Optical and structural properties of ensembles of colloidal Ag2S quantum dots in gelatin

Ovchinnikov, O. V.; Smirnov, M. S.; Shapiro, B. I.; Shatskikh, T. S.; Perepelitsa, A. S.; Korolev, N. V.

doi:10.1134/s1063782615030173

Cited by 45 publications

(21 citation statements)

References 34 publications

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“…A significant Stokes shift of the luminescence peak with respect to the absorption band and their halfwidth is a sign of the recombination nature of the observed luminescence in colloidal Ag 2 S QDs. This conclusion is consistent with the published data 600 700 λ, nm [33,42]. The analysis of the size dependence of the above luminescence band performed in [42] is evidence in favor of the recombination of electrons localized on the luminescence centers with vacant holes.…”

Section: Luminescent Properties Of the Mixtures Of Colloidal Ag 2 S Qsupporting

confidence: 93%

“…Their coupling with Dye molecules was carried out using the sol-gel technique. The preparation technique for the ensembles of hydrophilic colloidal solutions of Ag 2 S QDs with specified sizes is described in detail in [42,43]. The general approach consists in pouring aqueous solutions of the AgNO 3 and Na 2 S salts dissolved in 100 mL of distilled water into a reactor containing 200 mL of distilled water and 2% of inert photographic gelatin.…”

Section: Methodsmentioning

confidence: 96%

“…It is remarkable that the formation of the core/shell type nanoparticles, which are characterized by the development of crystalline cores with a size of 1.5 to 2.5 nm and by a shell composed of gelatin and its complexes, probably, with components of the QD synthesis, was observed in the investigated samples by analogy to the results reported in [42] (Fig. 2a).…”

Section: Methodsmentioning

confidence: 99%

“…It seems that a large deviation from the stoichiometric ratio of the monoclinic silver sulfide phase (Ag 2 -x S) exerts a considerable influence in this case. It is revealed in a significant concentration of the crystal structure defects [42,46], which serve not only as traps but also as radiative recombination centers. The last conclusion is confirmed by the presence of a noticeable area of the IR luminescence excitation of Ag 2 S QDs in this spectral range.…”

Section: Spectral Patterns Of the Formation Of Hybrid Associates In Tmentioning

confidence: 99%

“…This conclusion is consistent with the published data 600 700 λ, nm [33,42]. The analysis of the size dependence of the above luminescence band performed in [42] is evidence in favor of the recombination of electrons localized on the luminescence centers with vacant holes.…”

Section: Luminescent Properties Of the Mixtures Of Colloidal Ag 2 S Qmentioning

confidence: 99%

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The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

2016

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Spectral patterns of hybrid association in the mixture of colloidal Ag 2 S quantum dots (QDs) with an average size of 2.5 to 0.3 nm with J-aggregates of a pyridinium salt of 3,3'-di(γ-sulphopropyl)-9-ethyl-4,5,4',5-dibenzothiacarbocyanine betaine (Dye), prepared by the sol-gel method in gelatin, are investigated. A conclusion about the preferential formation of cis-J-aggregates in the hybrid associates of Dye with Ag 2 S QDs is made. The effect of photosensitization of IR luminescence (1000-1300 nm) of colloidal Ag 2 S QDs by J-aggregates of Dye is revealed. On the basis of the results, a photosensitization scheme implying the resonance nonradiative transfer of the electronic excitation energy from cis-J-aggregates to the recombination luminescence centers of Ag 2 S QDs is suggested.

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Section: Luminescent Properties Of the Mixtures Of Colloidal Ag 2 S Qsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

Section: Spectral Patterns Of the Formation Of Hybrid Associates In Tmentioning

confidence: 99%

Section: Luminescent Properties Of the Mixtures Of Colloidal Ag 2 S Qmentioning

confidence: 99%

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The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

2016

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Ag/Ag₂S Nanocrystals for High Sensitivity Near‐Infrared Luminescence Nanothermometry

Ruiz

Rosal

Acebrón

et al. 2016

Adv Funct Materials

118

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control, [4] luminescence thermometry (LTh) is rapidly expanding. In this case, thermal sensing is based on the appropriate analysis of temperature-dependent luminescence, leading to the appearance of Luminescent Nanothermometers (LNThs). [5] The main limitations of LNThs include: (i) the reading of temperatureinduced changes in the luminescence intensity from single emission lines and (ii) the short penetration depths of LNThs operating in the visible range [6] for in vivo applications along with autofluorescence background signals. [7] The former can be overcome by the use of ratiometric-based LNThs (hereafter RLNThs), [5a] in which the readout is extracted from the ratio between their photoluminescence (PL) intensity at different wavelengths, and the latter requires the use of NPs working in the near-infrared range (NIR), in particular in the second biological window (II-BW), expanding from 1000 to 1350 nm. [6b,8] Some examples of RLNThs working in the II-BW include singly and doubly rare earth doped NPs (RE-NPs) or the combination, in a single structure, of both RE-NPs and semiconductor quantum dots (QDs). [5c,9] In the case of rare earth doped NPs, their thermal sensitivity is lower than 0.5% °C −1 and the reduced absorption cross sections per NP leads to low signal-to-noise ratios during in vivo experiments. The combination of these two factors results in thermal Temperature sensing in biological media (cells, tissues, and living organisms) has become essential in the development of the last generation of diagnostics and therapeutic strategies. Thermometry can be used for early detection of different diseases, such as cancer, stroke, or inflammation processes, one of whose incipient symptoms is the appearance of localized temperature singularities. Luminescence nanothermometry, as a tool to accurately provide temperature sensing in biological media, requires the rational design and development of nanothermometers operating in the second biological window. In this work, this is achieved using Ag/Ag 2 S nanocrystals as multiparametric thermal sensing probes. Temperature sensing with remarkably high sensitivity (4% °C −1 ) is possible through intensity-based measurements, as their infrared emission is strongly quenched by small temperature variations within the biological range (15-50 °C). Heating also results in a remarkable redshift of the emission band, which allows for concentrationindependent temperature sensing based on infrared ratiometric measurements, with thermal sensitivity close to 2% °C −1 . These results make Ag/Ag 2 S nanocrystals the most sensitive among all noncomposite nanothermometers operating in the second biological window reported so far, allowing for deeptissue temperature measurements with low uncertainty (0.2 °C).

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Nonlinear optical characterization of colloidal solutions containing dye and Ag2S quantum dot associates

et al. 2016

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Optical and structural properties of ensembles of colloidal Ag2S quantum dots in gelatin

Cited by 45 publications

References 34 publications

The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

Ag/Ag₂S Nanocrystals for High Sensitivity Near‐Infrared Luminescence Nanothermometry

Nonlinear optical characterization of colloidal solutions containing dye and Ag2S quantum dot associates

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Optical and structural properties of ensembles of colloidal Ag2S quantum dots in gelatin

Cited by 45 publications

References 34 publications

The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

The formation and luminescent properties of hybrid associates of colloidal Ag2S quantum dots with J-aggregates of trimethinecyanine dye

Ag/Ag2S Nanocrystals for High Sensitivity Near‐Infrared Luminescence Nanothermometry

Nonlinear optical characterization of colloidal solutions containing dye and Ag2S quantum dot associates

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Product

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Ag/Ag₂S Nanocrystals for High Sensitivity Near‐Infrared Luminescence Nanothermometry