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Preparation of plasmonic platforms of silver wires on gold mirrors and their application to surface enhanced fluorescence.

Shtoyko T, Raut S, Rich RM, Sronce RJ, Fudala R, Mason RN, Akopova I, Gryczynski Z, Gryczynski I - ACS Appl Mater Interfaces (2014)

Bottom Line: Silica protected gold mirrors were drop-coated with a solution of silver triangular nanoprisms.The triangular nanoprisms were slowly air-dried to get silver wires that self-assembled on the gold mirrors.The lifetime of Me-ADOTA · Cl dye was significantly reduced (∼ 4 times) in the presence of SWs.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, The University of Texas at Tyler , 3900 University Boulevard, Tyler, Texas 75799, United States.

ABSTRACT
In this report we describe a preparation of silver wires (SWs) on gold mirrors and its application to surface enhanced fluorescence (SEF) using a new methodology. Silica protected gold mirrors were drop-coated with a solution of silver triangular nanoprisms. The triangular nanoprisms were slowly air-dried to get silver wires that self-assembled on the gold mirrors. Fluorescence enhancement was studied using methyl azadioxatriangulenium chloride (Me-ADOTA · Cl) dye in PVA spin-coated on a clean glass coverslip. New Plasmonic Platforms (PPs) were assembled by placing a mirror with SWs in contact with a glass coverslip spin-coated with a uniform Me-ADOTA · Cl film. It was shown that surface enhanced fluorescence is a real phenomenon, not just an enhancement of the fluorescence signal due to an accumulation of the fluorophore on rough nanostructure surfaces. The average fluorescence enhancement was found to be about 15-fold. The lifetime of Me-ADOTA · Cl dye was significantly reduced (∼ 4 times) in the presence of SWs. Moreover, fluorescence enhancement and lifetime did not show any dependence on the excitation light polarization.

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(A) SEM photomicrographof silver wires on silica protected gold mirror. (B) AFM image (100μm × 110 μm) of silver wires on silica protectedgold mirror. (C) Height profile of SWs on silica protected gold mirrorfor the line drawn in panel B. (D) Absorption spectrum of SW on silicaprotected gold mirror.
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fig2: (A) SEM photomicrographof silver wires on silica protected gold mirror. (B) AFM image (100μm × 110 μm) of silver wires on silica protectedgold mirror. (C) Height profile of SWs on silica protected gold mirrorfor the line drawn in panel B. (D) Absorption spectrum of SW on silicaprotected gold mirror.

Mentions: Freshly synthesized silver nanoprisms wereprepared with a lateral dimension of 40 ± 5 nm and a thicknessof 8.5 ± 1.4 nm.44Supporting Information shows the AFM image of triangular nanoprisms.The solution of silver triangular nanoprisms was drop coated ontothe slide. It was discovered that silver nanoprisms self-assembleddifferently on dissimilar surfaces. The self-assembly also dependson the drying conditions and the drying time. Allowing the solutionof silver nanoprisms to air-dry on a bare gold mirror resulted inindividual nanoprisms deposited on the gold mirror.41 While there was not complete coverage, the self-assembledstructures had a uniform distribution on the slide.41 Here, a silver colloid solution was cast on a 48 nm thickgold mirror surface protected with 5 nm silica and slow dried in anear isolation chamber at room temperature. In this case, silver nanowiresassembled rather than individual nanoprisms as previously seen. TheSEM and AFM images of typical self-assembled SWs on silica protectedgold mirrors are shown in Figures 2A,B, respectively.While there is not complete coverage on the slide, the self-assembledSWs have a uniform distribution. The assembled wires are from 10 to100 μm in width and a few centimeters long. The images werezoomed to see the edges of the protected gold film substrate. The z-dimension of SWs is less than 1 μm high from thesurface of the slide, as shown in Figure 2C.The coverage is also very reproducible. Moreover, it is importantto understand that these structures sustain plasmonic absorption despitethe large dimensions. Figure 2D shows the typicalplasmonic absorption of SW on the silica protected gold film on aglass slide with the absorption maximum at about 500 nm. SW on a plainglass slide shows absorption maximum around 450 nm (data not shown).The red-shifted absorption on the silica protected gold film couldbe due to the plasmonic interaction of SW with gold mirror.


