Visible-light-activated antibacterial and antipollutant properties of biocompatible Cu-doped and Ag-decorated TiO2 nanoparticles
Panagiotis Tzevelekidis,
Maria Theodosiou,
Athina Papadopoulou,
Elias Sakellis,
Nikos Boukos,
Alexandros K. Bikogiannakis,
Georgios Kyriakou,
Eleni K. Efthimiadou,
Christiana A. Mitsopoulou
Affiliations
Panagiotis Tzevelekidis
Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece
Maria Theodosiou
Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece; Institute of Nanoscience and Nanotechnology, National Center of Scientific Research “Demokritos”, Agia Paraskevi, 15341, Greece
Athina Papadopoulou
Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece; Institute of Nanoscience and Nanotechnology, National Center of Scientific Research “Demokritos”, Agia Paraskevi, 15341, Greece
Elias Sakellis
Institute of Nanoscience and Nanotechnology, National Center of Scientific Research “Demokritos”, Agia Paraskevi, 15341, Greece; Section of Condensed Matter Physics, Department of Physics, National and Kapodistrian University of Athens, Athens, 15784, Greece
Nikos Boukos
Institute of Nanoscience and Nanotechnology, National Center of Scientific Research “Demokritos”, Agia Paraskevi, 15341, Greece
Alexandros K. Bikogiannakis
Department of Chemical Engineering, University of Patras, Caratheodory 1, Patras, 26504, Greece
Georgios Kyriakou
Department of Chemical Engineering, University of Patras, Caratheodory 1, Patras, 26504, Greece
Eleni K. Efthimiadou
Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece; Corresponding author.
Christiana A. Mitsopoulou
Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece; Corresponding author.
Optical and photocatalytic restrictions of anatase TiO2 nanoparticles (Nps) limit their potential applications, as antipollutant and antibacterial agents for sanitary applications, to the UV spectral region. While modification with transition metals extends the absorption capacity to the visible light spectrum, often undermines the photocatalysts' biocompatibility due to toxic ion leaching. In this study, we synthesized Cu-doped and Ag-decorated TiO2 photocatalysts by employing solvothermal (ATiO2:Cu) and sol-gel synthetic procedures (BTiO2:Ag), respectively. We acquired TiO2 Nps modified with three percentages of either Cu or Ag content, to examine the potential differentiation of their structural, photocatalytic, and biological impact. Comprehensive structural characterization supports the prevailing anatase crystalline structure of bare and modified titania nanostructures, while morphological differences are demonstrated among the different samples. Optical response in the visible region of ATiO2:Cu Nps stems from band gap narrowing and lattice-defect generation, while plasmonic effects are at play for BTiO2:Ag Nps. Their photocatalytic potential under visible light irradiation, originated from low-energy LED lamps commonly found in indoor spaces, was verified after monitoring the successful enhancement of methylene blue (MB) degradation rate. Safety assessment on immortalized healthy human keratinocyte cell line (HaCaT) revealed their biocompatibility up to a certain concentration, while reactive oxygen species (ROS) production was intensified after light irradiation. The visible-light-induced photocatalytic-driven antibacterial activity was confirmed against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli.
