ISSN 19950780, Nanotechnologies in Russia, 2013, Vol. 8, Nos. 1–2, pp. 122–128. © Pleiades Publishing, Ltd., 2013. Original Russian Text © N.A. Kuznetsova, O.A. Yuzhakova, A.S. Kozlov, A.A. Krasnovskii, M.G. Strakhovskaya, O.L. Kaliya, 2013, published in Rossiiskie Nanotekhnologii, 2013, Vol. 8, Nos. 1–2.
Effect of SupportPore Size on Activity of Heterogeneous Photosensitizer Based on Phthalocyanine Covalently Grafted to Aminopropylated Silica Gel N. A. Kuznetsovaa, O. A. Yuzhakovaa, A. S. Kozlovb, A. A. Krasnovskiib, c, M. G. Strakhovskayac, and O. L. Kaliyaa a
b
State Scientific Center NIOPIK, Bolshaya Sadovaya ul. 1, korp. 4, Moscow, 123999 Russia Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 119071 Russia c Faculty of Biology, Moscow State University, Moscow, 119992 Russia email:
[email protected] Received May 16, 2012; accepted October 10, 2012
Abstract—New heterogeneous photosensitizers in which the active phase, aluminum (polycholinyl)tetra3 phenylthiophthalocyanine, was covalently grafted to aminopropylated silica gels with pore sizes of 10, 25 and 75 nm have been synthesized. It is found that phthalocyanine cannot penetrate into 10nm pores. Access to the pores increases with the increase in the pore size, resulting in the active phase being located predomi nantly inside pores in samples having 75nm pores. It is demonstrated that the active phase is capable of flu orescence, singletoxygen photogeneration, and photobactericidal activity in aqueous suspensions of the het erogeneous photosensitizers, with the efficiency of these processes being higher for the dye molecules located on the surface of the support rather than inside the pores. DOI: 10.1134/S1995078013010084
The immobilization of functional dyes on porous silica gel is an important approach to developing sen sors [1], phases for highperformance liquid chroma tography [2], and heterogeneous catalysts and photo catalysts for liquid media [3, 4]. Heterogeneous sensi tizers for singletoxygen formation are particularly of interest both for the purification of water from organic contaminants [5, 6] and for photoinactivation of bac teria and viruses in liquids [7, 8]. Singlet oxygen is gen erated by an active phase of heterogeneous sensi tizer—a dye immobilized on the support surface— under the action of light. Upon the absorption of a light quantum, the dye goes into a singlet state and, subsequently, in a triplet excited state as a result of intersystem crossing. The formation of reactive singlet oxygen occurs as a consequence of energy transfer from the dye triplet state to oxygen [9]. Previously [10] we have synthesized new heteroge neous photosensitizers based on substituted tetra(phe nylthio)phthalocyanines of zinc and aluminum as an active phase, where phthalocyanines are covalently bound with aminopropylated silica gel. The spectral luminescent properties of the photosensitizers, their effectiveness in generating singlet oxygen, and photo bactericidal activity against E. coli bacteria (strain pXen7) in aqueous medium have been studied. It was shown that the synthesized heterogeneous photosensi tizers have photodynamic activity and are potentially
suitable for the photodynamic disinfection of water and biological fluids. At the same time, the effect of the support pore size on the character of immobiliza tion of the active phase, as well as the activity of the obtained heterogeneous systems, were not studied. In the present work, we studied the influence of the size of the support pore on the physicochemical properties and the activity of the heterogeneous sensitizer. A photosensitizer based on aminopropylated silica gel with aluminum (polycholinyl)tetra3phenylthio phthalocyanine (PcI) covalently grafted thereon (Fig. 1) with active phase loading of 1 and 5 μmol per 1 g was chosen as a model. The supportpore size was equal to 10, 25, and 75 nm (supports Diasorb100 amine, Dia sorb250 amine, and Diasorb750 amine, respec tively). Photocatalysts were prepared by the procedure developed in work [10], according to which aluminum (oktakischloromethyl)tetra3phenylthiophthalocya nine is firstly grafted to the support, followed by its transformation in PcI through treatment with N,N dimethylaminoethanol. The degree of application of PcI was equal to 1 μmol/g (for A10, A25, and A75 sen sitizers depending on the pore size) and 5 μmol/g (for B10, B25, and B75, respectively). Visually, the color intensity decreases significantly in both series of sensitizers with an increase in the pore size (Fig. 2). This indicates that PcI is predominantly located inside the pores of a support with large pores and on the surface of a support with small pores. Silica
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OH
HO
HO
Cl N
Cl N
H2C
CH2
Cl N CH2 S
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OH N CH2
N
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N S
H2C N HO
Cl
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N
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OH
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Fig. 2. Samples of B10 (1), B25 (2), and B75 (3) sensitizers.
