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Photochemical activity and luminescence of dissolved oxygen molecules upon direct laser excitation under ambient conditions. A review of currently available resultsтезисы доклада
Информация о цитировании статьи получена из
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Дата последнего поиска статьи во внешних источниках: 25 апреля 2019 г.
- Автор: Krasnovsky A.A.
- Сборник: Proc. International Conference on laser optics (ICLO 2018), IEEE Xplor Digital library, p. 580 (DOI: 10.1109/LO.2018.8435519)
- Тезисы
- Год издания: 2016
- Место издания: IEEE Xplor Digital library
- Первая страница: 580
- Последняя страница: 580
- DOI: 10.1109/LO.2018.8435519
- Аннотация: Photochemical activity and luminescence of dissolved oxygen molecules upon direct laser excitation under ambient conditions. A review of currently available results A.A. Krasnovsky Jr. Federal Center for Biotechnology, A.N. Bach Institute of Biochemistry, Russian Academy of Science, Moscow, 119071, Russia phoal@mail.ru Abstract—The photochemical activities and luminescence of dissolved molecular oxygen upon direct laser excitation of the red, dark red and infrared oxygen spectral bands were studied using measurement of oxygenation rates of singlet oxygen traps and detection of IR (1270 nm) phosphorescence under ambient conditions. Summary of currently available results is presented. Biomedical importance of the data is discussed. Keywords— molecular oxygen, laser excitation, diode lasers, oxygen absorption spectra, singlet oxygen, IR phosphorescence, laser therapy, biological action I. INTRODUCTION It is known that molecular oxygen has the triplet ground state and two relatively low lying singlet states, whose zero and higher vibrational sublevels can be populated upon oxygen excitation. However, triplet-singlet transitions in oxygen molecules are highly forbidden. Therefore, corresponding absorption bands are extremely weak and cannot be reliably measured under ambient conditions. Therefore, until recent time, nothing was known about the absorption properties of oxygen dissolved in natural systems. Apparently, this information is of basic importance for oxygen photonics and understanding the state and function of oxygen molecules in chemical and biological systems. Interest to this problem was greatly stimulated by the suggestion that oxygen molecules might serve as photoreceptors causing biological and therapeutic action of laser and LED radiation. A decade ago our group started a project, which allowed us to strongly approach the solution of the above problems. We have shown that formation of singlet oxygen can be reliably detected upon direct laser excitation of oxygen in air-saturated solutions using oxygenation of singlet oxygen traps [1]. From kinetic analysis of oxygenation rates accurate absorption coefficients were obtained for oxygen absorption maxima at 765, 1070 and 1270 nm in several common organic solvents and water [2-9]. Recently, we extended our photochemical studies to oxygen excitation in red and dark red regions and compared the results with those obtained from detection of singlet oxygen phosphorescence upon direct oxygen excitation by laser radiation (see refs. in paper [9]). The present paper is aimed to summarize all currently available results of our group. II. METHODS, RESULTS AND DISCUSSION Measurements and analyses of the oxyge¬na¬tion rates of the singlet oxygen traps upon laser direct excitation of oxygen have been described elsewhere [6-9]. Recently, we assembled a spectrometer, which allowed detection of IR (1270 nm) luminescence of singlet oxygen upon direct excitation of oxygen at 765 nm and shorter wavelengths or upon photosensitized oxygen excitation of very low intensity. Scheme of this spectrometer was shortly reported in ref. [9]. Both methods were applied to measurement of the quantum efficiencies of singlet oxygen production by laser radiation. The photoactivity of oxygen was shown to strongly depend on environment. General discussion of experimental data is planned. ACKNOWLEDGEMENT This work was supported the Russian Foundation for Basic Research (project No 15-04-05500) and the program “Basic science for medicine” of the Russian Academy of Science. REFERENCES [1] Krasnovsky A.A., Drozdova N.N., Ivanov A.V., Ambartzumian R.V. Biochemistry (Moscow), 2003, vol. 68, 963-966. [2] Krasnovsky A.A, Ambartzumian R.V. Chem. Phys. Lett., 2004, 400, No 4-6, p. 531-535. [3] Krasnovsky A.A., Drozdova N.N., Ivanov A.V., Ambartzumian R.V. Chinese Opt. Letters, 2005, vol. 3 (supplement), S1-S4. [4] Krasnovsky A.A., Kryukov I.V., Sharkov A.V., Proc. SPIE, 2007, vol. 6535, 65351Q1- Q5. [5] Krasnovsky A.A., Rоumbal Ya.V., Strizhakov A.A., Chem. Phys. Lett., 2008, vol. 458, 195-199. [6] Krasnovsky A.A., Kozlov A.S., Rоumbal Ya.V. Photochem. Photobiol. Sciences, 2012, vol. 11, 988-997. [7] Krasnovsky A.A., Kozlov A.S., Biofizika, 2014, vol. 59, 250-257. [8] Krasnovsky A.A., Kozlov A.S., J. Photochem. Photobiol. A: Chemistry, 2016, vol. 329, 167-174. [9] Krasnovsky A.A., Kozlov A.S., Journal of Biomedical Photonics & Engineering, 2017, vol. 3, № 1, 010302: 1-10.
- Добавил в систему: Красновский Александр Александрович