Photoexcitation dynamics in hybrid associates of Ag2S quantum dots with methylene blue

Hybrid associates formed from colloidal Zn0.5Cd0.5S quantum dots, passivated with thioglycolic acid, europium tenoyltrioteracetonate and methylene blue molecules, absorption, luminescence, IR and time-resolved spectroscopy technique are studied. The shift of the IR absorption bands of COO- and C=O groups of thioglycolic acid and europium thenoyltrifluoroacetonate has been detected. An increase in the efficiency of excitation of europium luminescence and a simultaneous increase lifetime of its luminescence upon adsorption on Zn0.5Cd0.5S quantum dots were found. Addition of methylene blue (thionine) molecules leads to quenching of the trap state luminescence of Zn0.5Cd0.5S and intracentric luminescence of Eu3+. A conclusion about the adsorption of Eu3+ on the surface of Zn0.5Cd0.5S quantum dots and the nonradiative energy transfer to methylene blue molecules was made.

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Spectroscopic investigation of colloidal CdS quantum dots–methylene blue hybrid associates

Journal of Nanoparticle Research ◽

10.1007/s11051-014-2286-5 ◽

2014 ◽

Vol 16 (3) ◽

Cited By ~ 36

Author(s):

Oleg V. Ovchinnikov ◽

Michail S. Smirnov ◽

Tamara S. Shatskikh ◽

Vladimir Yu. Khokhlov ◽

Boris I. Shapiro ◽

...

Keyword(s):

Methylene Blue ◽

Quantum Dots ◽

Spectroscopic Investigation ◽

Cds Quantum Dots ◽

Hybrid Associates ◽

Colloidal Cds

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Luminescence properties of hydrophilic hybrid associates of colloidal CdS quantum dots and methylene blue

Journal of Luminescence ◽

10.1016/j.jlumin.2014.08.026 ◽

2014 ◽

Vol 156 ◽

pp. 212-218 ◽

Cited By ~ 23

Author(s):

M.S. Smirnov ◽

O.V. Ovchinnikov ◽

T.S. Shatskikh ◽

A.G. Vitukhnovsky ◽

S.A. Ambrozevich ◽

...

Keyword(s):

Methylene Blue ◽

Quantum Dots ◽

Luminescence Properties ◽

Cds Quantum Dots ◽

Hybrid Associates ◽

Colloidal Cds

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Transient absorption spectral dynamics of hybrid associates of CdS quantum dots and methylene blue dye

Doklady of the National Academy of Sciences of Belarus ◽

10.29235/1561-8323-2021-65-3-281-289 ◽

2021 ◽

Vol 65 (3) ◽

pp. 281-289

Author(s):

S. A. Tikhomirov

Keyword(s):

Methylene Blue ◽

Quantum Dots ◽

Energy Transfer ◽

Transient Absorption ◽

Blue Dye ◽

Cds Quantum Dots ◽

Hybrid Associates ◽

Reduced Forms ◽

Methylene Blue Cationic Dye ◽

Colloidal Cds

The transient absorption spectra dynamics for hybrid associates of colloidal CdS quantum dots, passivated by thioglycolic acid (CdS/TGA QDs), and methylene blue cationic dye molecules (MB+) were studied by femtosecond spectroscopy. It was established that one of the main channels of relaxation of the CdS/TGA QDs excitation energy in hybrid associates based on CdS/TGA QDs and MB+ is a fast energy transfer to the reduced forms of MB+ (MBOH•, MB•) that are formed still at the synthesis stage of samples. This channel strongly competes with the resonant energy transfer from the centers of radiative recombination in quantum dots to MB+. Therefore, for hybrid associates based on QDs/TGA and methylene blue, there is no any noticeable signal of the transient absorption corresponding to the triplet state of MB+ dye, which is then known to be actively involved in charge transfer.

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