S
CH2
Despite substantial differences in the visual colora tion of powder samples with different pore sizes, the electron absorption spectra of their coarse suspensions in glycerol demonstrate approximately the same col oration and intensity of absorption bands (Fig. 3). This is probably due to the high coefficient of light refrac tion of glycerol, which is close to the refraction coeffi cient of silica gel, which is why the light is absorbed equally by PcI molecules located outside and inside the pores.
CH2
N Cl OH
NH
O
SiO2 Fig. 1. Structure of a heterogeneous sensitizer which is aminopropylated silica gel with covalently grafted alu minum (polycholinyl)tetra3phenylthiophthalocyanine thereon.
gel is transparent; however, the light is substantially reflected by its surface and does not penetrate the pores due to the high difference between light refrac tion coefficients of air and silica gel. Therefore, color ation is only due to the phthalocyanine located on the surface, and a more intensive coloration of samples with small pore sizes indicates the predominant loca tion of PcI on the surface of particles of such a silica gel. This conclusion is in agreement with the relative pore size and diameter of the PcI molecule. The diam eter of the PcI molecule inclusive of bulky substituents is about 5 nm. One may assume that these molecules penetrate poorly into the 10 nm pores having amino propyl groups on the inner surface, further hindering the approach of the dye into the pores. The dye is mainly located on the support surface in this case. When the pore size increases to 75 nm, PcI molecules easily penetrate silica gel pores and uniformly distrib ute themselves over its entire internal and external sur face. In this case, PcI is predominately located inside the pores, the surface of which dominates. It is obvious that in order to ensure the effective penetration of the dye into the pores their diameter should be more than 20 nm. NANOTECHNOLOGIES IN RUSSIA
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As can be seen from Fig. 3, the absorption spectra of coarse suspensions of silica gels with immobilized PcI in glycerol are strongly broadened, and the absorp tion maxima of the bands are strongly shifted when compared with those of solutions. Nevertheless, they have an intense absorption band Q with a vibration satellite in the shortwave length region. Such a char acter of the spectrum indicates highcontent photo chemically active monomers in the active phase. At a low content of PcI (1 μmol/g, the A series), the absorption spectra of glycerol suspensions are identi cal regardless of the pore size, which indicates the same and, probably, predominantly the monomeric state of the dye. A tendency to higher broadening and shifting of the Q absorption band in the longwave length region upon a decrease in pore size is observed in the spectra of samples with high PcI contents (5 μmol/g), as is shown in Fig. 3. These data may indi cate the appearance of dye aggregates. Since the recorded absorption spectra of large par ticle suspensions are always distorted by superposition with optical effects, which are due to light scattering and the inhomogeneous distribution of absorbing molecules in volume, detailed studies of the optical properties of heterogeneous sensitizers were also car ried out for their fine dispersions prepared [10] using an ultrasonic treatment in 0.2 M detergent aqueous solution (sodium dodecyl sulfate (SDS)). These sus pensions made it possible to perform more accurate spectral, luminescent, and photochemical measure ments, the results of which are presented in Fig. 4 and the table. 2013
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2
0.2
4
3
0.1 0 300
350
400
450
500 550 600 Wavelength, nm
650
700
750
Fig. 3. Electronic absorption spectra of PcI in water (1) and of large particle suspensions of B75 (2), B25 (3), and B10 (4) heter ogeneous sensitizer in glycerol (4 g/L).
