Biosynthesis of silver nanoparticles using Momordica charantia leaf broth: Evaluation of their innate antimicrobial and catalytic activities

Antibacterial efficacy of silver nanoparticles synthesized employing Terminalia arjuna bark extract

In the present investigation, we have explored simple, robust, inexpensive, and eco-friendly method for the synthesis of silver nanoparticles (AgNPs) using Terminalia arjuna bark extract (TA-AgNPs). Various parameters dictating the biosynthesis of TA-AgNPs such as time and temperature of reaction, concentration of AgNO₃, and T. arjuna extract amount were investigated. Characterization of TA-AgNPs was done via UV-vis spectroscopy along with FT-IR, XRD, SEM and dynamic light scattering. The antimicrobial activity of TA-AgNPs was investigated against Escherichia coli. Comparable zone of inhibition was exhibited by TA-AgNPs. This study suggests that TA-AgNPs possesses significant antibacterial properties.

Biosynthesis of silver nanoparticles by the fungus Arthroderma fulvum and its antifungal activity against genera of Candida, Aspergillus and Fusarium

The objective of this study was to find one or more fungal strains that could be utilized to biosynthesize antifungal silver nanoparticles (AgNPs). Using morphological and molecular methods, Arthroderma fulvum was identified as the most effective fungal strain for synthesizing AgNPs. The UV-visible range showed a single peak at 420 nm, which corresponded to the surface plasmon absorbance of AgNPs. X-ray diffraction and transmission electron microscopy demonstrated that the biosynthesized AgNPs were crystalline in nature with an average diameter of 15.5±2.5 nm. Numerous factors could potentially affect the process of biosynthesis, and the main factors are discussed here. Optimization results showed that substrate concentration of 1.5 mM, alkaline pH, reaction temperature of 55°C, and reaction time of 10 hours were the optimum conditions for AgNP biosynthesis. Biosynthesized AgNPs showed considerable activity against the tested fungal strains, including Candida spp., Aspergillus spp., and Fusarium spp., especially Candida spp.