Metal-enhanced excimer (P-type) fluorescence

Zhang, Yongxia; Aslan, Kadir; Previte, Michael J. R.; Geddes, Chris D.

doi:10.1016/j.cplett.2008.04.083

Cited by 17 publications

(7 citation statements)

References 19 publications

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“…Values are reported as both amplitude weighted and mean lifetimes, calculated using Equations 2 and 4 respectively. 40 For these equations t is time, τ i are the lifetime component values, α i are the amplitudes for each component and Σ i α i = 1.…”

Section: 0 Materials and Methodsmentioning

confidence: 99%

Heavy carbon nanodots: a new phosphorescent carbon nanostructure

Knoblauch

Bui

Raza

et al. 2018

Phys. Chem. Chem. Phys.

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Carbon nanodots are nanometer sized fluorescent particles studied for their distinct photoluminescent properties and biocompatibility. Although extensive literature reports the modification and application of carbon nanodot fluorescence, little has been published pertaining to phosphorescence emission from carbon nanodots. The use of phosphors in biological imaging can lead to clearer detection, as the long lifetimes of phosphorescent emission permit off-gated collection that avoids noise from biological autofluorescence. Carbon nanodots present a desirable scaffold for this application, with advantageous qualities ranging from photostability to multi-color emission. This research reports the generation of a novel phosphorescent "heavy carbon" nanodot via halogenation of the carbon nanodot structure. By employing a collection pathway that effectively incorporates bromine into the nanostructure, T1 triplet character is introduced, and subsequently phosphorescence is observed in liquid media at room temperature for the first time in the nanodot literature. Further experiments are reported characterizing the conditions of observed phosphorescence and its pH-dependence. Our approach for producing "heavy carbon nanodots" is a low-cost and relatively simple method for generating the phosphorescent nanodots, which sets the foundation for its potential future use as a phosphorescent probe in application.

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Section: 0 Materials and Methodsmentioning

confidence: 99%

Heavy carbon nanodots: a new phosphorescent carbon nanostructure

Knoblauch

Bui

Raza

et al. 2018

Phys. Chem. Chem. Phys.

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“…Moreover, similar to the room temperature case, the lifetimes are increased contrary to the typical lifetime reduction for the plasmon-enhanced fluorescence. − It could be explained by the fluorescence quenching weakening due to the decreasing exciton self-trapping efficiency. However, for the excimers, which are often considered as the smallest STE state, , fluorescence enhancement by plasmon resonance occurs in a similar way as for monomers. , Thus, one could not assume the direct suppression of the exciton self-trapping in the J-aggregates as a result of the exciton–plasmon interaction effect on this non-radiative process. Instead, the effect on the origin conditions for exciton self-trapping can be considered, like changing the exciton–phonon coupling. ,,− …”

Section: Resultsmentioning

confidence: 99%

Plasmon-Induced Suppression of Exciton Self-Trapping in Polymer-Bound Pseudoisocyanine J-Aggregates

et al. 2020

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Features of plasmon-enhanced fluorescence in pseudoisocyanine (PIC) J-aggregates formed in polyelectrolyte films at liquid nitrogen temperature have been studied. Due to efficient exciton self-trapping in polymer-bound PIC Jaggregates, their fluorescence spectra consist of two well-separated bands: a narrow near-resonant band belonging to free excitons and a wide red-shifted band assigned to self-trapped excitons. It has been found that in hybrid complexes composed of polymer-bound J-aggregates and gold nanoparticles placed on some optimal distance from J-aggregates, the interaction with plasmon resonance of gold nanoparticles leads to an increase in free-exciton fluorescence, whereas self-trapped exciton emission slightly decreases. Suppression of exciton self-trapping due to plasmon-induced enhancement of the exciton coherence length has been supposed and confirmed by a 2-fold decrease in the exciton−phonon coupling constant.

