New photosensitive nanometric graphite oxide composites as antimicrobial material with prolonged action

• New nanomaterial based on graphite oxide was obtained.
• Photoactivity enhanced by including of Zr-phthalocyanine complex and silver nanoparticles.
• The structure, morphology and optical properties of composite were investigated.
• Antibacterial photoactivity against S. aureus, P. aeruginosa, and E. coli was presented.
• Potential use of obtained composite as antibacterial agent with prolonged action was rated.

A new conjugate material based on partially reduced graphite oxide (rGO), silver nanoparticles (Ag), and bis(lysinato)zirconium(IV) phthalocyanine complex (ZrPc) was obtained. Its optical properties (absorption and photoluminescence) after dispersion in solvents were examined. The antimicrobial properties were tested to determine the effect of the composite on the following bacterial strains: Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, which are responsible for many infections and are one of the pathogens the most difficult to treatment. The results obtained for rGO–ZrPc–Ag composite were compared with the properties of GO, GO–ZrPc, and rGO–Ag structures. The influence of the near-infrared irradiation on the antimicrobial activity of ZrPc- and Ag-doped materials against bacteria was observed for very low concentration (0.32 mg/mL) of GO–ZrPc to stop the growth of P. aeruginosa in comparison to the nonirradiated sample (41 mg/mL). The usefulness of this material in therapy, such as wound infection treatment or endodontic treatment, as antibacterial agent with sustained action was discussed.

With infrared irradiation, the graphite oxide based composite materials, doped with zirconium phthalocyanine and silver nanoparticles, is characterized by high antimicrobial activity at very low concentration. Such materials may be good bactericidal agents (eq. as additive for endodontic fillings) due to lack of facilities to develop antimicrobial resistance.Figure optionsDownload as PowerPoint slide