Resonance Scattering Spectral Detection of Trace Hg2+ Using Aptamer-Modified Nanogold as Probe and Nanocatalyst

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• 作者：Zhiliang Jiang ; Yanyan Fan ; Menglin Chen ; Aihui Liang ; Xianjiu Liao ; Guiqing Wen ; Xingcan Shen ; Xingcun He ; Hongchen Pan ; Hesheng Jiang
• 刊名：Analytical Chemistry
• 出版年：2009
• 出版时间：July 1, 2009
• 年：2009
• 卷：81
• 期：13
• 页码：5439-5445
• 全文大小：317K
• 年卷期：v.81,no.13(July 1, 2009)
• ISSN：1520-6882

文摘

Single-strand DNA (ssDNA) was used to modify 10 nm nanogold to obtain an aptamer-modified nanogold resonance scattering (RS) probe (AussDNA) for detection of Hg²⁺. In the presence of NaCl, Hg²⁺ interacts with AussDNA to form very stable double-strand T−Hg²⁺−T mismatches and release nanogold particles that aggregate to large nanogold clusters causing the RS intensity at 540 nm to be enhanced linearly. On those grounds, 1.3−1667 nM Hg²⁺ can be detected rapidly by the aptamer-modified nanogold RS assay, with a detection limit of 0.7 nM Hg²⁺. If the large nanogold clusters were removed by membrane filtration, the excess AussDNA in the filtrate solution exhibits a catalytic effect on the new Cu₂O particle reaction between NH₂OH and Cu²⁺−EDTA complex at 60 °C. The excess AussDNA decreased with the addition of Hg²⁺, which led the Cu₂O particle RS intensity at 602 nm to decrease. The decreased RS intensity (ΔI_602nm) had a linear response to Hg²⁺ concentration in the range of 0.1−400 nM, with a detection limit of 0.03 nM Hg²⁺. This aptamer-modified nanogold catalytic RS method was applied for the detection of Hg²⁺ in water samples, with sensitivity, selectivity, and simplicity.