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“…As already mentioned, [23,45] the quenching degree of the excited states seems to be affected by structural factors, nanoparticle sizes/shape/number, and the agglomeration process, as well as the proximity between pyrene molecules from our photopolymer and the metal NPs present into the organic matrix (usually, no greater than 50 Å).…”

Section: Effect Of the In Situ Photogenerated Nanosilver Particlesmentioning

confidence: 99%

“…Based on the idea that some nanosized metallic structures can favorably modify the spectral properties of fluorophores through a resonance interaction in close proximity to surface plasmons, [23] the first choice was Figure 6. Fluorescence spectra of poly(VAc-co-AcrBzA)-Fl at different concentrations of NaOH (a) variation of the fluorescence intensity of poly(VAc-co-AcrBzA)-Fl (emission at 419 nm (1) and 535 nm (2)) and poly(VAc-co-AcrBzA-co-MAFl) (emission at 419 nm (3) and 535 nm (4)) at different concentrations of NaOH (b) and HCl (c).…”

Section: Effect Of the In Situ Photogenerated Nanosilver Particlesmentioning

confidence: 99%

“…On the other hand, in the literature, there is a new concept concerning fluorescence manipulation by metallic nanostructures that can modify the spectral properties of the fluorophores as the fluorescence lifetime, the fluorescence emission, and photobleaching, phenomenon named metal-enhanced fluorescence by Geddes [23]. Depending on the metal (gold, silver, platinum, cooper, etc), the size/shape of nanoparticles (NPs), the distance between entities (fluorophore, NPs), the excitation and emission wavelengths of the fluorophore, the degree of quenching and/or enhancement of fluorescence may be exploited in developing contrast agents for specific optical sensing and imaging.…”

Section: Introductionmentioning

confidence: 99%

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Preparation and characterization of novel p-acryloyloxybenzaldehyde copolymers bearing pyrene or fluorescein moieties. Interaction of fluorophore with some quenchers and silver nanoparticles

Buruiana¹,

Podasca²,

Buruiană³

2013

Designed Monomers and Polymers

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Two photopolymers, poly(vinyl acetate-co-p-acryloyloxybenzilideneiminepyrene) poly(VAc-co-AcrBzA)-Py and poly (vinyl acetate-co-p-acryloyloxybenzilideniminefluorescein) poly(VAc-co-AcrBzA)-Fl with pyrene and fluorescein in structure, have been prepared by chemical modification of the parent copolymer prior obtained through classical radical copolymerization. The structures of the polymers were characterized by FTIR, 1 H ( 13 C) NMR, UV, differential scanning calorimetry and thermogravimetric analysis, and gel permeation chromatography. The fluorescence properties of the photopolymers were investigated in dimethylformamide solutions containing various quenching agents (nitrobenzene, nitrophenol, p-nitrotoluene, picric acid, tetracyanoquinodimethane, Co 2+ , Hg 2+ , [UO 2 ] 2+ , NaOH, and HCl), the quenching efficiency varying in the next order: picric acid > TCNQ > p-nitrotoluene > nitrophenol. Quenching the fluorescence of fluoresceinimine occured only in acid medium (pH: 7.3-2.5) due to the protonated nitrogen, whereas with increasing basic pH (pH: 7.3-9.7) the fluorescence increased. Besides, fluorescence quenching or enhancement of fluorescence by silver nanoparticles (NPs) in situ photogenerated was investigated, our observations suggesting the role of polymer structure in stabilizing metal NPs in thin films.

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Metal-enhanced excimer (P-type) fluorescence

Cited by 17 publications

References 19 publications

Heavy carbon nanodots: a new phosphorescent carbon nanostructure

Heavy carbon nanodots: a new phosphorescent carbon nanostructure

Plasmon-Induced Suppression of Exciton Self-Trapping in Polymer-Bound Pseudoisocyanine J-Aggregates

Preparation and characterization of novel p-acryloyloxybenzaldehyde copolymers bearing pyrene or fluorescein moieties. Interaction of fluorophore with some quenchers and silver nanoparticles

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