In this paper ,a detection of trace Hg (Ⅱ ) was based on silver nanorods by surface-enhanced Raman spectroscopy (SERS)activity .It was discussed the probe types ,which explored that the L-cysteine with a high selectivity and sensitivity for Hg(Ⅱ) .The UV/Vis spectra was used to characterize the silver nanorods and its modified the L-Cys .Based on L-cysteine of SERS was high sensitivity and selectivity for Hg(Ⅱ) on condition that the ten kinds of metal ions carried on ,but only when the single-peak at 1040 cm-1 structure appeared after adding the Hg(Ⅱ) .SERS sensor with L-cysteine assembled silver nanorods firmly captured the Hg(Ⅱ) through the S-Hg bond .It was valuable to get the molecular probe of the concentration ,pH and temperature ,in which the result showed the optimization when the density of L-cysteine was 1 × 10-3 mol · L -1 and pH was 7 . It did not have a great effect on temperatures ,but was down trend over 55 ℃ .In order to protect the structure of L-Cysteine and form complexes rapidly ,it was selected temperature about 45 ℃ .Under the optimized conditions ,a series of the concentration of mercury ions were measured ,in which the result showed that the density of mercury ions between 0.01 and 5 μmol · L -1 can be analyzed because of a strong peak at 1040 cm-1 with good linear relationships (correlation=0.990) with the detection limit of 1 nmol · L -1 .Which had very excellent sensitivity and stability .When Hg2+ was tested in real water samples ,the recovery was from 85% ~103% .It establishes a good way to determine the trace Hg(Ⅱ) .%以L-半胱氨酸(L-Cys)组装银纳米棒的SERS传感器检测汞离子.讨论了能捕获汞离子的标记分子的种类,选择L-Cys为标记分子,L-Cys通过S—Ag键链接在银纳米棒表面.紫外-可见吸收光谱对银纳米棒及组装上L-Cys和Hg2+分别进行表征,通过10种金属离子验证了该分子探针的对汞离子的特异性吸附,构建了"Ag-L-Cys-Hg"层状结构.标记分子-金属纳米粒子偶联物的稳定性由配体分子、温度、pH值等决定,讨论了L-Cys标记分子的浓度、pH值、温度的最佳条件,对一系列汞离子浓度进行测定,线性范围在0.01~1μmol·L-1之间,相关系数为0.990,检出限为1 nmol·L-1.对实际水样进行了测定,加标回收率在85%~103%之间.建立了一种高效、快捷、灵敏度高、稳定性好痕量测定Hg2+的方法.
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