If, OD, rel. units 1.0 (a)
1
If, OD, rel. units 1.0 (b)
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2
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0 600
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0 600
700 800 Wavelength, nm
700 800 Wavelength, nm
Fig. 4. Normalized absorption (1) and fluorescence (2) spectra of fine aqueous dispersions of A75 (a) and B75 (b) samples in the presence of 0.2M sodium dodecyl sulfate. The absorption spectra were measured in units of optical density equal to 0.25 in the absorption maximum. The fluorescence spectra were measured at λexc = 650 nm; a correction for the spectral sensitivity of the spectrofluorimeter was applied. If is the fluorescence intensity; OD is optical density of the suspension.
Figure 4 shows the normalized absorption and flu orescence spectra of aqueous suspensions of sensitiz ers A75 and B75 in the presence of 0.2 M SDS as an example. It is seen from the figure that longwave length absorption bands of these samples are almost identical. The maximum is located at 738 nm with a shoulder in the region of 675 nm. Such absorption spectra were obtained for all samples of the A and B series. The halfwidth of the Q band is 63 ± 1 nm (~1200 cm–1), which is lower than the value observed for the largeparticle suspensions in glycerol (∼120 nm, Fig. 1), but still substantially higher (by 2– 3 times) than the halfwidth of the absorption band of monomer dye solution (∼28 nm or 615 cm–1). Based on the literature data, such broadening is characteris tic of immobilized dyes, both adsorbed and chemically grafted to the support, and is due to the interaction of πorbitals of the conjugated system with the support.
The fluorescence spectrum of the heterogenious sensitizer is shifted to longer wavelengths compared to the absorption spectrum and is a mirror reflection thereof. The fluorescence excitation spectrum (Fig. 5) shows that the fluorescence is due to the active phase, i.e., phthalocyanine, since the excitation spectrum contains the all main absorption bands of monomeric phthalocyanine. In accordance with the results of the spectral anal ysis, we observed that the fluorescence yield decreases with the increase in the concentration of phthalocya nine on the support, which is apparently due to the increase in the fraction of aggregates. However, the quantum yield of fluorescence increased with the decrease in the silicagel pore size (at the same con centration of the dye). One may assume that the fluo rescence corresponded mostly to РсI molecules dis tributed over the silica gel surface outside the pores.
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It is possible that the decrease in the observed ΦF upon the increase in the pore size is due to the fact that, in this case, more and more phthalocyanine molecules are located inside the pores and emit fluorescence, which is reflected by their internal surface. Figure 6 illustrates one of the experiments on the sensitized photobleaching of a singletoxygen scaven ger (diphenylisobenzofuran (DPBF)) in aqueous sus pensions of heterogeneous sensitizers in the presence of SDS. As is seen from the figure, the absorption of DPBF (λmax = 414 nm) decreases quickly upon the irradiation of B25 suspension in the region of the РсI absorption maximum. The РсI absorption band does not change in this case, which indicates reasonable photostability of the active phase. Sodium azide, a sin glet oxygen quencher, markedly reduced the rate of photosensitized oxidation of DPBF, confirming, therefore, the participation of singlet oxygen in the process. The values of the quantum yield of singletoxygen generation by the heterogeneous sensitizers indicate that they generate singlet oxygen with moderate effi