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The synthesis of controlled shape nanoplasmonic silver-silica structures by combining sol-gel technique and direct silver reduction.

Ramanauskaite L, Snitka V - Nanoscale Res Lett (2015)

Bottom Line: The key point of the work was the usage of polyethylene glycol 400 (PEG 400) both as the pore former and reducing agent for silver ions.The results of UV-vis absorbance spectra have shown the high quality of plasmonic structures with plasmon resonance wavelength in the region between 470 and 480 nm.The synthesized silica films decorated with silver nanoparticles were tested as substrates for the surface-enhanced Raman spectroscopy (SERS) and showed an enhancement relative to micro-Raman of more than 200 times.

View Article: PubMed Central - PubMed

Affiliation: Research Center for Microsystems and Nanotechnology, Kaunas University of Technology, Studentu 65, LT-51369 Kaunas, Lithuania.

ABSTRACT
In this work, we have obtained nanoplasmonic silver structures deposited on the glass substrates by combining sol-gel technology and direct silver ion reduction on the film surfaces. The key point of the work was the usage of polyethylene glycol 400 (PEG 400) both as the pore former and reducing agent for silver ions. We have investigated the influence of PEG 400 amount on the formation of silver nanoparticles on the film surface. It was found that control of PEG 400 amount in the sols allows the creation of porous films with specific organized silver nanoparticles or clusters on the surface. Optical, morphological and structural characteristics of the structures were measured and studied. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used for nanostructure size and shape characterization. We were able to form a 40- to 200-nm-diameter ring-type, spherical and self-assembled nanoparticles on the film surface. The results of UV-vis absorbance spectra have shown the high quality of plasmonic structures with plasmon resonance wavelength in the region between 470 and 480 nm. The synthesized silica films decorated with silver nanoparticles were tested as substrates for the surface-enhanced Raman spectroscopy (SERS) and showed an enhancement relative to micro-Raman of more than 200 times.

No MeSH data available.


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Illustration of the synthesis of the hybrid silica films.
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Fig1: Illustration of the synthesis of the hybrid silica films.

Mentions: The sol was prepared by mixing TEOS, ethanol and water in the flask with ratios 0.2:0.4:1, respectively. Reaction was carried out under the acidic conditions: hydrochloric acid was used to reach the pH value of 2.3. The solution was mixed for 1 h maintaining a constant temperature of 60°C and finally divided into three flasks. Pure PEG 400 was added to reach sol/PEG ratios of 1:0.05 (v:v), 1:0.10 (v:v) and 1:0.15 (v:v) in each flask, respectively. All PEG 400-modified sols were aged for 48 h at room temperature. The films were formed on the ethanol-cleaned microscopic glasses by spin-coating method with a spin speed of 1,500 rpm and a spin time of 10 s, dried at room temperature and heated in air at 300°C for 2 h. After the thermal treatment, all the films were cooled to room temperature, immersed into freshly prepared 1 M AgNO3 solution for 17 h, then removed from the solution and dried under the nitrogen flow. Schematic illustration of the synthesis is represented in Figure 1.Figure 1


The synthesis of controlled shape nanoplasmonic silver-silica structures by combining sol-gel technique and direct silver reduction.

Ramanauskaite L, Snitka V - Nanoscale Res Lett (2015)

Illustration of the synthesis of the hybrid silica films.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385275&req=5

Fig1: Illustration of the synthesis of the hybrid silica films.
Mentions: The sol was prepared by mixing TEOS, ethanol and water in the flask with ratios 0.2:0.4:1, respectively. Reaction was carried out under the acidic conditions: hydrochloric acid was used to reach the pH value of 2.3. The solution was mixed for 1 h maintaining a constant temperature of 60°C and finally divided into three flasks. Pure PEG 400 was added to reach sol/PEG ratios of 1:0.05 (v:v), 1:0.10 (v:v) and 1:0.15 (v:v) in each flask, respectively. All PEG 400-modified sols were aged for 48 h at room temperature. The films were formed on the ethanol-cleaned microscopic glasses by spin-coating method with a spin speed of 1,500 rpm and a spin time of 10 s, dried at room temperature and heated in air at 300°C for 2 h. After the thermal treatment, all the films were cooled to room temperature, immersed into freshly prepared 1 M AgNO3 solution for 17 h, then removed from the solution and dried under the nitrogen flow. Schematic illustration of the synthesis is represented in Figure 1.Figure 1

Bottom Line: The key point of the work was the usage of polyethylene glycol 400 (PEG 400) both as the pore former and reducing agent for silver ions.The results of UV-vis absorbance spectra have shown the high quality of plasmonic structures with plasmon resonance wavelength in the region between 470 and 480 nm.The synthesized silica films decorated with silver nanoparticles were tested as substrates for the surface-enhanced Raman spectroscopy (SERS) and showed an enhancement relative to micro-Raman of more than 200 times.

View Article: PubMed Central - PubMed

Affiliation: Research Center for Microsystems and Nanotechnology, Kaunas University of Technology, Studentu 65, LT-51369 Kaunas, Lithuania.

ABSTRACT
In this work, we have obtained nanoplasmonic silver structures deposited on the glass substrates by combining sol-gel technology and direct silver ion reduction on the film surfaces. The key point of the work was the usage of polyethylene glycol 400 (PEG 400) both as the pore former and reducing agent for silver ions. We have investigated the influence of PEG 400 amount on the formation of silver nanoparticles on the film surface. It was found that control of PEG 400 amount in the sols allows the creation of porous films with specific organized silver nanoparticles or clusters on the surface. Optical, morphological and structural characteristics of the structures were measured and studied. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used for nanostructure size and shape characterization. We were able to form a 40- to 200-nm-diameter ring-type, spherical and self-assembled nanoparticles on the film surface. The results of UV-vis absorbance spectra have shown the high quality of plasmonic structures with plasmon resonance wavelength in the region between 470 and 480 nm. The synthesized silica films decorated with silver nanoparticles were tested as substrates for the surface-enhanced Raman spectroscopy (SERS) and showed an enhancement relative to micro-Raman of more than 200 times.

No MeSH data available.


Related in: MedlinePlus