Journal

J. Mater. Chem. B, 2014, 2, 1307

Authors

M. Mohl, A. Dombovari, E. S. Tuchina, P. O. Petrov, O. A. Bibikova, I. Skovorodkin, A. P. Popov, A.-R. Rautio, A. Sarkar, J.-P. Mikkola, M. Huuhtanen, S. Vainio, R. L. Keiski, A. Prilepsky, A. Kukovecz, Z. Konya, V. V. Tuchin, K. Kordas

Abstract

Further developments of antibacterial coatings based on photocatalytic nanomaterials could be a promising route towards potential environmentally friendly applications in households, public buildings and health care facilities. Hereby we describe a simple chemical approach to synthesize photocatalytic nanomaterial-embedded coatings using gypsum as a binder. Various types of TiO2 nanofiber-based
photocatalytic materials (nitrogen-doped and/or palladium nanoparticle decorated) and their composites with gypsum were characterized by means of scanning (SEM) and transmission (TEM) electron microscopy as well as electron and X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy
(EDX) techniques. These gypsum-based composites can be directly applied as commercially available
paints on indoor walls. Herein we report that surfaces coated with photocatalytic composites exhibit
excellent antimicrobial properties by killing both methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) under blue light. In the case of MSSA cells, the
palladium nanoparticle-decorated and nitrogen-doped TiO2 composites demonstrated the highest
antimicrobial activity. For the MRSA strain even pure gypsum samples were proven to be efficient in
eradicating Gram-positive human pathogens. The cytotoxicity of freestanding TiO2 nanofibers was
revealed by analyzing the viability of HeLa cells using MTT and fluorescent cell assays.