Korean J Dent Mater.  2020 Jun;47(2):93-104. 10.14815/kjdm.2020.47.2.93.

Diffuse reflection characterization and visible light mediated antibacterial effect of Pt-TiO2 nanotubes

• Moon KS
• Bae JM
• Oh S

• KMID: 2504116
• DOI: http://doi.org/10.14815/kjdm.2020.47.2.93

Abstract

The purpose of this study was to fabricate platinum (Pt), one of the plasmonic nanoparticles that induces localized surface plasmon resonance (LSPR) effects caused by the pairing of plasmon with the electric field of visible-near infrared light, coated 100 nm titania (Pt-TiO₂) nanotubes to evaluate the surface properties and laser mediated antibacterial effects. From the analysis of UV-VIS-NIR spectrum, the light absorptions of Pt-TiO₂ nanotubes were detected at wavelengths 399–429 nm, 527–579 nm, and 806–906 nm, respectively, and one of the detected wavelengths was suitable for the laser used in this study (OCLA, Wavelength: 405). From the observation of FE-SEM, as the platinum coating time increased, the inner diameter of the Pt-TiO₂ nanotubes decreased from 68.8 nm to 48.8 nm, and the shape of the platinum nanoparticles coated on the top layer of the titania nanotubes changed from spherical to rod. From the results of contact angle measurement, the contact angle of water increased from 11.94°to 19.84°as the platinum coating time increased from 1 minute to 3 minutes. The Staphylococcus aureus antibacterial test resulted that 98% or more bacterial reduction of all Pt-TiO₂ nanotube groups were observed after laser irradiation (P<0.05). Live-dead assay and MTT assay indicated that laser irradiation did not affect cell death. Therefore, Pt–TiO₂ nanotube exhibiting a local surface plasmon resonance effect is expected to have many potentials for semi-permanent antimicrobial implant surface treatment without antibacterial drugs.

Keyword

Platinum; Titania nanotube; Laser; Antibacterial effect