Photosensitized generation of singlet oxygen in powders and aqueous suspensions of silicon nanocrystals

Ryabchikov, Yury V.; Belogorokhov, I. A.; Gongal’skii, M. B.; Осминкина, Л. А.; Timoshenko, V. Yu.

doi:10.1134/s106378261108015x

Cited by 17 publications

(14 citation statements)

References 14 publications

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“…Molecular oxygen has the main triplet state with a spin of 1 ( 3 S) and two excited singlet states with a spin of 0 ( 1 D and 1 S), with transition energies of 0.98 and 1.63 eV, respectively. 122 Study of the nc-Si PL during the generation of singlet oxygen has shown the most reversible PL quenching at a wavelength corresponding to a quantum energy of B1.6 eV, which is related to oxygen excitation to the 1 S state 120,122 (Fig. 4).…”

Section: Excitation and Charge Transfer In Nanocomposites Based On Psimentioning

confidence: 99%

“…For peeling the pSi, the current density is drastically increased to B600 mA cm À2 for a short time at the final stage of etching. 120,121 It has been found 118,119 that energy is transferred from nc-Si to O 2 molecules via direct electron exchange (the Dexter transfer). Laser radiation in both the visible and UV regions is used to excite nc-Si.…”

Section: Excitation and Charge Transfer In Nanocomposites Based On Psimentioning

confidence: 99%

“…To date, it has been demonstrated that singlet oxygen may be generated on the nc-Si surface upon O 2 adsorption from the gas phase and both nonaqueous and aqueous solutions. 120,122 This last case is the most important for practical purposes. The energy transfer is highly efficient because the energy of excitons is close to the energy of electron transitions in the O 2 molecule.…”

Section: Excitation and Charge Transfer In Nanocomposites Based On Psimentioning

confidence: 99%

See 2 more Smart Citations

The photophysics of porous silicon: technological and biomedical implications

Kotkovskiy

Kuzishchin

Мартынов

et al. 2012

Phys. Chem. Chem. Phys.

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Although porous silicon (pSi) was first obtained in the mid-20th century, considerable interest in this material arose much later, due to the discovery of its room-temperature photoluminescence (PL). In the 1990s, most studies on pSi were focused on the analysis and explanation of its photoluminescent and electroluminescent characteristics and their potential practical applications. The latest advances in pSi research are related to its biocompatibility and biomedical applications. The discovery of singlet oxygen generation by pSi through nonradiative transfer of photoexcitation energy has opened new prospects for photodynamic therapy in vivo, and the discovery of laser desorption/ionization on pSi has paved the way for advanced approaches in mass-spectrometry. In this study, the main photophysical properties of pSi are reviewed, and a wide range of photo-processes characteristic of pSi and their practical implications are analyzed in terms of the general principles of energy and charge transfer. Special attention is paid to the possible applications of pSi and pSi-based nanocomposites in photonics, biophysics, medicine, and analytical chemistry.

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Section: Excitation and Charge Transfer In Nanocomposites Based On Psimentioning

confidence: 99%

Section: Excitation and Charge Transfer In Nanocomposites Based On Psimentioning

confidence: 99%

Section: Excitation and Charge Transfer In Nanocomposites Based On Psimentioning

confidence: 99%

See 1 more Smart Citation

The photophysics of porous silicon: technological and biomedical implications

Kotkovskiy

Kuzishchin

Мартынов

et al. 2012

Phys. Chem. Chem. Phys.

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“…The latter one is approximately proportional to N T at the partial oxygen pressure lower than the saturation one, i.e., when less than one monolayer of O 2 is adsorbed. 11,19 To apply the presented model for higher pressure, one needs to take into account adsorption isotherms and adsorption/desorption times ratio, e.g., it is reported in Refs. 11 and 19.…”

Section: Modelmentioning

confidence: 99%

Phenomenological model of photoluminescence degradation and photoinduced defect formation in silicon nanocrystal ensembles under singlet oxygen generation

Gongalsky

Timoshenko

2014

Journal of Applied Physics

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We propose a phenomenological model to explain photoluminescence degradation of silicon nanocrystals under singlet oxygen generation in gaseous and liquid systems. The model considers coupled rate equations, which take into account the exciton radiative recombination in silicon nanocrystals, photosensitization of singlet oxygen generation, defect formation on the surface of silicon nanocrystals as well as quenching processes for both excitons and singlet oxygen molecules. The model describes well the experimentally observed power law dependences of the photoluminescence intensity, singlet oxygen concentration, and lifetime versus photoexcitation time. The defect concentration in silicon nanocrystals increases by power law with a fractional exponent, which depends on the singlet oxygen concentration and ambient conditions. The obtained results are discussed in a view of optimization of the photosensitized singlet oxygen generation for biomedical applications. V C 2014 AIP Publishing LLC.

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“…Nanostructured silicon (nano-Si) is a perspective material due to its unique optoelectronic properties, resulting in potential applications in photovoltaics [1][2][3][4][5][6], nanothermometry [7][8][9], or nanoscale electronic devices [10,11]. Meanwhile, one of the most appealing prospects is related to the field of nanomedicine, in particular to drug delivery, singlet oxygen generation, magnetic resonance and optical bioimaging as well as cancer treatment [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Expedient paramagnetic properties of surfactant-free plasmonic silicon-based nanoparticles

Ryabchikov

Behrends

2020

Opt Quant Electron

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Surfactant-free multifunctional semiconductor-metallic nanostructures possessing several modalities are formed due to laser-induced structural modification of pure silicon nanoparticles in the presence of gold. It results to variable size-dependent chemical composition examined by energy-dispersive X-ray spectroscopy. Laser-synthesized silicon-based nanocomposites exhibit remarkable both plasmonic and paramagnetic properties. Their plasmonic maxima are found to be easily adjusted in the whole visible spectral range. Influence of resonant laser irradiation on spin behaviour of silicon-gold nanoparticles is established. Their spin-lattice and spin-spin relaxation processes are investigated as well. Such multifunctional nanoparticles can reveal a huge potential for different applications in field of nanomedicine, in particular, for biosensing and bioimaging.

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Photosensitized generation of singlet oxygen in powders and aqueous suspensions of silicon nanocrystals

Cited by 17 publications

References 14 publications

The photophysics of porous silicon: technological and biomedical implications

The photophysics of porous silicon: technological and biomedical implications

Phenomenological model of photoluminescence degradation and photoinduced defect formation in silicon nanocrystal ensembles under singlet oxygen generation

Expedient paramagnetic properties of surfactant-free plasmonic silicon-based nanoparticles

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