ciency: quantum yields ΦΔ achieve 0.2. Similar value was also obtained for monomeric PcI in DMSO. The yield of singlet oxygen upon the low loading of phtha locyanine (the A series) is somewhat higher than for the B series with a higher dye content. This effect is qualitatively analogous to that observed upon measur ing the dye fluorescence yields (see the table) and is apparently due to the appearance of photochemically inactive aggregates at high concentrations of the active phase. The tendency to an increase in the yield of sin glet oxygen upon the reduction in the pore size also persists, although it is expressed more weakly than in the case of fluorescence. It seems that the generation of singlet oxygen is mainly provided by dye molecules Intensity, rel. units 24
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Spectralluminescent characteristics and quantum yields of singletoxygen generation for heterogeneous sensitizers (suspensions in a 0.05M sodium dodecyl sulfate aqueous solution) Sample A10 A25 A75 B10 B25 B75
abs F λ max , nm λ max , nm ΦF (±10%) ΦΔ (±20%)
738 738 738 738 738 738
748 748 748 758 758 758
0.21 0.14 0.09 0.09 0.06 0.03
0.23 0.21 0.22 0.19 0.12 0.10
located on the surface of the support rather than in its pores. It is noteworthy that the sum of the quantum yields of fluorescence and singletoxygen photogeneration is considerably lower than 1. This makes it possible to suppose that dyes bound to silica gel acquire a nonra diative channel for the deactivation of the singlet excited state. Nevertheless, on the whole, PcI on silica gel retained significant photosensibilizing activity. The photobactericidal activity of the heteroge neous photosensitizers was evaluated by the photoin activation of a biosensor, namely, a genetically engi neered luminescent strain of E. coli bacteria (pXen7). In the preliminary experiments it was found that the pronounced photobactericidal effect for the heteroge neous photosensitizers under investigation (biolumi nescence quenching) manifests itself at an active phase concentration of 20 μM. The incubation of bacteria in the absence of irradiation at a temperature of 20–22°C for 10 min with heterogeneous photosensitizers at a corresponding concentration did not result in a reduc
Optical density 1.2
16 0.6
8
0 300
400
500 600 Wavelength, nm
700 0 400
Fig. 5. Fluorescence excitation spectrum for PcI phthalo cyanine in the A10 sample upon the recording of fluores cence at a wavelength of 770 nm. The width of the mono chromator slit was 5 nm. The optical density in the long wavelength absorption maximum was ∼0.2 for a 1cm cell. NANOTECHNOLOGIES IN RUSSIA
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Fig. 6. Effect of irradiation at 740 nm on the absorp tion spectra of the aqueous suspension containing B25, 1,3diphenylisobenzofuran and 0.2M sodium dodecyl sulfate. 2013
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rather high photostability, with a reduction in the activity at a dose of 540 kJ/cm2 corresponding to about 20% for B10 and B25 and up to 10% for B75.
Photobactericidal activity, % 100 90
3
80
2 1
As follows from Fig. 7, the photostability of the heterogeneous photosensitizers slightly increases with an increase in the supportpore size. The lowest pho tostability has a B10 sample. It seems that phthalocy anine molecules on the support surface are prone to higher photodegradation than those inside the pores. This may be due to light scattering reducing the light dose entering the pores.
70 1 cycle
2 cycle
3 cycle
60 50 0
180 360 540 Whitelight dose, kJ/cm2
Fig. 7. Change in the photobactericidal activity of the het erogeneous B10 (1), B25 (2), and B75 (3) sensitizers towards E. coli pXen7 bacteria depending on the light dose.
