Surface deposited one-dimensional copper-doped TiO₂ nanomaterials for prevention of health care acquired infections

<div><p>Bacterial infections acquired in healthcare facilities including hospitals, the so called healthcare acquired or nosocomial infections, are still of great concern worldwide and represent a significant economical burden. One of the major causes of morbidity is infection with <i>Methicillin Resistant Staphylococcus aureus</i> (MRSA), which has been reported to survive on surfaces for several months. Bactericidal activity of copper-TiO₂ thin films, which release copper ions and are deposited on glass surfaces and heated to high temperatures, is well known even when illuminated with very weak UVA light of about 10 μW/cm². Lately, there is an increased intrerest for one-dimensional TiO₂ nanomaterials, due to their unique properties, low cost, and high thermal and photochemical stability. Here we show that copper doped TiO₂ nanotubes produce about five times more ·OH radicals as compared to undoped TiO₂ nanotubes and that effective surface disinfection, determined by a modified ISO 22196:2011 test, can be achieved even at low intensity UVA light of 30 μW/cm². The nanotubes can be deposited on a preformed surface at room temperature, resulting in a stable deposition resistant to multiple washings. Up to 10³ microorganisms per cm² can be inactivated in 24 hours, including resistant strains such as <i>Methicillin-resistant Staphylococcus aureus</i> (MRSA) and <i>Extended-spectrum beta-lactamase Escherichia coli</i> (<i>E</i>. <i>coli</i> ESBL). This disinfection method could provide a valuable alternative to the current surface disinfection methods.</p>