Aptamer-modified AuRe Nanoalloy Probe for Trace Hg2+ Using Resonance Scattering as Detection Technique

✍ Scribed by Zhiliang Jiang; Jing Zhang; Guiqing Wen; Aihui Liang; Qingye Liu; Caiyan Kang; Xingcun He

• Book ID: 102103941
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 95 KB
• Volume: 28
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.201090201

✦ Synopsis

The AuRe nanoalloy particles in molar ratio of 9∶1 were prepared by sodium borohydride procedure, and modified by single strand DNA (ssDNA) to prepare an aptamer AuRe nanoprobe (AuRessDNA) for Hg 2＋ . In the pH 7.0 Na 2 HPO 4 -NaH 2 PO 4 buffer solution and in the presence of NaCl, Hg 2＋ interacted with AuRessDNA to form double-stranded T-Hg 2＋ -T mismatched and release AuRe nanoparticles that aggregate to large AuRe nanoparticles clusters causing the resonance scattering (RS) peak red shifting and the RS intensity enhanced linearly. On those grounds, 0.067-33.3 nmol•L -1 Hg 2＋ can be detected rapidly by the aptamer-modified AuRe nanoparticles RS assay, with a detection limit of 0.04 nmol•L -1 Hg 2＋ . If the aggregated AuRe particles were removed by membrane filtration, the excess AuRessDNA in the filtration solution exhibits catalytic effect on the new Te particle reaction between Na 2 TeO 4 and SnCl 2 . As the concentration of Hg 2＋ increased, the AuRessDNA nanoparticles in the filtrate solution decreased, the RS intensity at 734 nm decreased linearly. The Hg 2＋ concentration (c) in the range of 0.00133-0.267 nmol•L -1 was linear to the decreased RS intensity (∆I 734nm ), with a regression equation of ∆I＝ -786.4c-4.4, a correlation coefficient of 0.9975, and a detection limit of 0.9 pmol•L -1 Hg 2＋ . This method was applied to the detection of Hg 2＋ in water samples, with satisfactory results.