Antibacterial applications of graphene-based nanomaterials: Recent achievements and challenges.

Assessment of the toxic potential of graphene family nanomaterials

Perspective and status of polymeric graphitic carbon nitride based Z-scheme photocatalytic systems for sustainable photocatalytic water purification

Nanotechnology has revolutionized almost all the fields of science and technology, particularly the food packaging industry Accordingly, some nanoparticles can be used in food contact materials to preserve food products for longer periods To date, many inorganic and metal nanoparticles have been implemented to synthesize active food packaging materials and to extend the shelf-life of foods Packaging with nanocomposites containing these nanoparticles offers advantages, such as reduction in the usage of preservatives and higher rate of reactions to inhibit the microbial growth Nevertheless, the safety issues of employing the metal and inorganic nanoparticles in food packaging are still a major concern and more studies along with clinical trials need to be carried out prior to the mass production of these promising food containers In this review, we have evaluated recent studies plus the applications of inorganic and metal nanoparticles mostly in food packaging applications along with their antimicrobial properties and reaction mechanisms Many examples have been provided with the aim of opening new horizons for researchers to implement inorganic and metal nanoparticles in active food packaging field

Inorganic and metal nanoparticles and their antimicrobial activity in food packaging applications

Physicochemical properties of gelatin/silver nanoparticle antimicrobial composite films

A highly homogeneous ZnO/Ag nanohybrid has been synthesized by a novel route, employing chitosan as mediator by purely electrostatic interaction. By employing various techniques such as powder XRD, UV-visible, IR spectroscopy and electron (SEM, TEM) microscopy, the formation of the nanohybrid has been established. The synergistic antibacterial effect of ZnO/Ag nanohybrid on Gram-positive and Gram-negative bacteria is found to be more effective, compared to the individual components (ZnO and Ag). Cytotoxicity experiments are carried out and the results are correlated to the solubility of the nanohybrid. A possible mechanism has been proposed for the antibacterial activity of ZnO/Ag nanohybrid, based on TEM studies on bacteria, carried out by employing the microtome technique and by EPR measurements on the hybrid.

ZnO/Ag nanohybrid: synthesis, characterization, synergistic antibacterial activity and its mechanism

Antimicrobial activity of highly stable silver nanoparticles embedded in agar-agar matrix as a thin film.

A novel in situ core@shell structure consisting of nanoparticles of Ag (Ag Nps) and AgI in agarose matrix (Ag@ AgI/agarose) has been synthesized as a hybrid, in order to have an efficient antibacterial agent for repetitive usage with no toxicity. The synthesized core@shell structure is very well characterized by XRD, UV-visible, photoluminescence, and TEM. A detailed antibacterial studies including repetitive cycles are carried out on Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria in saline water, both in dark and on exposure to visible light. The hybrid could be recycled for the antibacterial activity and is nontoxic toward human cervical cancer cells (HeLa cells). The water insoluble Ag@AgI in agarose matrix forms a good coating on quartz, having good mechanical strength. EPR and TEM studies are carried out on the Ag@AgI/agarose and the bacteria, respectively, to elucidate a possible mechanism for killing of the bacteria.

Ag@AgI, Core@Shell Structure in Agarose Matrix as Hybrid: Synthesis, Characterization, and Antimicrobial Activity

Antibacterial efficacy of silver nanoparticles (Ag NPs) deposited alternatively layer by layer (LBL) on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip has been studied. An eight-bilayer chitosan/silver (Cs/Ag)8 hybrid was prepared having a known concentration of silver. Techniques such as UV-visible spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), and atomic force microscopy (AFM) were carried out to understand and elucidate the physical nature of the film. Gram-negative bacteria, Escherichia coli (E. coli), were used as a test sample in saline solution for antibacterial studies. The growth inhibition at different intervals of contact time and, more importantly, the antibacterial properties of the hybrid film on repeated cycling in saline solution have been demonstrated. AFM studies are carried out for the first time on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months) are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. The hybrid can be a promising bioactive material for the prevention of biofilms specific to E. coli and in purification of water for safe drinking.

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Study of Antibacterial Efficacy of Hybrid Chitosan-Silver Nanoparticles for Prevention of Specific Biofilm and Water Purification

A porous carbon foam (CF) electrode modified with a reduced graphene oxide-Ag (rGO-Ag) nanocomposite has been fabricated to purify water. It can perform as an antibacterial device by killing pathogenic microbes with the aid of a 1.5 V battery, with very little power consumption. The device is recycled ten times with good performance for long term usage. It is shown that the device may be implemented as a fast water purifier to deactivate the pathogens in drinking water.

https://iopscience.iop.org/article/10.1088/0957-4484/24/23/235101/pdf

H. N. Vasan

Papers

ZnO/Ag nanohybrid: synthesis, characterization, synergistic antibacterial activity and its mechanism

Antimicrobial activity of highly stable silver nanoparticles embedded in agar-agar matrix as a thin film.

Ag@AgI, Core@Shell Structure in Agarose Matrix as Hybrid: Synthesis, Characterization, and Antimicrobial Activity

Study of Antibacterial Efficacy of Hybrid Chitosan-Silver Nanoparticles for Prevention of Specific Biofilm and Water Purification

1.5 V battery driven reduced graphene oxide?silver nanostructure coated carbon foam (rGO?Ag?CF) for the purification of drinking water