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Nanofiber membranes generating singlet oxygen with magnetic separation
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polyurethane nanofiber membrane with encapsulated 5,10,15,20-meso-tetraphenylporphyrin (TPP) photosensitizer and maghemite nanoparticles. The membrane was prepared by electrospinning and shows effective photogeneration of O2 (1 Δg) and photoantibacterial effect on the surface. The membrane can be easily separated by a magnetic field. The magnetic behaviour of the maghemite nanoparticles was studied using Mössbauer spectroscopy. Their size was estimated by DLS. The final nanofiber membrane was characterized by UV-VIS, emission spectroscopy, and by electronic microscopy (SEM). The kinetics of O2 (1 Δg) generation was studied by time-resolved spectroscopy and the relative efficiency of photooxidation was studied using external acceptor of O2 (1 Δg). Significant photoantibacterial properties against bacteria strain Escherichia coli were detected on the surface of the membrane functionalized with TPP photosensitizer.
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Nanofiber membranes with encapsulated photoactive molecules simultaneously generating NO and 1O2 species
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polycaprolactone nanofibrous membrane with encapsulated NO photodonor 4-(N- (aminopropyl)-3-(trifluoromethyl)-4-nitrobenzenamine)-7-nitrobenzofurazan and photosensitizer chlorin e6. The electrospun nanofibrous membrane exhibits efficient photogeneration of NO and singlet oxygen molecules, which initiate facial and space photoantibacterial properties. The structure of the prepared NO photodonor was studied by NMR spectroscopy and UV-VIS absorption spectroscopy measurements. The resulting nanofibrous material was studied by scanning electron microscopy, and the successful encapsulation of both photoactive species was studied by absorption and fluorescence spectroscopy. Photogeneration of the NO molecule was studied by direct amperometric detection of NO and by reaction with a chemical substrate. The photogeneration of singlet oxygen O2( Δg 1 ) was studied by time-resolved spectroscopy and by reaction with a chemical substrate. Significant photoantibacterial properties were demonstrated on the bacterial strain Escherichia coli DH5α. Both antibacterial effects were studied by monitoring the number of colony forming units (CFU) using image analysis, and the facial effect by scanning electron microscopy. Keywords: singlet...
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Nanofiber membranes generating singlet oxygen with magnetic separation
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polyurethane nanofiber membrane with encapsulated 5,10,15,20-meso-tetraphenylporphyrin (TPP) photosensitizer and maghemite nanoparticles. The membrane was prepared by electrospinning and shows effective photogeneration of O2 (1 Δg) and photoantibacterial effect on the surface. The membrane can be easily separated by a magnetic field. The magnetic behaviour of the maghemite nanoparticles was studied using Mössbauer spectroscopy. Their size was estimated by DLS. The final nanofiber membrane was characterized by UV-VIS, emission spectroscopy, and by electronic microscopy (SEM). The kinetics of O2 (1 Δg) generation was studied by time-resolved spectroscopy and the relative efficiency of photooxidation was studied using external acceptor of O2 (1 Δg). Significant photoantibacterial properties against bacteria strain Escherichia coli were detected on the surface of the membrane functionalized with TPP photosensitizer.
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