A SERS biosensor with magnetic substrate CoFe2O4@Ag for sensitive detection of Hg2+
A SERS biosensor with magnetic substrate CoFe2O4@Ag for sensitive detection of Hg2+
复制标题
具有磁性基底 CoFe2O4@Ag 的 SERS 生物传感器，用于灵敏检测 Hg2
DOI：
10.1016/j.apsusc.2017.04.106
复制
发表时间：
2017
影响因子：
6.7
通讯作者：
Yuan Ruo
中科院分区：
文献类型：
--
作者：
Yang Xia;He Yi;Wang Xueling;Yuan Ruo
汞离子（Hg ~（2+））是存在于水生生态系统中的一种有毒金属离子，对人体中枢神经系统等器官有严重的损害作用。因此，研究一种灵敏检测环境中Hg 2+的方法具有重要的现实意义。基于胸腺嘧啶-汞离子-胸腺嘧啶（T-Hg 2 +-T）的稳定结构和单链DNA（ssDNA）与单壁碳纳米管（SWCNTs）之间的π-π相互作用，制备了一种新型的表面增强拉曼光谱（Sers）传感器，用于水溶液中汞离子的高选择性和超灵敏检测。在本文中，SWCNT充当拉曼标记物以产生特征拉曼峰，其可以是定量检测Hg 2+的信标。在Hg 2+存在下，ssDNA可以捕获Hg 2+，形成T-Hg 2 +-T结构，使单壁碳纳米管离开SERS传感器的热点。在这种设计下，单壁碳纳米管的拉曼强度随着Hg 2+浓度的增加而降低。同时，CoFe2O4@Ag作为Sers活性基底，通过磁性聚集，可以有效提高传感器的灵敏度和均匀性。在最佳条件下，该传感器可检测1 pM ~ 100 nM范围内的Hg ~（2+），检测限为0.84 pM。该传感器具有灵敏度高、选择性好、操作简便、快速等优点，适用于环境中汞离子的监测。
Mercuric ion (Hg2+) is one toxic metal ion existed in aquatic ecosystems which would seriously damage human central nervous system and other organs. So developing an approach to sensitively detect Hg2+in our living environment is urgent and important. In this work, a novel surface enhancement Raman spectrum(SERS) sensor is fabricated for high selective and ultrasensitive detection of Hg2+in aqueous solution, based on a stable thymine-Hg2+-thymine (T-Hg2+-T) structure and theπ-πinteraction between single-stranded DNA (ssDNA) and single walled carbon nanotubes (SWCNTs). Herein, SWCNTs act as Raman labels to produce characteristic Raman peaks which can be a beacon to quantitative detect Hg2+. In the presence of Hg2+, the ssDNA can capture Hg2+forming T-Hg2+-T structure, which makes SWCNTs leave the hot spots of the SERS-based biosensor. With this design, the Raman intensity of SWCNTs decreased with the increasing concentration of Hg2+. At the same time, CoFe2O4@Ag as active SERS substrates can effectively enhance sensitivity and uniformity of the biosensor through aggregation by magnet. Under optimal conditions, this proposed biosensor can detect Hg2+at a range from 1 pM to 100 nM with a detection limit of 0.84 pM. With the advantages of good sensitivity, selectivity, simplicity and rapidity, the biosensor is potentially suitable for monitoring of Hg2+in environmental applications.