Graphene nanomaterials have received great attention in the last few years due to their interesting properties. Recent studies reported their significant activity against bacterial infections. The surface functionalization effect on the antibacterial activity has yet to be elucidated. Moreover, graphene suffered from low water dispersibility. Herein, for the first time, various covalent functionalization was applied on the surface of graphene sheet in order to improve its water dispersibility and study its effect on the antibacterial behavior and mechanism of toxicity. The three functionalized graphene sheets (graphene-TEG-OH, graphene-DEG-COOH and graphene-NH₂) demonstrated good water dispersibility as confirmed by transmission electron microscope images, infrared spectra and thermogravimitric analysis. More interestingly, the antibacterial activity of the functionalized graphene (f-graphene) nanomaterials against S. auerus and E. coli was improved significantly in comparison to the graphene sheets alone as confirmed by agar diffusion disk, microdilution method and the reduction of the colony forming unit. The minimum inhibitory concentration  (MIC) of the graphene derivatives showing MIC of 250 µg/ml for graphene-TEG-OH and graphene-NH₂ and a125 µg/ml in the case of graphene-DEG-COOH. Moreover, the reduction of bacterial growth was increased in f-graphene nanomaterials with the complete inhibition in the case of graphene-DEG-COOH on both bacteria. Graphene toxicity mechanism was investigated by in vitro graphene-mediated oxidation of glutathione, the loss of glutathione activity was the maximum for graphene-DEG-COOH with a reduction of 83%. Finally, graphene-DEG-COOH and graphene-TEG-OH showed good hemocompatibility which supports their further in vivo studies.

Conference Title

sixth international conference on multifunctional, hybrid and nanomaterials

Conference Country

Spain

Conference Date

March 11, 2019 - March 15, 2019

Conference Sponsor

Elsevier