Green Synthesis of Silver Nanoparticles by Using Various Reducing Agents

The experiments aimed at the green synthesis of silver nanoparticles (AgNPs) with various reducers like plant extracts and glucose and the evaluation of their antimicrobial efficiency versus their nanotoxicity. Precursor silver ions were reduced with extracts of Coffea arabica leaves, Thuja orientalis cones, and Cirsium arvense roots as well as with glucose. The AgNP microstructural properties were analyzed with transmission electron microscopy and dynamic light scattering that highlighted fine granulation (23 to 28 nm) and electrical stability (Zeta potential of −15 to −25 mV) while optical and spectral investigations like dark-field microscopy, UV-Vis spectroscopy and FTIR proved specific surface properties. Since cytotoxicity is related to the fate of AgNPs in the environment after their uses, we highlighted the presence of chromosomal alterations in the meristematic tissues of maize roots, such as delayed and expelled chromosomes, chromosome bridges, multi-polar anaphases, C-metaphases and others. Silver nanoparticle use in biomedical applications and antimicrobial activity against Gram-positive and Gram-negative pathogens was evidenced by the agar diffusion test, which suggested their usefulness in the case of possible antibiotic-resistant microbial strains with available natural ingredients and at low cost.