Graphene Oxide–Silver Nanoparticle Nanohybrids: Synthesis, Characterization, and Antimicrobial Properties

Abstract

Drug resistance of pathogenic microorganisms has become a global public health problem, which has prompted the development of new materials with antimicrobial properties. In this context, antimicrobial nanohybrids are an alternative due to their synergistic properties. In this study, we used an environmentally friendly one-step approach to synthesize graphene oxide (GO) decorated with silver nanoparticles (GO–AgNPs). By this process, spherical AgNPs of average size less than 4 nm homogeneously distributed on the surface of the partially reduced GO can be generated in the absence of any stabilizing agent, only with ascorbic acid (L-AA) as a reducing agent and AgNO3 as a metal precursor. The size of the AgNPs can be controlled by the AgNO3 concentration and temperature. Smaller AgNPs are obtained at lower concentrations of the silver precursor and lower temperatures. The antimicrobial properties of nanohybrids against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, Gram-positive Staphylococcus aureus, and the yeast Candida albicans were found to be concentration- and time-dependent. C. albicans and S. aureus showed the highest susceptibility to GO–AgNPs. These nanohybrids can be used as nanofillers in polymer nanocomposites to develop materials with antimicrobial activity for applications in different areas, and another potential application could be cancer therapeutic agents.

Antibacterial Action of Nanoparticle Loaded Nanocomposites Based on Graphene and Its Derivatives: A Mini-Review

“…Thus, the antibacterial efficacy of AgNP-GO with four NP sizes (10, 30, 50, and 80 nm) against E. coli and S. aureus has been tested, and its was found that the composite with the smallest NP showed the best activity [61]. Similarly, a recent study [62] investigated the bactericide action of AgNP-GO (ratio 1:2.3) manufactured via an environmentally friendly one-step approach, which comprised of spherical NPs with different diameters. The smallest NPs (ca.…”

“…To solve this issue, nanocomposites of graphene and Ag nanoparticles were developed [49,50], although the improvements in antibacterial activity were still limited. Therefore, numerous studies have been reported on GO and rGO nanocomposites comprising Ag nanoparticles [51][52][53][54][55][56][57][58][59][60][61][62] (Table 1), showing improved performance compared to GO and Ag nanoparticles alone due to synergistic effects; further, the mixture of both constituents considerably reduces the concentrations required to inhibit all bacteria. Thus, significantly higher antibacterial activity was found for AgNPs-GO composites (1:2 ratio), with an average NP size of 80 nm [52] at a concentration of 200 µg/mL (Table 1), compared to that of GO or AgNPs, attributed to a higher ROS production, hence resulting in stronger oxidative stress and disruption of the cell membrane.…”

Synthesis, Physical, Mechanical and Antibacterial Properties of Nanocomposites Based on Poly(vinyl alcohol)/Graphene Oxide–Silver Nanoparticles

“…Details of the synthesis are described in the Supplementary Materials (Preparation of Graphene Oxide (GO)). We used the in situ approach for the synthesis of GO-AgNPs hybrid, which consists of simultaneous reduction of metal salt and GO using L-AA as a green reductant as described in our previous work [42]. Briefly, an aqueous dispersion of graphite oxide (GrO) (0.5 mg/mL) was sonicated for 1 h to obtain GO.…”

Antibacterial Character of Cationic Polymers Attached to Carbon-Based Nanomaterials

“…Graphene and its derivative materials have relatively high specific surface area with abundant surface functionalities in case of graphene oxide, which have the potential for the preparation of multiple composite antibacterial materials in combination with other antimicrobial agents [20,21]. It has been proved the synergistic or additive effect of graphene derivatives with silver composite materials, leading an enhanced activity at low concentration [22][23][24][25]. Similarly, hybrid systems with ZnO and TiO 2 nanoparticles have demonstrated excellent antibacterial activity [26][27][28].…”