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Monitoring the presence of ionic mercury in environmental water by plasmon-enhanced infrared spectroscopy.

Hoang CV, Oyama M, Saito O, Aono M, Nagao T - Sci Rep (2013)

Bottom Line: Here, we adopted single-stranded thiolated 15-base DNA oligonucleotides that are immobilized on the Au surface and show strong specificity to Hg²⁺.The mercury-associated distinct signal is located apart from the biomolecule-associated broad signals and is selectively characterized.For example, with natural water from Lake Kasumigaura (Ibaraki Prefecture, Japan), direct detection of Hg²⁺ with a concentration as low as 37 ppt (37 × 10⁻¹⁰%) was readily demonstrated, indicating the high potential of this simple method for environmental and chemical sensing of metallic species in aqueous solution.

View Article: PubMed Central - PubMed

Affiliation: WPI Center for Materials NanoArchitectonics-MANA, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan. Hoang.ChungVu@nims.go.jp

ABSTRACT
We demonstrate the ppt-level single-step selective monitoring of the presence of mercury ions (Hg²⁺) dissolved in environmental water by plasmon-enhanced vibrational spectroscopy. We combined a nanogap-optimized mid-infrared plasmonic structure with mercury-binding DNA aptamers to monitor in-situ the spectral evolution of the vibrational signal of the DNA induced by the mercury binding. Here, we adopted single-stranded thiolated 15-base DNA oligonucleotides that are immobilized on the Au surface and show strong specificity to Hg²⁺. The mercury-associated distinct signal is located apart from the biomolecule-associated broad signals and is selectively characterized. For example, with natural water from Lake Kasumigaura (Ibaraki Prefecture, Japan), direct detection of Hg²⁺ with a concentration as low as 37 ppt (37 × 10⁻¹⁰%) was readily demonstrated, indicating the high potential of this simple method for environmental and chemical sensing of metallic species in aqueous solution.

No MeSH data available.


Detection of the presence of ionic mercury in environmental water.Spectral evolution shown as a function of Hg2+ concentration (added into water of Lake Kasumigaura). DNA-related signal is indicated by red peak and small red arrows. Green absorption feature shows the residual biomolecules in the lake water. Note that the scale of reflectance is different for each sub-graph.
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f4: Detection of the presence of ionic mercury in environmental water.Spectral evolution shown as a function of Hg2+ concentration (added into water of Lake Kasumigaura). DNA-related signal is indicated by red peak and small red arrows. Green absorption feature shows the residual biomolecules in the lake water. Note that the scale of reflectance is different for each sub-graph.

Mentions: Figure 4 shows the evolution of relative IR spectra taken from the natural lake water mixed with different Hg2+ concentrations. The reference spectrum was taken from the original lake water before mixing with a trace amount of Hg2+. Each spectrum was accumulated for 30 min to ensure the near saturation of the mercury adsorption. In contrast to the spectrum of the original natural lake water without Hg2+ (Fig. 3(c)), we clearly observed the evolution of the peak at ωT = 1400 cm−1 (marked as red, solid line), which systematically changed its intensity depending on the Hg2+ concentration. The peak shape remains unchanged with different concentrations. Also no shift in the peak position was observed. This intensity change was not observable from the water without Hg2+ and only observed from the Hg containing solutions. Also we did not observe the changes in C = O and C = C bands at ω = 1656 cm−1 and 1724 cm−1 indicating that the DNA itself did not desorb from the surface.


Monitoring the presence of ionic mercury in environmental water by plasmon-enhanced infrared spectroscopy.

Hoang CV, Oyama M, Saito O, Aono M, Nagao T - Sci Rep (2013)

Detection of the presence of ionic mercury in environmental water.Spectral evolution shown as a function of Hg2+ concentration (added into water of Lake Kasumigaura). DNA-related signal is indicated by red peak and small red arrows. Green absorption feature shows the residual biomolecules in the lake water. Note that the scale of reflectance is different for each sub-graph.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3569543&req=5

f4: Detection of the presence of ionic mercury in environmental water.Spectral evolution shown as a function of Hg2+ concentration (added into water of Lake Kasumigaura). DNA-related signal is indicated by red peak and small red arrows. Green absorption feature shows the residual biomolecules in the lake water. Note that the scale of reflectance is different for each sub-graph.
Mentions: Figure 4 shows the evolution of relative IR spectra taken from the natural lake water mixed with different Hg2+ concentrations. The reference spectrum was taken from the original lake water before mixing with a trace amount of Hg2+. Each spectrum was accumulated for 30 min to ensure the near saturation of the mercury adsorption. In contrast to the spectrum of the original natural lake water without Hg2+ (Fig. 3(c)), we clearly observed the evolution of the peak at ωT = 1400 cm−1 (marked as red, solid line), which systematically changed its intensity depending on the Hg2+ concentration. The peak shape remains unchanged with different concentrations. Also no shift in the peak position was observed. This intensity change was not observable from the water without Hg2+ and only observed from the Hg containing solutions. Also we did not observe the changes in C = O and C = C bands at ω = 1656 cm−1 and 1724 cm−1 indicating that the DNA itself did not desorb from the surface.

Bottom Line: Here, we adopted single-stranded thiolated 15-base DNA oligonucleotides that are immobilized on the Au surface and show strong specificity to Hg²⁺.The mercury-associated distinct signal is located apart from the biomolecule-associated broad signals and is selectively characterized.For example, with natural water from Lake Kasumigaura (Ibaraki Prefecture, Japan), direct detection of Hg²⁺ with a concentration as low as 37 ppt (37 × 10⁻¹⁰%) was readily demonstrated, indicating the high potential of this simple method for environmental and chemical sensing of metallic species in aqueous solution.

View Article: PubMed Central - PubMed

Affiliation: WPI Center for Materials NanoArchitectonics-MANA, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan. Hoang.ChungVu@nims.go.jp

ABSTRACT
We demonstrate the ppt-level single-step selective monitoring of the presence of mercury ions (Hg²⁺) dissolved in environmental water by plasmon-enhanced vibrational spectroscopy. We combined a nanogap-optimized mid-infrared plasmonic structure with mercury-binding DNA aptamers to monitor in-situ the spectral evolution of the vibrational signal of the DNA induced by the mercury binding. Here, we adopted single-stranded thiolated 15-base DNA oligonucleotides that are immobilized on the Au surface and show strong specificity to Hg²⁺. The mercury-associated distinct signal is located apart from the biomolecule-associated broad signals and is selectively characterized. For example, with natural water from Lake Kasumigaura (Ibaraki Prefecture, Japan), direct detection of Hg²⁺ with a concentration as low as 37 ppt (37 × 10⁻¹⁰%) was readily demonstrated, indicating the high potential of this simple method for environmental and chemical sensing of metallic species in aqueous solution.

No MeSH data available.