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Eradication of Gram‐Positive and Gram‐Negative Bacteria by Photosensitizers Immobilized in Polystyrene
Author(s) -
Nakonechny Faina,
Pinkus Anna,
Hai Smadar,
Yehosha Ortal,
Nitzan Yeshayahu,
Nisnevitch Marina
Publication year - 2012
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12022
Subject(s) - polystyrene , chemistry , polymer , photosensitizer , methylene blue , bacteria , antimicrobial , solvent , chloroform , nuclear chemistry , chromatography , photochemistry , organic chemistry , photocatalysis , catalysis , biology , genetics
Immobilization of photosensitizers in polymers opens prospects for their continuous and reusable application. Methylene blue (MB) and R ose B engal were immobilized in polystyrene by mixing solutions of the photosensitizers in chloroform with a polymer solution, followed by air evaporation of the solvent. This procedure yielded 15–140 μm polymer films with a porous surface structure. The method chosen for immobilization ensured 99% enclosure of the photosensitizer in the polymer. The antimicrobial activity of the immobilized photosensitizers was tested against G ram‐positive and G ram‐negative bacteria. It was found that both immobilized photosensitizers exhibited high antimicrobial properties, and caused by a 1.5–3 log 10 reduction in the bacterial concentrations to their total eradication. The bactericidal effect of the immobilized photosensitizers depended on the cell concentration and on the illumination conditions. Scanning electron microscopy was used to prove that immobilized photosensitizers excited by white light caused irreversible damage to microbial cells. Photosensitizers immobilized on a solid phase can be applied for continuous disinfection of wastewater bacteria.