Prismatic Silver Nanoparticles Decorated on Graphene Oxide Sheets for Superior Antibacterial Activity

Abstract

Spherical silver nanoparticles (Ag NPs) and silver nanoprisms (Ag NPrsms) were synthesized and decorated on graphene oxide (GO) nanosheets. The Ag contents were 29% and 23% in the GO–Ag NPs and GO–Ag NPrsms, respectively. The Ag NPrsms exhibited stronger (111) crystal signal than Ag NPs. The GO–Ag NPrsms exhibited higher Ag (I) content (75.6%) than GO-Ag NPs (69.9%). Increasing the nanomaterial concentration from 25 to 100 µg mL−1 improved the bactericidal efficiency, and the antibacterial potency was in the order: GO–Ag NPrsms > GO–Ag NPs > Ag NPrsms > Ag NPs > GO. Gram-positive Staphylococcus aureus (S. aureus) was more vulnerable than Gram-negative Escherichia coli (E. coli) upon exposure to these nanomaterials. The GO–Ag NPrsms demonstrated a complete (100%) bactericidal effect against S. aureus at a concentration of 100 µg mL−1. The GO–Ag composites outperformed those of Ag or GO due to the synergistic effect of bacteriostatic Ag particles and GO affinity toward bacteria. The levels of reactive oxygen species produced in the bacteria–nanomaterial mixtures were highly correlated to the antibacterial efficacy values. The GO–Ag NPrsms are promising as bactericidal agents to suppress biofilm formation and inhibit bacterial infection.

Mesoporous Ag-functionalized magnetic activated carbon-based agro-waste for efficient removal of Pb(II), Cd(II), and microorganisms from wastewater

“…Table 5 also displays the antibacterial activities of some other reported studies. It can be remarked that the values of the inhibition zones of Mag@AC1-Ag and Mag@AC2-Ag were smaller than those obtained by Truong et al (2022) and Altintig et al (2022) for gram-positive bacteria but higher for gram-negative bacteria. On the other hand, they were higher than the other materials for both strains, demonstrating the effectiveness of Mag@AC1-Ag and Mag@AC2-Ag as antibacterial materials.…”

Engineering the surface of titanium to improve its bioactivity and antibacterial activity through a multi-functional coating approach

“…48 Other researchers have also observed a larger inhibition zone of 22 mm and 33 mm for silver nanoparticle decorated GO nanosheets when compared to pure silver nanoparticles and pure GO. 49,50…”

“…48 Other researchers have also observed a larger inhibition zone of 22 mm and 33 mm for silver nanoparticle decorated GO nanosheets when compared to pure silver nanoparticles and pure GO. 49,50 Among the two strains of bacteria, E. coli showed a higher resistance to Ag + ions, AgNPs, GO and AgrGO than S. aureus due to the presence of a thick peptidoglycan layer of Gram positive bacteria that limits the antibacterial action through the bacterial cell wall. When compared with the others, the AgBG-rGO/PCL composite coating showed a lower inhibitory effect to both S. aureus and E. coli due to the decrease in oxygen functional groups of rGO, which reduced the lipid peroxidation process.…”

Recent advances and mechanism of antimicrobial efficacy of graphene-based materials: a review

“…GNCs of metal ions/sulphides/oxides and nanoparticles such as cadmium sulphide (CdS), titanium dioxide (TiO2), and zinc oxide (ZnO) have been shown by multiple research groups to have antibacterial activity with the formation of ROS via photocatalytic process when exposed to light with an energy larger than their band gap. These metal oxides and sulphides act as a photocatalyst to generate ROS to kill bacterial [ 80 , 125 , 126 ]. Furthermore, Panda and coworkers suggest that the antibacterial action of naturally produced GO-metal films is caused by the concomitant effect of both the non-oxidative electrons transfer mechanism and the consequent formation of ROS in the exposed bacteria [ 99 ].…”

“…aureus cells treated with different nanocomposites was demonstrated by fluorescence imaging of the treated cell stained with DCFH-DA (2′,7′-dichlorofluorescein diacetate) stain (Fig. 10I and II ) [ 87 , 125 ].

Figure 10 Determination of oxidative stress induced by graphene materials.

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