tion of the bioluminescence level (survival) of bacte ria, which indicates the absence of dark toxicity of sen sitizers. The incubation of the biosensor with supports without the active phase did not result in biolumines cence quenching either. A study on the comparative photobactericidal activity of the heterogeneous photosensitizers at a concentration of 4 g/L (which is equal to the concen tration of the active phase of 20 μM) showed that the whitelight dose resulting in the 50% inactivation of E. coli pXen7 bacteria was equal to 135, 156, and 168 J/cm2 for B10, B25, and B75, respectively. The reduction of the light dose upon a decrease in pore size gives evidence of an increase in the photobactericidal effect. The changes revealed are not great; however, they make it possible to conclude that the phthalocya nine located on the support surface is more active than that inside the pores. To study the effect of the support pore size on the stability of the photobactericidal action of the hetero geneous photosensitizers, experiments with several cycles of their use were carried out. In these experi ments, after the irradiation of a suspension of biolumi nescent bacteria containing a photosensitizer with white light in a dose of 180 J/cm2 (for 60 min), the supernatant liquid with treated bacteria was separated and fresh bacteria were added to the sediment of the heterogeneous sensitizer. The suspension was incu bated again for 10 min upon stirring and then irradi ated with white light. Figure 7 illustrates a change in the photobactericidal activity of the heterogeneous sensitizers B10, B25, and B75 depending on the whitelight dose received in three cycles. The experi ments showed that aluminum phthalocyanine PcI chemically grafted to aminopropylated silica gel has
Thus, this study suggests that the PcI sensitizer does not penetrate 10 nm pores in the process of chemical grafting to aminopropylated silica gel. When the pore size of silica gel increases to 25–75 nm, PcI penetrates the pores and is predominately located inside the pores. The fluorescence, generation of sin glet oxygen, photodegradation of the active phase, and photobactericidal effect are higher for the systems having dye molecules on the support surface rather than inside the pores. Probably this effect is associated with light scattering from the surface of silica gel reducing the light dose penetrating the pores. EXPERIMENTAL PART Aminopropylated silica gels Diasorb100 amine, Diasorb250 amine, and Diasorb750 amine manu factured by ZAO BioChemMakST had the following characteristics, respectively: pore diameters of 10, 25, and 75 nm; grain sizes of 63–200, 100–200, and 40– 100 μm; specific surfaces of 330, 100, and 40 m2/g; and aminopropylsilyl group loaded in amounts of 1.4, 0.4 and 0.4 mmol/g. Aluminum tetraphenylth iophthalocyanine was prepared by the procedure [11]. Chloromethylation of aluminum tetraphenylth iophthalocyanine was carried out as described in patent [12]. Analytical data for hydroxyaluminum tetrakis[(dichloromethyl)phenylthio]phthalocyanine Al(OH)Pc(SPhClm2)4: found, %: Cl 20.02; calculated, %: Cl 20.59. Grafting of hydroxyaluminum tetrakis[(dichlo romethyl)phenylthio]phthalocyanine to aminopropy lated silica gels and the subsequent treatment of the resulting heterogeneous product with N,N–dimethy laminoethanol in order to convert chloromethyl groups in the phthalocyanine molecule into cholenyl ones was conducted according to procedure [10]. The electronic absorption spectra were recorded on a Hewlett Packard 8453 spectrophotometer. The pow ders of heterogeneous sensitizers were dispersed in glycerol to get a concentration of 4 g/L. When record ing the absorption spectra, a suspension of undyed support taken in the same concentration was placed in the comparison cell of the spectrophotometer.
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The fluorescence was measured on a PerkinElmer 44B computerized spectrofluorimeter. To reduce the contribution of light scattering, maximally diluted suspensions of sensitizers prepared as follows were used. The initial samples were thoroughly ground in a mortar and the resulting powder was added in an aque ous 0.05 or 0.2M SDS solution (Merck, Germany) followed by additional dispersion by ultrasound for 15 min. As a result, fine dispersions stable for several hours were formed. The particle size of these suspen sions was equal to more than 200 nm. To minimize the reabsorption of fluorescence, suspensions with optical densities of no