种简便、经济有效的方法，用于现场监测不同环境样品中的 Cr(VI)含量。我们合成了基于铜的 MOF 纳米酶（Cu-PyC MOF），并开发了一种简单的比色法，用于在基于纸张的设备上检测 Cr(VI)。比色产物是通过 MOF 纳米酶作为催化剂、Cr(VI)作为氧化剂、3,3',5,5'-四甲基联苯胺（TMB）作为显色底物生成的，肉眼或紫外-可见分光光度计可观察到蓝绿色。Cu-PyC MOF 悬浮在酸性缓冲液中后保持稳定，并表现出氧化还原酶样的催化活性，从而促进 Cr(VI)的还原。在所提出的方案中，Cr(VI)可以在 3 分钟内检测到，线性范围为 0.5-50 μM，检测限低至 0.051 μM。该基于纳米酶的比色法在其他 27 种干扰离子的分析中表现出优异的可重复使用性和选择性，可用于实际样品分析。
