Graphene Oxide Sheets Decorated with Octahedral Molybdenum Cluster Complexes for Enhanced Photoinactivation of Staphylococcus aureus

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.

Automated summary

The photoinactivation of pathogenic bacteria using materials generating reactive oxygen species upon exposure to visible light can overcome the challenge of multidrug-resistant microbial pathogens. A nanocomposite material consisting of graphene oxide sheets adorned with nanoaggregates of octahedral molybdenum cluster complexes has been developed. The electrostatic interaction and close cohesion between the components in aqueous medium contributed to the potent antibacterial effect against Staphylococcus aureus upon illumination with blue light. The photoinduced electron transfer from the nanoaggregates to the graphene oxide sheets triggers the generation of reactive oxygen species, making graphene oxide and light-harvesting octahedral molybdenum cluster complexes promising for effective antibacterial strategies.