more than 0.2 in the region of absorp tion maximum located at the longest wavelength were used to conduct the measurements. The optical den sity in the excitation region (640–650 nm) was equal to 0.035–0.45 in this case. To determine the quantum yield of fluorescence (ΦF), aqueous solutions of tetrasulfophenylporphyrin (TSPP), where the quantum yield of its fluorescence is known to be 0.08 [3], were used as a reference. The error of ΦF determination was no more than ±5%. The quantum yields of singlet oxygen (ΦΔ) were determined from the photobleaching of 1,3diphenyl isobenzofuran (DPBF) (Aldrich, United States) solu bilized in 0.2 M aqueous solutions of SDS [14]. For this purpose concentrated acetone solutions of DPBF were added to the aqueous suspensions of the hetero geneous sensitizers, containing 0.2 M SDS. The final acetone concentration in the sample was 3%; the con centration of DPBF was about 40 μM. TSPP in 0.2 M aqueous detergent solution (ΦΔ = 0.7 [15]) was used as a reference. A halogen lamp with a KC15 cutoff glass filter transmitting red light with λ > 640 nm was used to irradiate a spectroscopic cell. The power of lumi nous flux falling on the sample was equal to about 1.5 mW. The volume of the samples was 2.5 mL. The photosensitized oxidation of the singlet oxygen scav enger was controlled spectrophotometrically by decreasing of optical density in the maximum of DPBF at 414 nm. The curves of dependence of con sumption of the scavenger on the irradiation time were compared in photosensitizer and reference solutions. The rate of photobleaching of the trap (W) was deter mined graphically from the initial section of the kinetic curve of DPBF photooxidation. The quantum yields ΦΔ were calculated by Eq. (1), which is valid if the equal concentrations of the trap were used in suspensions of the sensitizers and the ref erence: ref
ref WI abs Φ Δ = Φ Δ , ref W I abs
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ref
where Φ Δ is the singletoxygen quantum yield for the TSPP reference; W and W ref are the trap photobleach ing rates in the presence of the sensitizer under inves tigation and the reference, respectively. EVALUATION OF PHOTOBACTERICIDAL ACTIVITY OF HETEROGENEOUS PHOTOSENSITIZERS To determine the photobactericidal activity of the heterogeneous photosensitizers, a bacterial biolumi nescent test system based on the genetically engi neered E. coli strain (pXen7) [16], the biolumines cence of which is due to the cloned full luxoperon from luminous soil entomopathogenic bacteria Photo rhabdus luminescens, was used. The intensity of lumi nescence of the bacteria incubated with heteroge neous photosensitizers before and after irradiation was recorded using a Biotox6 luminometer (Moscow) in a 1.5mL cell containing 1 mL of the sample under investigation at room temperature. A 2 mL suspension of E. coli pXen7 bacteria in distilled water with a bac terial concentration of 3 × 107 CFU/mL and a hetero geneous photosensitizer in an active phase concentra tion of 20 μM were placed in a test tube. The samples were incubated in the dark at room temperature (20– 22°C) for 10 min with stirring. The test sample was irradiated with white light from an EKOMP source. The light intensity measured using OPHIR Optronics (Israel) at a distance of 5 cm from the end of a light guide was equal to 50 mW/cm2. The irradiation of the test sample and the incubation of the dark reference were conducted at temperatures of 20–22°C with stir ring on a magnetic stirrer. After the completion of irra diation and dark incubation for 2 min, the support was allowed to settle out at the bottom and 1 mL of super natant suspension of bacteria was taken to measure the bioluminescence. Each experiment was conducted 3– 4 times. ACKNOWLEDGMENTS This work was supported by the Moscow City Gov ernment and the Russian Foundation for Basic Research (projects no. 100300444, 100300750a). REFERENCES 1. A. Walcarius, “Electrochemical Applications of Silica Based OrganicInorganic Hybrid Materials,” Chem. Mater. 13 (10), 3351–3372 (2001). 2. B. Görlach, C. Hellriegel, S. Steinbrecher, H. Yüksel, K. Albert, E. Plies, and M. Hanack, “Synthesis, Char acterization and HPLCApplications of Novel Phtha locyanine Modified Silica Gel Materials,” J. Mater. Chem. 11, 3317–3325 (2001). 3. D. Wohrle, O. Suvorova, R. Gerdes, O. Bartels, L. Lapok, N. Baziakina, S. Makarov, and A. Slodek, “Efficient Oxidations and Photooxidations with 2013
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4.
5.
6.
7.
8.
9.
