Hydrothermal evolution of PF-co-doped TiO2 nanoparticles and their antibacterial activity against carbapenem-resistant Klebsiella pneumoniae

Carbapenem-resistant Klebsiella pneumoniae (CP-Kp) is one of the most important opportunistic pathogens strongly associated with nosocomial infections. The capsule of CP-Kp not only contributes to its pathogenic potential but also ensures survival for bacteria in different environments and surfaces. Development of novel reactive nanomaterials can help to inhibit the survival of such microorganism and thereby their spreading in the hospital environment. In this work, the photocatalytic and antibacterial activities of PF-co-doped anatase TiO2 nanoparticles (NPs) were studied in details and related to the evolution of their structure and surface composition upon hydrothermal treatment at 250 degrees C for periods up to 12 h. Structural and morphological evolution were followed by X-ray diffraction, transmission electron microscopy while the surface composition was studied by X-ray photoelectron spectroscopy. Electron paramagnetic resonance measurements were carried out to reveal the formation of reactive oxygen species (ROS). Both OH center dot and O-2 center dot(-) radicals as well as O-1(2) were confirmed and quantitatively compared in different photoirradiated PF-TiO2 NPs dispersions. It was found that hydrothermal treatment increased the photocatalytic and antibacterial activity while PF-co-doping promoted the formation of OH center dot radicals. By the application of PF-co-doping, the elevated level of OH center dot led to rapid inactivation of CP-Kp.