A multicolor colorimetric assay for sensitive detection of sulfide ions based on anti-etching of triangular gold nanoplates
A multicolor colorimetric assay for sensitive detection of sulfide ions based on anti-etching of triangular gold nanoplates
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DOI：
10.1016/j.microc.2020.105429
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发表时间：
2020-12
影响因子：
4.8
通讯作者：
Qian Wang;Yishan Wang;Mengting Guan;Shouzhe Zhu;Xiaoxia Yan;Y. Lei;Xia Shen;Liqiang Luo;
中科院分区：
文献类型：
--
作者：
Qian Wang;Yishan Wang;Mengting Guan;Shouzhe Zhu;Xiaoxia Yan;Y. Lei;Xia Shen;Liqiang Luo;
This study presents a viable colorimetric assay for sensitive sensing of sulfide ions (S2−) using triangular gold nanoplates (AuNPLs) as nanoprobes. The sensing mechanism is based on regulating the etching process of AuNPLs upon the addition of different concentration of S2−. In the presence of Cu2+and I−, the AuNPLs would be etched by triiodide ions (I3−) produced from the redox reaction between Cu2+and I−, resulting in the transformation of the shape of AuNPLs from triangular into sphere and blue shifted localized surface plasmon resonance (LSPR). However, in the presence of S2−, a preferential reaction between Cu2+and S2−occurred, and the inhibition of the formation of I3−prevented the AuNPLs from being etched. Correspondingly, a red shift of LSPR can be observed with an increase of the concentration of S2−, accompanying a readily distinguishable color transition that goes from pink to purplish red, purple, bluish purple and blue. The color alterations allow for a visual estimation of the concentrations of S2−, and the lowest visual concentration through naked-eyes was 0.1 μM. A good linear relationship (R2= 0.997) between the peak shifts and the concentration of S2−was obtained in the range of 0.02–1.5 μM, and the limit of detection (3 s/k) by UV–vis spectroscopy was as low as 16 nM. The as-established assay displayed excellent selectivity, which was successfully applied for analysis of S2−in environmental water samples.