Preparation of plasmonic platforms of silver wires on gold mirrors and their application to surface enhanced fluorescence.

Shtoyko T, Raut S, Rich RM, Sronce RJ, Fudala R, Mason RN, Akopova I, Gryczynski Z, Gryczynski I - ACS Appl Mater Interfaces (2014)

(A) SEM photomicrographof silver wires on silica protected gold mirror. (B) AFM image (100μm × 110 μm) of silver wires on silica protectedgold mirror. (C) Height profile of SWs on silica protected gold mirrorfor the line drawn in panel B. (D) Absorption spectrum of SW on silicaprotected gold mirror.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232249&req=5

fig2: (A) SEM photomicrographof silver wires on silica protected gold mirror. (B) AFM image (100μm × 110 μm) of silver wires on silica protectedgold mirror. (C) Height profile of SWs on silica protected gold mirrorfor the line drawn in panel B. (D) Absorption spectrum of SW on silicaprotected gold mirror.
Mentions: Freshly synthesized silver nanoprisms wereprepared with a lateral dimension of 40 ± 5 nm and a thicknessof 8.5 ± 1.4 nm.44Supporting Information shows the AFM image of triangular nanoprisms.The solution of silver triangular nanoprisms was drop coated ontothe slide. It was discovered that silver nanoprisms self-assembleddifferently on dissimilar surfaces. The self-assembly also dependson the drying conditions and the drying time. Allowing the solutionof silver nanoprisms to air-dry on a bare gold mirror resulted inindividual nanoprisms deposited on the gold mirror.41 While there was not complete coverage, the self-assembledstructures had a uniform distribution on the slide.41 Here, a silver colloid solution was cast on a 48 nm thickgold mirror surface protected with 5 nm silica and slow dried in anear isolation chamber at room temperature. In this case, silver nanowiresassembled rather than individual nanoprisms as previously seen. TheSEM and AFM images of typical self-assembled SWs on silica protectedgold mirrors are shown in Figures 2A,B, respectively.While there is not complete coverage on the slide, the self-assembledSWs have a uniform distribution. The assembled wires are from 10 to100 μm in width and a few centimeters long. The images werezoomed to see the edges of the protected gold film substrate. The z-dimension of SWs is less than 1 μm high from thesurface of the slide, as shown in Figure 2C.The coverage is also very reproducible. Moreover, it is importantto understand that these structures sustain plasmonic absorption despitethe large dimensions. Figure 2D shows the typicalplasmonic absorption of SW on the silica protected gold film on aglass slide with the absorption maximum at about 500 nm. SW on a plainglass slide shows absorption maximum around 450 nm (data not shown).The red-shifted absorption on the silica protected gold film couldbe due to the plasmonic interaction of SW with gold mirror.

Bottom Line: Silica protected gold mirrors were drop-coated with a solution of silver triangular nanoprisms.The triangular nanoprisms were slowly air-dried to get silver wires that self-assembled on the gold mirrors.The lifetime of Me-ADOTA · Cl dye was significantly reduced (∼ 4 times) in the presence of SWs.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, The University of Texas at Tyler , 3900 University Boulevard, Tyler, Texas 75799, United States.

ABSTRACT
In this report we describe a preparation of silver wires (SWs) on gold mirrors and its application to surface enhanced fluorescence (SEF) using a new methodology. Silica protected gold mirrors were drop-coated with a solution of silver triangular nanoprisms. The triangular nanoprisms were slowly air-dried to get silver wires that self-assembled on the gold mirrors. Fluorescence enhancement was studied using methyl azadioxatriangulenium chloride (Me-ADOTA · Cl) dye in PVA spin-coated on a clean glass coverslip. New Plasmonic Platforms (PPs) were assembled by placing a mirror with SWs in contact with a glass coverslip spin-coated with a uniform Me-ADOTA · Cl film. It was shown that surface enhanced fluorescence is a real phenomenon, not just an enhancement of the fluorescence signal due to an accumulation of the fluorophore on rough nanostructure surfaces. The average fluorescence enhancement was found to be about 15-fold. The lifetime of Me-ADOTA · Cl dye was significantly reduced (∼ 4 times) in the presence of SWs. Moreover, fluorescence enhancement and lifetime did not show any dependence on the excitation light polarization.

Show MeSH
Related in: MedlinePlus