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Fabrication and evolution of multilayer silver nanofilms for surface-enhanced Raman scattering sensing of arsenate.

Hao J, Han MJ, Xu Z, Li J, Meng X - Nanoscale Res Lett (2011)

Bottom Line: The SERS spectra of arsenate showed that characteristic SERS bands of arsenate appear at approximately 780 and 420 cm-1, and the former possesses higher SERS intensity.By comparing the peak heights of the approximately 780 cm-1 band of the SERS spectra, the optimal Ag/GL substrate has been obtained for the most sensitive SERS sensing of arsenate.Using this optimal substrate, the limit of detection (LOD) of arsenate was determined to be approximately 5 μg·l-1.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030, USA. xmeng@stevens.edu.

ABSTRACT
Surface-enhanced Raman scattering (SERS) has recently been investigated extensively for chemical and biomolecular sensing. Multilayer silver (Ag) nanofilms deposited on glass slides by a simple electroless deposition process have been fabricated as active substrates (Ag/GL substrates) for arsenate SERS sensing. The nanostructures and layer characteristics of the multilayer Ag films could be tuned by varying the concentrations of reactants (AgNO3/BuNH2) and reaction time. A Ag nanoparticles (AgNPs) double-layer was formed by directly reducing Ag+ ions on the glass surfaces, while a top layer (3rd-layer) of Ag dendrites was deposited on the double-layer by self-assembling AgNPs or AgNPs aggregates which had already formed in the suspension. The SERS spectra of arsenate showed that characteristic SERS bands of arsenate appear at approximately 780 and 420 cm-1, and the former possesses higher SERS intensity. By comparing the peak heights of the approximately 780 cm-1 band of the SERS spectra, the optimal Ag/GL substrate has been obtained for the most sensitive SERS sensing of arsenate. Using this optimal substrate, the limit of detection (LOD) of arsenate was determined to be approximately 5 μg·l-1.

No MeSH data available.


Related in: MedlinePlus

SERS spectra of arsenate at the different concentrations using Ag/GL-5/2.5-18 as an active substrate: (a) 0, (b) 5, (c) 25, (d) 75, and (e) 150 μg·L-1. The spectra were shifted vertically for clarity but the relative intensity was kept unchanged.
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Figure 7: SERS spectra of arsenate at the different concentrations using Ag/GL-5/2.5-18 as an active substrate: (a) 0, (b) 5, (c) 25, (d) 75, and (e) 150 μg·L-1. The spectra were shifted vertically for clarity but the relative intensity was kept unchanged.

Mentions: The SERS spectra of arsenate on every optimized substrate were measured in the concentration range 0-200 μg·l-1. Figure 7 shows the SERS spectra as a function of arsenate concentration recorded on Ag/GL-5/2.5-18 substrate. It is clear that a steady decrease in SERS intensity or peak height of the arsenate Raman band is observed with decreasing arsenate concentration. When the concentration is lower than 5 μg·l-1, the arsenate SERS band at approximately 780 cm-1 appeared to be a shoulder of the 815 cm-1 band, which is not easily discerned. Therefore, the LOD of Ag/GL-5/2.5-18 substrate for arsenate was determined to be approximately 5 μg·l-1. SERS sensing of low concentration arsenate may suffer from the interference of the 815 cm-1 background Raman band. LODs of Ag/GL-1/0.5-25 substrate and Ag/GL-10/5-6 substrate were also determined, and the relatively high values are obtained, i.e., approximately 50 and 20 μg·l-1, respectively.


Fabrication and evolution of multilayer silver nanofilms for surface-enhanced Raman scattering sensing of arsenate.

Hao J, Han MJ, Xu Z, Li J, Meng X - Nanoscale Res Lett (2011)

SERS spectra of arsenate at the different concentrations using Ag/GL-5/2.5-18 as an active substrate: (a) 0, (b) 5, (c) 25, (d) 75, and (e) 150 μg·L-1. The spectra were shifted vertically for clarity but the relative intensity was kept unchanged.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211326&req=5

Figure 7: SERS spectra of arsenate at the different concentrations using Ag/GL-5/2.5-18 as an active substrate: (a) 0, (b) 5, (c) 25, (d) 75, and (e) 150 μg·L-1. The spectra were shifted vertically for clarity but the relative intensity was kept unchanged.
Mentions: The SERS spectra of arsenate on every optimized substrate were measured in the concentration range 0-200 μg·l-1. Figure 7 shows the SERS spectra as a function of arsenate concentration recorded on Ag/GL-5/2.5-18 substrate. It is clear that a steady decrease in SERS intensity or peak height of the arsenate Raman band is observed with decreasing arsenate concentration. When the concentration is lower than 5 μg·l-1, the arsenate SERS band at approximately 780 cm-1 appeared to be a shoulder of the 815 cm-1 band, which is not easily discerned. Therefore, the LOD of Ag/GL-5/2.5-18 substrate for arsenate was determined to be approximately 5 μg·l-1. SERS sensing of low concentration arsenate may suffer from the interference of the 815 cm-1 background Raman band. LODs of Ag/GL-1/0.5-25 substrate and Ag/GL-10/5-6 substrate were also determined, and the relatively high values are obtained, i.e., approximately 50 and 20 μg·l-1, respectively.

Bottom Line: The SERS spectra of arsenate showed that characteristic SERS bands of arsenate appear at approximately 780 and 420 cm-1, and the former possesses higher SERS intensity.By comparing the peak heights of the approximately 780 cm-1 band of the SERS spectra, the optimal Ag/GL substrate has been obtained for the most sensitive SERS sensing of arsenate.Using this optimal substrate, the limit of detection (LOD) of arsenate was determined to be approximately 5 μg·l-1.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030, USA. xmeng@stevens.edu.

ABSTRACT
Surface-enhanced Raman scattering (SERS) has recently been investigated extensively for chemical and biomolecular sensing. Multilayer silver (Ag) nanofilms deposited on glass slides by a simple electroless deposition process have been fabricated as active substrates (Ag/GL substrates) for arsenate SERS sensing. The nanostructures and layer characteristics of the multilayer Ag films could be tuned by varying the concentrations of reactants (AgNO3/BuNH2) and reaction time. A Ag nanoparticles (AgNPs) double-layer was formed by directly reducing Ag+ ions on the glass surfaces, while a top layer (3rd-layer) of Ag dendrites was deposited on the double-layer by self-assembling AgNPs or AgNPs aggregates which had already formed in the suspension. The SERS spectra of arsenate showed that characteristic SERS bands of arsenate appear at approximately 780 and 420 cm-1, and the former possesses higher SERS intensity. By comparing the peak heights of the approximately 780 cm-1 band of the SERS spectra, the optimal Ag/GL substrate has been obtained for the most sensitive SERS sensing of arsenate. Using this optimal substrate, the limit of detection (LOD) of arsenate was determined to be approximately 5 μg·l-1.

No MeSH data available.


Related in: MedlinePlus