Highly sensitive and selective determination of iodide and thiocyanate concentrations using surface-enhanced Raman scattering of starch-reduced gold nanoparticles.
Highly sensitive and selective determination of iodide and thiocyanate concentrations using surface-enhanced Raman scattering of starch-reduced gold nanoparticles.
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DOI：
10.1021/ac200743j
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发表时间：
2011-04
影响因子：
7.4
通讯作者：
P. Pienpinijtham;X. Han;S. Ekgasit;Y. Ozaki
中科院分区：
文献类型：
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作者：
P. Pienpinijtham;X. Han;S. Ekgasit;Y. Ozaki
在本报告中，我们提出了一种利用淀粉还原金纳米颗粒表面增强拉曼散射（SERS）测定碘化物和硫氰酸盐浓度的新技术。淀粉还原金纳米粒子由于合成副产物的-C≡C-拉伸模式，在2125 cm（-1）处显示出一个本特征拉曼峰。由于碘化物在金表面的高吸附性，在2125 cm（-1）处SERS峰的强度随着碘化物浓度的增加而减小。硫氰酸盐也强烈吸附在金表面，并且在2100厘米（-1）左右出现一个新的峰，这归因于淀粉还原金纳米粒子的SERS光谱中的-C≡N拉伸振动。这两个峰被成功地用来分别测定碘化物和硫氰酸盐的浓度，甚至在它们的混合体系中。该技术对碘化物的检出限为0.01 μM，测量范围为0.01 ~ 2.0 μM；对硫氰酸盐的检出限为0.05 μM，测量范围为0.05 ~ 50 μM。该技术对碘化物和硫氰酸盐离子具有高度选择性，而不会受到其他共存阴离子（如其他卤化物、碳酸盐和硫酸盐）的干扰。
In this report, we propose a novel technique for the determination of the concentrations of iodide and thiocyanate by surface-enhanced Raman scattering (SERS) of starch-reduced gold nanoparticles. Starch-reduced gold nanoparticles show an intrinsic Raman peak at 2125 cm(-1) due to the -C≡C- stretching mode of a synthesized byproduct. Because of the high adsorptivity of iodide on a gold surface, the intensity of the SERS peak at 2125 cm(-1) decreases with an increase in the iodide concentration. Thiocyanate also strongly adsorbs on a gold surface, and a new peak appears at around 2100 cm(-1), attributed to the -C≡N stretching vibration in a SERS spectrum of starch-reduced gold nanoparticles. These two peaks were successfully used to determine the iodide and thiocyanate concentrations separately, even in their mixture system. The detection limit of this technique for iodide is 0.01 μM with a measurement range of 0.01-2.0 μM, while the detection limit of this technique for thiocyanate is 0.05 μM with a measurement range of 0.05-50 μM. This technique is highly selective for iodide and thiocyanate ions without interference from other coexisting anions such as other halides, carbonate, and sulfate.