Surface-Enhancement Raman Scattering Sensing Strategy for Discriminating Trace Mercuric Ion (II) from Real Water Samples in Sensitive, Specific, Recyclable, and Reproducible Manners

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• 作者：Bin Sun ; Xiangxu Jiang ; Houyu Wang ; Bin Song ; Ying Zhu ; Hui Wang ; Yuanyuan Su ; Yao He
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：January 20, 2015
• 年：2015
• 卷：87
• 期：2
• 页码：1250-1256
• 全文大小：553K
• ISSN：1520-6882

文摘

It is of essential importance to precisely probe mercury(II) (Hg²⁺) ions for environment-protection analysis and detection. To date, there still remain major challenges for accurate, specific, and reliable detection of Hg²⁺ ions at subppt level. We herein employ gold nanoparticles (AuNPs) decorated silicon nanowire array (SiNWAr) as active surface-enhanced Raman scattering (SERS) substrates to construct a high-performance sensing platform assisted by DNA technology, enabling ultrasensitive detection of trace Hg²⁺ in 鈭?4 min and with low sample consumption (鈭?0 渭L). Typically, strong SERS signals could be detected when the single-stranded DNA structure converts to the hairpin structure in the presence of Hg²⁺ ions, due to the formation of thymine (T)-Hg²⁺-T. As a result, Hg²⁺ ions with a low concentration of 1 pM (0.2 ppt) can be readily discriminated, much lower than those (鈭糿M) reported for conventional analytical strategies. Water samples spiked with various Hg²⁺ concentrations are further tested, exhibiting a good linear relationship between the normalized Raman intensities and the logarithmic concentrations of Hg²⁺ ranging from 1 pM to 100 nM, with a correlation coefficient of R² = 0.998. In addition, such SERS sensor features excellent selectivity, facilely distinguishing Hg²⁺ ions from various interfering substances. Moreover, this presented SERS sensor possesses good recyclability, preserving adaptable reproducibility during 5-time cyclic detection of Hg²⁺. Furthermore, unknown Hg²⁺ concentration in river water can be readily determined through our sensing strategy in accurate and reliable manners, with the RSD value of 鈭?%.