The emergence of multidrug-resistant microbial pathogens poses a significant threat, severely limiting the options for effective antibiotic therapy. This challenge can be overcome through the photoinactivation of pathogenic bacteria using materials generating reactive oxygen species upon exposure to visible light. These species target vital components of living cells, significantly reducing the likelihood of resistance development by the targeted pathogens. In our research, we have developed a nanocomposite material consisting of an aqueous colloidal suspension of graphene oxide sheets adorned with nanoaggregates of octahedral molybdenum cluster complexes. The negative charge of the graphene oxide and the positive charge of the nanoaggregates promoted their electrostatic interaction in aqueous medium and close cohesion between the colloids. Upon illumination with blue light, the colloidal system exerted a potent antibacterial effect against planktonic cultures of Staphylococcus aureus largely surpassing the individual contributions of the components. The underlying mechanism behind this phenomenon lies in the photoinduced electron transfer from the nanoaggregates of the cluster complexes to the graphene oxide sheets, which triggers the generation of reactive oxygen species. Thus, leveraging the unique properties of graphene oxide and light-harvesting octahedral molybdenum cluster complexes can open more effective and resilient antibacterial strategies.

• MeSH
• antibakteriální látky farmakologie   MeSH
• lidé MeSH
• molybden farmakologie   MeSH
• reaktivní formy kyslíku MeSH
• stafylokokové infekce * MeSH
• Staphylococcus aureus * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• graphene oxide MeSH Prohlížeč
• molybden MeSH
• reaktivní formy kyslíku MeSH

The fight against infective microorganisms is becoming a worldwide priority due to serious concerns about the rising numbers of drug-resistant pathogenic bacteria. In this context, the inactivation of pathogens by singlet oxygen, O2(1Δg), produced by photosensitizers upon light irradiation has become an attractive strategy to combat drug-resistant microbes. To achieve this goal, we electrophoretically deposited O2(1Δg)-photosensitizing octahedral molybdenum cluster complexes on indium-tin oxide-coated glass plates. This procedure led to the first example of molecular photosensitizer layers able to photoinactivate bacterial biofilms. We delineated the morphology, composition, luminescence, and singlet oxygen formation of these layers and correlated these features with their antibacterial activity. Clearly, continuous 460 nm light irradiation imparted the layers with strong antibacterial properties, and the activity of these layers inhibited the biofilm formation and eradicated mature biofilms of Gram-positive Staphylococcus aureus and Enterococcus faecalis, as well as, Gram-negative Pseudomonas aeruginosa and Escherichia coli bacterial strains. Overall, the microstructure-related oxygen diffusivity of the layers and the water stability of the complexes were the most critical parameters for the efficient and durable use. These photoactive layers are attractive for the design of antibacterial surfaces activated by visible light and include additional functionalities such as the conversion of harmful UV/blue light to red light or oxygen sensing.

• Klíčová slova
• biofilm, electrophoretic deposition, luminescence, molybdenum cluster complex, phototoxicity, singlet oxygen,
• MeSH
• biofilmy účinky léků   MeSH
• Enterococcus faecalis fyziologie   MeSH
• Escherichia coli fyziologie   MeSH
• fotosenzibilizující látky chemie   farmakologie   MeSH
• komplexní sloučeniny chemie   farmakologie   MeSH
• molybden chemie   MeSH
• singletový kyslík chemie   metabolismus   MeSH
• sklo chemie   MeSH
• Staphylococcus aureus fyziologie   MeSH
• světlo * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fotosenzibilizující látky MeSH
• komplexní sloučeniny MeSH
• molybden MeSH
• singletový kyslík MeSH