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Geddes, Chris D.; Lakowicz, Joseph R.

doi:10.1023/a:1016875709579

Cited by 832 publications

(551 citation statements)

References 16 publications

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“…Silver nanostructures, used in recent studies for metal-enhanced fluorescence, 13,14,[17][18][19][20][21][22][23][24][25][26]29,34 show blinking that is dependent on both the type of structure studied and irradiance of the illumination source. We typically observed that silver fractal-like structures could readily be made luminescent with irradiances of 30 W/cm 2 or more, as compared to silver island films, which required at least a 3-5-fold increase, >100 W/cm 2 .…”

Section: Discussionmentioning

confidence: 99%

“…26 We have recently referred to this phenomenon as radiative decay engineering (RDE), 13, 14 , 26 because we were primarily interested in changes in the radiative decay rate, which results in more detectable photons from fluorophores, but occasionally we use the term "metal-enhanced fluorescence" which additionally accounts for another favorable metal-induced effect, namely increased rates of excitation. 17 Here we report the luminescent blinking of the silver nanostructures that we have previously employed in MEF. However, these previous MEF studies were achieved using irradiances significantly smaller than those used to observe the nanostructure luminescence reported here.…”

Section: Introductionmentioning

confidence: 95%

“…In addition to studying their luminescent blinking properties for potential applications as luminescent probes, as markers, and for medical imaging, our primary interest lies in their interactions with organic fluorophores, and how they modify fluorophore spectral properties. The favorable effects produced by close proximity fluorophores to metallic nanostructures includes increased quantum yields and reduced lifetimes, 13,14,17,18 increased fluorophore photostability, 13,14,19,20 enhanced multiphoton excitation, 21,22 and modified rates of energy transfer. [23][24][25] These interactions have been described as due to changes in the photonic mode density, PMD, around the fluorophore,26 and are considered to be through-space as compared to SERS, which is widely thought to be a contact interaction.27 , 28 Such effects are not normally observed in bulk media, where the photonic mode density is not that different from a vacuum, but can be changed by close proximity silver nanostructures.…”

Section: Introductionmentioning

confidence: 99%

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Luminescent Blinking from Silver Nanostructures.

Geddes¹,

Parfenov²,

Gryczyński³

et al. 2003

ChemInform

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Silver nanostructures deposited on glass showed luminescent blinking when excited at a high 442 nm irradiance. The irradiance required to photoactivate the silver, was dependent on the nature of the silver nanostructures. Silver fractal-like structures were found to be highly emissive, requiring only ≈30 W/cm 2 for photoactivation as compared to silver island films and spin-coated silver colloids, which required a significantly higher irradiance, > 100 W/cm 2 , to observe similar luminescent emission. In contrast to our recent findings for gold colloids, foci with different color blinking were also observed, with an increase in luminescence intensity as a function of time. We place these findings in context with recent work from our laboratory which employs these silver nanostructures for applications in metal-enhanced fluorescence, a relatively new phenomenon in fluorescence, whereby metallic particles, colloids, and fractal-like structures can modify the intrinsic radiative decay rate of close proximity fluorescent species. These effects are a consequence of localized changes in photonic mode density around the fluorophores, and we can now report are typically observed at significantly lower illumination intensities as compared to those required to photoactivate silver. Subsequently, our findings strongly suggest that the enhanced fluorescence emission of fluorophores positioned in close proximity to metallic silver structures is not due to either intrinsic silver blinking, or indeed the silver luminescence pumping the fluorophore. Further, the intrinsic luminescence properties of silver reported here, suggest a new class of luminescence probes and labels.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Luminescent Blinking from Silver Nanostructures.

Geddes¹,

Parfenov²,

Gryczyński³

et al. 2003

ChemInform

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, because the sensitivity of FL is still insufficient to meet the needs of some special fields, it is necessary to develop new methods to further enhance the sensitivity of FL detection. Some scientists found that the FL emission of dyes mixed with nano-metal particles could be strongly enhanced (Geddes and Lakowicz 2002), which was caused by surface plasmon resonance between metal nanoparticle and incident light (Aslan 2005). Many nanomaterials, such as gold, copper, silver and zinc, exhibit metal-enhanced fluorescence (MEF) (Ahamed et al 2008).…”

Section: Introductionmentioning

confidence: 99%

The structure, morphology, and the metal-enhanced fluorescence of nano-Ag/ZnO core–shell structure

et al. 2014

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Nano-polycrystalline silver (Ag) particles with the diameter of 60 nm were synthesized by the reducing agent sodium citrate. An amorphous zinc oxide (ZnO) shell layer was then coated on the surface of silver particles using wet chemical method. The Ag/ZnO core-shell structure was characterized by scanning electron microscope, transmission electron microscopy, ultraviolet-visible spectroscopy and fluorescence (FL) measurement. The results showed that nano-Ag/ZnO core-shell particles with an average diameter of *100 nm were prepared successfully, and the FL intensity of Rhodamine 6G (R6G) mixed with Ag/ZnO nanoparticle was 53 % greater than that of the same amount of R6G without any nanoparticles, which may be related to the effect of surface plasmon resonance.

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“…Nanomaterials incorporating semiconductor quantum dots (SQDs), metal nanoparticles (MNPs), metal surfaces, and dye molecules have been studied intensively [1,2,3,4,5,6,7,8,9,10,11,12,13]. Such hybrid structures take advantage of physical properties of different material systems and demonstrate useful sensor and light-harvesting properties.…”

Section: Introductionmentioning

confidence: 99%

Optical properties of coupled metal-semiconductor and metal-molecule nanocrystal complexes: Role of multipole effects

et al. 2008

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We investigate theoretically the effects of interaction between an optical dipole (semiconductor quantum dot or molecule) and metal nanoparticles. The calculated absorption spectra of hybrid structures demonstrate strong effects of interference coming from the exciton-plasmon coupling. In particular, the absorption spectra acquire characteristic asymmetric lineshapes and strong antiresonances. We present here an exact solution of the problem beyond the dipole approximation and find that the multipole treatment of the interaction is crucial for the understanding of stronglyinteracting exciton-plasmon nano-systems. Interestingly, the visibility of the exciton resonance becomes greatly enhanced for small inter-particle distances due to the interference phenomenon, multipole effects, and electromagnetic enhancement. We find that the destructive interference is particularly strong. Using our exact theory, we show that the interference effects can be observed experimentally even in the exciting systems at room temperature.

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Cited by 832 publications

References 16 publications

Luminescent Blinking from Silver Nanostructures.

Luminescent Blinking from Silver Nanostructures.

The structure, morphology, and the metal-enhanced fluorescence of nano-Ag/ZnO core–shell structure

Optical properties of coupled metal-semiconductor and metal-molecule nanocrystal complexes: Role of multipole effects

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