Molybdenum Nanoclusters-Functionalized Porous TiO ₂ Inverse Opal Layers for Light-Activated Inhibition of S. aureus Biofilms

High Resolution Image Download MS PowerPoint Slide The rise of persistent, antibiotic-resistant infections driven by Staphylococcus aureus biofilms necessitates the development of innovative antibiofilm strategies. This study introduces a hybrid photocatalytic platform composed of a porous titanium dioxide (TiO 2 ) inverse opal layer doped with molybdenum nanoclusters (Mo 6 ). The nanostructured TiO 2 layer allows for the electrophoretic deposition of Mo 6 in the form of submicrometer-sized aggregates. Spectroscopic analysis revealed a dual mechanism where, upon excitation, Mo 6 generate singlet oxygen, O 2 ( 1 Δ g ), or undergo photoinduced electron transfer to the TiO 2 matrix, leading to amplified production of hydroxyl radicals. Consequently, under 405 nm irradiation, Mo 6 @TiO 2 layers demonstrated inhibition of S. aureus biofilm formation, reducing viable cells by over 3 orders of magnitude, whereas bare TiO 2 showed a negligible activity. Moreover, the Mo 6 @TiO 2 platform maintained its high performance upon reuse. These findings establish Mo 6 -functionalized TiO 2 inverse opal layers as robust, light-activated, and recyclable antibiofilm surfaces with significant potential for biomedical applications.