摘要
汞离子(Hg2+)的暴露对人体健康构成了严重的威胁,目前对痕量Hg2+检测提出了较高的要求.本研究合成一种Au-DNA成膜基底,基于T-Hg2+-T理论,利用表面增强拉曼散射技术,以达到检测水体中痕量Hg2+的目的.Au纳米结构通过DNA适配体功能化,在Hg2+存在下,DNA适配体形成发夹结构,使其末端的Cy5与Hg2+特异性结合后靠近Au热点区域,从而产生增强的拉曼信号.Au-DNA成膜条件优化的结果表明,Au浓度为3×10-3 mol·L-1,成膜剂Nafion为0.0004%时,具有强度最高的拉曼信号.此方法合成的Au-DNA成膜基底,检测下限为1×10-12 mol·L-1,与之前报道相比具有更高的灵敏性,可以达到国家饮用水标准.该基底对Hg2+的检测具有特异性,不受共存离子和环境基质的干扰,且展现出良好的稳定性,当基底浸入水体1 h后,仍具有较高的灵敏度.Au-DNA成膜基底作为表面增强拉曼散射平台具有较高的灵敏性、选择性、稳定性与可回收性,是一种很有前途的Hg2+现场快速检测手段.
The exposure of mercury ions(Hg2+)poses a serious threat to human health,therefore,high requirements are promoted for the detection of trace Hg2+.In this study,an Au-DNA film-forming substrate was synthesized.Based on the T-Hg2+-T protocol,surface enhanced Raman scattering(SERS)technique was used to detect the trace amount of Hg2+in water.The Au nanostructure was functionalized by a DNA aptamer.In the presence of Hg2+,the DNA aptamer formed a hairpin structure,bringing Cy5 at the end of the DNA aptamer specifically bind to Hg2+and then close to the Au hotspots region,thereby generating an enhanced Raman signal intensity.The results of Au-DNA film formation process suggested that under conditions of the concentration of Au 3×10-3 mol·L-1 and the film former Nafion 0.0004%,the SERS signal with the highest intensity was obtained.The Au-DNA film-forming substrate synthesized inhere had a detection limit of 1×10-12 mol·L-1,which was more sensitive than the previous report and could meet the national drinking water standard.The substrate was desirable for the detection of Hg2+and the influence of other metal ions could be negligible.The as-prepared substrate showed good stability and sensitivity even immersed in water for 1 h.With the high sensitivity,selectivity,stability,and recyclability,this Au-DNA SERS platform provides a promising tool for field monitoring of Hg2+ions.
作者
胡舒馨
张建锋
HU Shuxin;ZHANG Jianfeng(Shaanxi Key Laboratory of Environmental Engineering,Xi'an University of Architecture and Technology,Xi'an,710055,China;School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an,710055,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第9期2459-2468,共10页
Environmental Chemistry
基金
国家重点研发计划项目(2017YFC0403403-3/01)资助
作者简介
通讯联系人:张建锋,Tel:13572539766,E-mail:zhangjianfeng@xauat.edu.cn
