Department of Chemistry, Capital Normal University , Beijing, 100048, China.
College of Resources Environment and Tourism, Capital Normal University , Beijing, 100048, China.
Anal Chem. 2015 Nov 3;87(21):10963-8. doi: 10.1021/acs.analchem.5b02812. Epub 2015 Oct 13.
Mercury is a major threat to the environment and to human health. It is highly desirable to develop a user-friendly kit for on-site mercury detection. Such a method must be able to detect mercury below the threshold levels (10 nM) for drinking water defined by the U.S. Environmental Protection Agency. Herein, we for the first time reported catalytically active gold amalgam-based reaction between 4-nitrophenol and NaBH4 with colorimetric sensing function. We take advantage of the correlation between the catalytic properties and the surface area of gold amalgam, which is proportional to the amount of the gold nanoparticle (AuNP)-bound Hg(2+). As the concentration of Hg(2+) increases until the saturation of Hg onto the AuNPs, the catalytic performance of the gold amalgam is much stronger due to the formation of gold amalgam and the increase of the nanoparticle surface area, leading to the decrease of the reduction time of 4-nitrophenol for the color change. This sensing system exhibits excellent selectivity and ultrahigh sensitivity up to the 1.45 nM detection limit. The practical use of this system for Hg(2+) determination in tap water samples is also demonstrated successfully.
汞是对环境和人类健康的主要威胁。开发一种用于现场汞检测的用户友好型试剂盒是非常可取的。这种方法必须能够检测到美国环境保护署定义的饮用水中低于阈值（10 nM）的汞。在这里，我们首次报道了基于金汞齐的 4-硝基苯酚与 NaBH4 之间的催化活性反应，具有比色传感功能。我们利用金汞齐的催化性质与表面积之间的相关性，该相关性与结合在 AuNP 上的 Hg(2+)的量成正比。随着 Hg(2+)浓度的增加，直到 AuNPs 上的 Hg 达到饱和，由于金汞齐的形成和纳米粒子表面积的增加，金汞齐的催化性能大大增强，导致 4-硝基苯酚的还原时间减少，颜色发生变化。该传感系统表现出优异的选择性和超高的灵敏度，检测限低至 1.45 nM。还成功地证明了该系统在自来水中 Hg(2+)测定中的实际应用。
