中文摘要：

以DNA杂交双链为联接,构建纳米金颗粒Core-satellites结构并激发等离子体耦合增强效应,利用Hg2＋可与DNA中胸腺嘧啶T形成T-Hg2＋-T特异性结构,研制了用于检测水中Hg2＋的局域等离子体共振（LSPR）光纤传感器。待测溶液中的Hg2＋能够引起富含T的DNA单链折叠,抑制DNA杂交反应,降低等离子体耦合强度,改变LSPR谐振波长。通过检测谐振波长红移变化,实现对Hg2＋浓度的定量检测。本方法检测Hg2＋的线性范围为5-150 nmol/L,检出限为3.4 nmol/L（3σ）。Zn2＋、Mg2＋、Pb2＋等重金属离子对Hg2＋检测无明显干扰作用。实际水样中Hg2＋加样回收率为94.2%-105.4%,相对标准偏差〈4.8%。

英文摘要：

Based on the plasmon coupling effect in gold nanoparticles core-satellite nanostructures linked by thymine （ T） -rich DNA hybridization and the specific Hg2＋-mediated T-Hg2＋-T base pair, a novel localized surface plasmon resonance （ LSPR） optical fiber sensor was proposed and developed for Hg2＋ detection in water. The Hg2＋-induced conformational change in T-rich DNA sequence inhibited the DNA hybridization reaction,weakened the plasmon coupling effect and leaded to the change of LSPR resonance wavelength. The concentration of Hg2＋ was quantitatively determined by the resonance wavelength redshift. The linear range of Hg2＋ detection was about 5-150 nmol/L with LOD about 3. 4 nmol/L. The specificity of the sensor was proved great by evaluating the response to other heavy metal ions such as Zn2＋, Mg2＋, Pb2＋ and so on. This sensor was applied in environmental water detection by standard addition method,with the RSD less than 4.8% and recoveries of 94. 2% -105. 4% .