KUZNETSOVA et al. Molecular Oxygen Using Metal Phthalocyanines as Catalysts and Photocatalysts,” J. Porphyrins Phthalo cyanines 8, 1020–1041 (2004). Y. Fueda, H. Suzuki, Y. Komiya, Y. Asakura, T. Shira gami, J. Matsumoto, H. Yokoiand, and M. Yasuda, “Bactericidal Effect of Silica GelSupported Porphyri natophosphorus(V) Catalysts in Escherichia coli under VisibleLight Irradiation,” Bull. Chem. Soc. Jpn. 79 (9), 1420–1425 (2006). V. Iliev, A. Ileva, and L. Bilyarska, “Oxidation and Pho tooxidation of SulfurContaining Compounds in the Presence of Immobilized Phthalocyanine Complexes,” J. Mol. Catal. A: Chem. 126, 99–108 (1997). E. Pepe, O. Abbas, C. Rebufa, M. Simon, S. Lacombe, and M. Julliard, “Supported Photosensitizers for the Visible Light Activation of Phenols towards Oxygen,” J. Photochem. Photobiol. A: Chem. 170, 143–149 (2005). J. Mosinger, K. Losinska, T. Abrhamova, S. Veiserova, Z. Micka, I. Nemcova, and B. Mosinger, “Determina tion of Singlet Oxygen Production and Antibacterial Effect of Nonpolar Porphyrins in Heterogeneous Sys tems,” Analyt. Lett. 33 (6), 1091–1104 (2000). I. M. Belousova, O. B. Danilov, T. D. Murav’eva, I. M. Kislyakov, V. V. Ryl’kov, T. K. Kris’ko, O. I. Kise lev, V. V. Zarubaev, A. K. Sirotkin, and L. B. Piotrovskii, “SolidPhase Photosensitisers on the Base of C60 Fullerene for Photodynamic Viruse Inactivation in Biological Liquids,” Opt. Zh. 76 (4), 97–107 (2009). A. Krasnovsky, “Primary Mechanisms of Photoactiva tion of Molecular Oxygen. History of Development and
10.
11.
12. 13.
14.
15.
16.
the Modern Status of Research,” Biochem. (Moscow) 72 (10), 1065–1080 (2007). N. Kuznetsova, O. Yuzhakova, M. Strakhovskaya, A. Shumarina, A. Kozlov, A. Krasnovsky, and O. Kaliya, “New Heterogeneous Photosensitizers with Phthalo cyanine Molecules Covalently Linked to Aminopropyl Silica Gel,” J. Porphyrins Phthalocyanines 15, 718– 726 (2011). V. M. Derkacheva and E. A. Luk’yanets, “Phthalocya nines and Related Compounds. XVIII. Phenoxy and PhenylthioSubstituted Phthalocyanines,” Zh. Organ. Khim. 50 (10), 2313–2318 (1980). RF Patent No. 2405785 (2010). K. Kalyanasundaram and M. NeumannSpallart, “Photophysical and Redox Properties of WaterSoluble Porphyrins in Aqueous Media,” J. Phys. Chem. 86 (26), 5163–5169 (1982). A. A. Krasnovsky, Y. V. Roumbal, and A. A. Strizhakov, “Rates of 1O2 (1Δg) Production upon Direct Excitation of Molecular Oxygen by 1270 nm Laser Radiation in AirSaturated Alcohols and Micellar Aqueous Disper sions,” Chem. Phys. Lett. 458 (1–3), 195–199 (2008). F. Wilkinson, W. P. Helman, and A. B. Ross, “Quantum Yields for the Photosensitized Formation of the Lowest Electronically Excited Singlet State of Molecular Oxy gen in Solution,” J. Phys. Chem. Ref. Data 22 (1), 113–262 (1993). M. G. Strakhovskaya, A. P. Zarubina, V. G. Zhukho vitskii, A. F. Mironov, and A. B. Rubin, “Biolumines cent Genetically Engineered Bacteria as a New Effi cient Instrument for Researching Photosensitisers Activity,” Dokl. Akad. Nauk 396, 177–180 (2004).
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