Step-by-Step Design and Synthesis of Au@SiO(2)@Phenyl-azathiacrown for SERS-Based Specific Quantification of Inorganic Mercury.
Step-by-Step Design and Synthesis of Au@SiO(2)@Phenyl-azathiacrown for SERS-Based Specific Quantification of Inorganic Mercury.
复制标题
用于基于 SERS 的无机汞特异性定量的 Au@SiO2@Phenyl-azathiacrown 的逐步设计和合成
DOI：
10.1002/open.201600135
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发表时间：
2017-04
期刊：
影响因子：
2.3
通讯作者：
Wang Q
中科院分区：
文献类型：
--
作者：
Wu Y;Yang L;Wang Q
基于SERS的无机金属物种的直接定量一直是一个问题，因为它们的拉曼截面很小，甚至没有振动模。在这里，我们报告了一种基于表面增强拉曼散射对这类金属物种进行量化的新策略，例如水中的无机汞(HgII)。从氮杂硫醚[3，9-二硫-6-氮杂十一烷和3，6，12，15-四硫-9-一氮杂十七烷]到氮杂冠醚[7-氮杂-1，4，10，13-四硫杂环十六烷(NS4)]的逐步设计和合成证明了改进的S拉动效应和对HgII形成汞−S键的尺寸匹配专一性。用4-溴甲基苯甲酸连接物修饰Au@SiO_2表面的Sn4，首次实现了基于表面增强拉曼散射的直接特异性定量HgII，其中覆盖在Au核(55 nm)上的超薄的一层(约2 nm)可能是阻止Au核与HgII直接作用的屏障，并以苯作内标(IS)。Hg−S在270 cm−1处的表面增强拉曼散射带强度与IS[(γCC+γccc)在1046 cm−1处的SERS谱带强度之比]几乎与HgII的浓度成正比，消除了基于表面增强拉曼光谱测量中不可避免的不确定因素。当设计了特定的络合底物和合适的ISS时，这种方法有望为基于SERS的无机金属物种的定量铺平一条新的道路。
Direct SERS‐based quantification of inorganic metal species has been a problem, because they have a small Raman cross‐section or even no vibrational mode. Here, we report a new strategy for SERS‐based quantification of such metal species, as exemplified by inorganic mercury (HgII) in waters. Step‐by‐step design and synthesis from azathioethers [3, 9‐dithia‐6‐monoazaundecane (DMA) and 3,6,12,15‐tetrathia‐9‐monoazaheptadecane (TTM)] to an azathiacrown [7‐aza‐1,4,10,13‐tetrathiacyclohexadecane (NS4)] demonstrate an improved S‐pulling effect and size‐fit specificity towards HgII to form Hg−S bonds. Modification of NS4 on the surface of Au@SiO2 by using a 4‐(bromomethyl)benzoic linker enabled direct SERS‐based specific quantification of HgII for the first time, in which the ultrathin layer (ca. 2 nm) that covered the Au core (55 nm) could be a barrier preventing the Au core from having direct interaction with the HgII, and with phenyl serving as an internal standard (IS). The ratio of the Hg−S SERS band intensity at 270 cm−1 to that of IS [(γCC+γCCC) at 1046 cm−1] was practically proportional to the concentration of HgII, eliminating the inevitable uncertainties encountered in SERS‐based measurements. Such a methodology is expected to pave a new way for SERS‐based quantification of inorganic metal species when specific complexing substrates and suitable ISs are designed.