Visible Light Irradiation-Mediated Drug Elution Activity of Nitrogen-Doped TiO2Nanotubes

We have developed nitrogen-doped [subscript] TiO 2[/subscript] nanotubes showing photocatalytic activity in the visible light region and have investigated the triggered release of antibiotics from these nanotubes in response to remote visible light irradiation. Scanning electron microscopy (SEM) observations indicated that the structure of [subscript] TiO 2[/subscript] nanotubes was not destroyed on the conditions of 0.05 and 0.1 M diethanolamine treatment. The results of X-ray photoelectron spectroscopy (XPS) confirmed that nitrogen, in the forms of nitrite ( [superscript] [subscript] NO 2[/subscript] -[/superscript] ) and nitrogen monoxide (NO), had been incorporated into the [subscript] TiO 2[/subscript] nanotube surface. A drug-release test revealed that the antibiotic-loaded [subscript] TiO 2[/subscript] nanotubes showed sustained and prolonged drug elution with the help of polylactic acid. Visible light irradiation tests showed that the antibiotic release from nitrogen-doped [subscript] TiO 2[/subscript] nanotubes was significantly higher than that from pure [subscript] TiO 2[/subscript] nanotubes ( P