Facile Colorimetric Detection of Silver Ions with Picomolar Sensitivity
Facile Colorimetric Detection of Silver Ions with Picomolar Sensitivity
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DOI：
10.1021/acs.analchem.6b05026
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发表时间：
2017-03-21
影响因子：
7.4
通讯作者：
Xia, Xiaohu
中科院分区：
文献类型：
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作者：
Gao, Zhuangqiang;Liu, Grace G.;Xia, Xiaohu
尽管各种比色法因其简单、可靠而被广泛应用于银离子的检测，但这些方法的检测极限仅限于纳米级。在这里，我们展示了一种新的策略，以皮摩尔(PM)灵敏度比色检测银离子。这一策略包括使用聚乙烯吡咯烷酮(PVP-)封顶的铂纳米立方体作为人工过氧化物酶，通过催化过氧化物酶底物的氧化有效地产生有色信号。在Ag+离子的存在下，由于Ag+对铂的过氧化物酶样活性的特异性和高效的抑制作用，这些铂立方体产生的有色信号大大减弱。该比色法的检出限为80 pm，动态范围为10(-2)-10(4)nm。据我们所知，在所有已报道的比色方法中，本工作提出的方法显示出对Ag+检测的最高灵敏度。此外，该方法还具有简单、快速的特点，因为它可以在室温下在水溶液中进行，所需时间仅相当于6分钟。
Although various colorimetric methods have been actively developed for the detection of Ag+ ions because of their simplicity and reliability, the limits of detection of these methods are confined to the nanomolar (nM) level. Here, we demonstrate a novel strategy for colorimetric Ag+ detection with picomolar (pM) sensitivity. This strategy involves the use of poly(vinylpyrrolidone)- (PVP-) capped Pt nanocubes as artificial peroxidases that can effectively generate a colored signal by catalyzing the oxidation of peroxidase substrates. In the presence of Ag+ ions, the colored signal generated by these Pt cubes is greatly diminished because of the specific and efficient inhibition of Ag+ toward the peroxidase-like activity of the Pt cubes. This colorimetric method can achieve an ultralow detection limit of 80 pM and a wide dynamic range of 10(-2)-10(4) nM. To the best of our knowledge, the method presented in this work shows the highest sensitivity for Ag+ detection among all reported colorimetric methods. Moreover, this method also features simplicity and rapidness as it can be conducted at room temperature, in aqueous solution, and requires only similar to 6 min.