AbstractThe authors present a colorimetric method for the quantification of Ni(II) at nanomolar levels. It is based on the use of iodide-responsive copper-gold nanoparticles (Cu-Au NPs) combined with the Ni(II)-catalyzed glutathione (GSH)-oxygen reaction system. In the presence of Ni(II), the catalytic reaction between GSH and oxygen is can triggered. This leads to the formation of GSSG which is bulky and hinders the access of iodide to the surface of the Cu-Au NPs. Concomitantly, the color of the solution containing the Cu-Au NPs changes from gray to red. Based on these findings, a method was developed for the quantitation of Ni(II) that has a detection limit as low as 0.54 nM. This is 1–3 orders of magnitude lower than that of previously reported optical methods. The assay has excellent selectivity for Ni(II), is rapid, cost-effective, portable, and allows for bare eye observation. Conceivably the method is suitable for field detection of Ni(II) in biological, food, and environmental samples. Graphical AbstractA sensitive colorimetric strategy for Ni(II) through the combination of iodide-responsive Cu-Au NPs with Ni(II)-catalyzed the oxidation of GSH by oxygen was presented.

中文翻译：

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使用碘响应金铜纳米粒子作为比色探针测定纳摩尔水平的镍 (II)

摘要作者提出了一种在纳摩尔水平对 Ni(II) 进行定量的比色法。它基于碘响应铜金纳米粒子 (Cu-Au NPs) 与 Ni(II) 催化的谷胱甘肽 (GSH)-氧反应系统的结合使用。在 Ni(II) 存在下，可以触发 GSH 和氧气之间的催化反应。这导致形成体积庞大的 GSSG 并阻碍碘化物进入 Cu-Au NPs 的表面。同时，含有 Cu-Au NPs 的溶液的颜色从灰色变为红色。基于这些发现，开发了一种检测限低至 0.54 nM 的 Ni(II) 定量方法。这比以前报道的光学方法低 1-3 个数量级。该测定对 Ni(II) 具有出色的选择性，快速、经济、便携、并允许裸眼观察。可以想象，该方法适用于生物、食品和环境样品中 Ni(II) 的现场检测。图形摘要通过结合碘响应的 Cu-Au NPs 与 Ni(II)-催化氧氧化 GSH，提出了 Ni(II) 的灵敏比色策略。