TiO2 in the form of nanocrystals possesses photocatalyst properties leading to excellent capability of degrading a number of environmental contaminants such as organics, bacteria, and viruses. However, the antimicrobial activity of nano-TiO2 coatings against different microorganisms is not yet well established. Candida albicans, Aspergillus niger, Staphylococcus aureus and Streptococcus mutans are common nosocomial and environmental pathogens responsible for biofilm-associated infections especially in indoor environments. In this study, we produced thin coatings of TiO2 nanoparticles on aluminum substrates and assessed whether they may prevent fungi and bacteria biofilm formation and whether this may be a synergistic effect of TiO2 nanoparticles with UV irradiation, which is more representative of the natural conditions for passive devices. Coatings of flame-synthesized nanoparticles were produced by direct thermophoretic deposition on aluminum substrates through a rotating disk inserted in the flame. Particle and coating characterization was performed by means of differential mobility analysis, Raman and X-ray diffraction spectroscopy. Microbial biofilm formation on substrates with different TiO2 thicknesses were evaluated by the colorimetric crystal violet method and quantified by spectrophotometry in four different fungi and bacteria strains; the results were corroborated by scanning electron microscopy analysis. Substrates with minimal TiO2 nanoparticle layers demonstrated a strong anti-biofilm effect against both fungi and bacteria, due to the well-known cellular component photo-oxidation and to the enhanced nanomaterial surface area. Interestingly, UV irradiation of the substrates at a low intensity for a short time demonstrated a significant enhancement of the titania antimicrobial activity. TiO2 nanoparticle coatings may be proposed as self-cleaning and self-disinfecting materials able to reduce microbial infections, especially in indoor environments where hygiene is needed.

Antimicrobial activity of flame-synthesized nano-TiO2 coatings

PORTA, AMALIA;PETRONE, ANNA MARIA;DEL GAUDIO, Pasquale;
2017-01-01

Abstract

TiO2 in the form of nanocrystals possesses photocatalyst properties leading to excellent capability of degrading a number of environmental contaminants such as organics, bacteria, and viruses. However, the antimicrobial activity of nano-TiO2 coatings against different microorganisms is not yet well established. Candida albicans, Aspergillus niger, Staphylococcus aureus and Streptococcus mutans are common nosocomial and environmental pathogens responsible for biofilm-associated infections especially in indoor environments. In this study, we produced thin coatings of TiO2 nanoparticles on aluminum substrates and assessed whether they may prevent fungi and bacteria biofilm formation and whether this may be a synergistic effect of TiO2 nanoparticles with UV irradiation, which is more representative of the natural conditions for passive devices. Coatings of flame-synthesized nanoparticles were produced by direct thermophoretic deposition on aluminum substrates through a rotating disk inserted in the flame. Particle and coating characterization was performed by means of differential mobility analysis, Raman and X-ray diffraction spectroscopy. Microbial biofilm formation on substrates with different TiO2 thicknesses were evaluated by the colorimetric crystal violet method and quantified by spectrophotometry in four different fungi and bacteria strains; the results were corroborated by scanning electron microscopy analysis. Substrates with minimal TiO2 nanoparticle layers demonstrated a strong anti-biofilm effect against both fungi and bacteria, due to the well-known cellular component photo-oxidation and to the enhanced nanomaterial surface area. Interestingly, UV irradiation of the substrates at a low intensity for a short time demonstrated a significant enhancement of the titania antimicrobial activity. TiO2 nanoparticle coatings may be proposed as self-cleaning and self-disinfecting materials able to reduce microbial infections, especially in indoor environments where hygiene is needed.
File in questo prodotto:
File Dimensione Formato  
Antimicrobial Activity of Flame-Synthesized Nano-TiO2 Coatings.pdf

non disponibili

Tipologia: Documento in Post-print (versione successiva alla peer review e accettata per la pubblicazione)
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 5.38 MB
Formato Adobe PDF
5.38 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/4686527
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 42
  • ???jsp.display-item.citation.isi??? 38
social impact