The antimicrobial impact of biogenic-synthesized silver-based nanoparticles has been the focus of increasing interest. As the antimicrobial activity of nanoparticles is highly dependent on their size and surface, the complete and adequate characterization of the nanoparticle is important. This review discusses the characterization and antimicrobial activity of biogenic synthesized silver nanoparticles and silver chloride nanoparticles. By revising the literature, there is confusion in the characterization of these two silver-based nanoparticles, which consequently affects the conclusion regarding to their antimicrobial activities. This review critically analyzes recent publications on the synthesis of biogenic silver nanoparticles and silver chloride nanoparticles by attempting to correlate the characterization of the nanoparticles with their antimicrobial activity. It was difficult to correlate the size of biogenic nanoparticles with their antimicrobial activity, since different techniques are employed for the characterization. Biogenic synthesized silver-based nanoparticles are not completely characterized, particularly the nature of capped proteins covering the nanomaterials. Moreover, the antimicrobial activity of theses nanoparticles is assayed by using different protocols and strains, which difficult the comparison among the published papers. It is important to select some bacteria as standards, by following international foundations (Pharmaceutical Microbiology Manual) and use the minimal inhibitory concentration by broth microdilution assays from Clinical and Laboratory Standards Institute, which is the most common assay used in antibiotic ones. Therefore, we conclude that to have relevant results on antimicrobial effects of biogenic silver-based nanoparticles, it is necessary to have a complete and adequate characterization of these nanostructures, followed by standard methodology in microbiology protocols.

Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments

This review is devoted to the medical application of silver nanoparticles produced as a result of “green” synthesis using various living organisms (bacteria, fungi, plants). The proposed mechanisms of AgNPs synthesis and the action mechanisms on target cells are highlighted.

https://www.mdpi.com/2079-4983/11/4/84/pdf

Silver Nanoparticles: Mechanism of Action and Probable Bio-Application

Phytochemical-assisted synthetic approaches for silver nanoparticles antimicrobial applications: A review.

The present investigation reports utility of cocoa pod husk extract (CPHE), an agro-waste in the biosynthesis of silver nanoparticles (AgNPs) under ambient condition. The synthesized CPHE-AgNPs were characterized by UV–visible spectroscopy, Fourier-transform infrared spectroscopy, Energy dispersive X-ray (EDX) spectroscopy and transmission electron microscopy. The feasibility of the CPHE-AgNPs as antimicrobial agent against some multidrug-resistant clinical isolates, paint additive, and their antioxidant and larvicidal activities were evaluated. CPHE-AgNPs were predominantly spherical (size range of 4–32 nm) with face-centered cubic phase and crystalline conformation pattern revealed by selected area electron diffraction, while EDX analysis showed the presence of silver as a prominent metal. The synthesized nanoparticles effectively inhibited multidrug-resistant isolates of Klebsiella pneumonia and Escherichia coli at a concentration of 40 µg/ml, and enhanced the activities of cefuroxime and ampicillin in synergistic manner at 42.9–100 % concentration, while it completely inhibited the growth of E. coli, K. pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus flavus, Aspergillus fumigatus and Aspergillus niger as additive in emulsion paint. The antioxidant activities of the CPHE-AgNPs were found to be excellent, while highly potent larvicidal activities against the larvae of Anopheles mosquito at 10–100 µg/ml concentration were observed. Our study demonstrated for the first time the utility of CPHE in the biosynthesis of CPHE-AgNPs with potential applications as antimicrobial and larvicidal agents, and paint additives for coating material surfaces to protect them against microbial growth while improving their shelf life.

/pdf/cocoa-pod-husk-extract-mediated-biosynthesis-of-silver-56b5u8g03l.pdf

Cocoa pod husk extract-mediated biosynthesis of silver nanoparticles: its antimicrobial, antioxidant and larvicidal activities

Green synthesized silver nanoparticles by marine endophytic fungus Penicillium polonicum and its antibacterial efficacy against biofilm forming, multidrug-resistant Acinetobacter baumanii.

https://cyberleninka.org/article/n/1162079.pdf

Biofabrication, characterization and antibacterial efficacy of extracellular silver nanoparticles using novel fungal strain of Penicillium atramentosum KM

Manjit K. Selwal

Papers

Biofabrication, characterization and antibacterial efficacy of extracellular silver nanoparticles using novel fungal strain of Penicillium atramentosum KM