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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: 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 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.


Time-dependent UV-vis spectra showing the reduction of silver ions with PEG 400.
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Fig4: Time-dependent UV-vis spectra showing the reduction of silver ions with PEG 400.

Mentions: To confirm that PEG 400 is able to act as a reducing agent, 1 M AgNO3 solution was mixed with pure PEG 400 (volume ratio 1:1). The reaction was monitored in real time by using UV-vis spectroscopy (Figure 4). At the beginning of the reaction, no absorption peak characteristic for silver nanoparticles was recorded. Nevertheless, a broad plasmon occurred in the spectra after 20 min from the moment when the silver precursor and the polymer were mixed. The plasmon increased with increasing the reaction time and was found to be located at 428 nm. The peak reached the maximum after 50 min and did not rise with longer reaction time, which indicated the end of the reaction. The colour of the solution changed from colourless to yellow which also suggested the successful synthesis of silver nanoparticles.Figure 4


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)

Time-dependent UV-vis spectra showing the reduction of silver ions with PEG 400.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig4: Time-dependent UV-vis spectra showing the reduction of silver ions with PEG 400.
Mentions: To confirm that PEG 400 is able to act as a reducing agent, 1 M AgNO3 solution was mixed with pure PEG 400 (volume ratio 1:1). The reaction was monitored in real time by using UV-vis spectroscopy (Figure 4). At the beginning of the reaction, no absorption peak characteristic for silver nanoparticles was recorded. Nevertheless, a broad plasmon occurred in the spectra after 20 min from the moment when the silver precursor and the polymer were mixed. The plasmon increased with increasing the reaction time and was found to be located at 428 nm. The peak reached the maximum after 50 min and did not rise with longer reaction time, which indicated the end of the reaction. The colour of the solution changed from colourless to yellow which also suggested the successful synthesis of silver nanoparticles.Figure 4

Bottom Line: 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 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.