Synergic bactericidal effects of reduced graphene oxide and silver nanoparticles against Gram-positive and Gram-negative bacteria

Abstract

Reduced graphene oxide (rGO) is a promising antibacterial material, the efficacy of which can be further enhanced by the addition of silver nanoparticles (nAg). In this study, the mechanisms of antibacterial activity of rGO–nAg nanocomposite against several important human pathogenic multi-drug resistant bacteria, namely Gram-positive coccal Staphylococcus aureus and Gram-negative rod-shaped Escherichia coli and Proteus mirabilis are investigated. At the same concentration (100 µg/ml), rGO–nAg nanocomposite was significantly more effective against all three pathogens than either rGO or nAg. The nanocomposite was equally active against P. mirabilis and S. aureus as systemic antibiotic nitrofurantoin, and significantly more effective against E. coli. Importantly, the inhibition was much faster in the case of rGO–nAg nanocomposite compared to nitrofurantoin, attributed to the synergistic effects of rGO–nAg mediated contact killing and oxidative stress. This study may provide new insights for the better understanding of antibacterial actions of rGO–nAg nanocomposite and for the better designing of graphene-based antibiotics or other biomedical applications.

Nanoengineered Antibacterial Coatings and Materials: A Perspective

“…Recently, we discovered that ultra-small 1-2 nm silver (and gold) nanoparticles synthesised in an aqueous medium have a very high potency against a range of clinically relevant pathogens, but also reduce expression of pro-inflammatory cytokines from immune cells and help wounds to close [88][89][90]. We also combined silver nanoparticles and graphene oxide nanostructures and demonstrated a synergic bactericidal effect against Gram-positive and Gram-negative bacteria [81]. Figure 2), while the AgNPs release silver ions to eliminate bacteria in the vicinity of the substrate.…”

Recent developments in nanotechnology transforming the agricultural sector: a transition replete with opportunities

“…Both the Ag‐ and Cu‐based monometallic graphene composites were reported to suppress bacterial growth, in particular, Ag‐based graphene composite showed higher antibacterial activity as compared to the Cu‐based graphene composite . Recently, several important multi‐drug resistant bacteria have been successfully treated by using the antibacterial activity of reduced graphene‐silver nanocomposite . The development of recyclable and synergistic graphene oxide nanocomposite was reported by using both silver nanoparticles and iron oxide nanoparticles as a novel multifunctional antibacterial material …”

“…126 Recently, several important multi-drug resistant bacteria have been successfully treated by using the antibacterial activity of reduced graphene-silver nanocomposite. 127 The development of recyclable and synergistic graphene oxide nanocomposite was reported by using both silver nanoparticles and iron oxide nanoparticles as a novel multifunctional antibacterial material. 128 Numerous studies have confirmed that metal nanoparticles are effective against plant pathogens, pests and insects and, therefore, the topic is deserving of extended discussion.…”

Hierarchical Multicomponent Inorganic Metamaterials: Intrinsically Driven Self‐Assembly at the Nanoscale

“…Unlike B. subtilis , the rate of colonization by E. coli was not affected by plasma treatment. On surfaces with sharp nanoscale features, contact killing of cells through mechanical deformation of the membrane can take place . Generally, Gram‐negative bacteria, such as E. coli , have cell walls that are more susceptible to carbon‐nanotube‐induced morphological deformation than those of the Gram‐positive strains, e.g., B. subtilis .…”