A rapid microwave-assisted synthesis of silver nanoparticles using Ziziphus jujuba Mill fruit extract and their catalytic and antimicrobial properties

Phyto-fabrication of silver nanoparticles and their catalytic dye degradation and antifungal efficacy

The biogenic synthesis of silver nanoparticles (AgNPs) and their potent application against dye degradation and phytopathogens are attracting many scientists to nanotechnology. An attempt was made to synthesize silver nanoparticles using Plantago ovata leaf extract and test their effectiveness in removing organic dyes and antifungal activity. In the present study, stable AgNPs were synthesized from 0.1 mM AgNO₃ and authenticated by observing the color change from yellow to red-brown, which was confirmed with wavelength UV-Vis spectrophotometer detection. The crystalline nature of the particles was characterized by x-ray diffraction (XRD) patterns. Furthermore, the AgNPs were characterized by high-resolution transmission electron microscope and scanning electron microscope investigations. Atomic force microscopy (AFM) and Raman spectra were also used to confirm the size and structure of the synthesized AgNPs. The elemental analysis and functional groups responsible for the reduction of AgNPs were analyzed by electron dispersive spectroscopy and fourier transform infra-red spectroscopy Fourier transforms infrared, respectively. A new biological approach was taken by breaking down organic dyes such as methylene blue and congo red. The AgNPs effectively inhibit the fungal growth of Alternaria alternata. This could be a significant achievement in the fight against many dynamic pathogens and reduce dye contamination from waste water.

Non-Thermal Plasma Reduction of Ag+ Ions into Silver Nanoparticles in Open Atmosphere under Statistically Optimized Conditions for Biological and Photocatalytic Applications

An environmentally friendly non-thermal DC plasma reduction route was adopted to reduce Ag+ ions at the plasma−liquid interface into silver nanoparticles (AgNPs) under statistically optimized conditions for biological and photocatalytic applications. The efficiency and reactivity of AgNPs were improved by statistically optimizing the reaction parameters with a Box−Behnken Design (BBD). The size of the AgNPs was chosen as a statistical response parameter, while the concentration of the stabilizer, the concentration of the silver salt, and the plasma reaction time were chosen as independent factors. The optimized parameters for the plasma production of AgNPs were estimated using a response surface methodology and a significant model p < 0.05. The AgNPs, prepared under optimized conditions, were characterized and then tested for their antibacterial, antioxidant, and photocatalytic potentials. The optimal conditions for these three activities were 3 mM of stabilizing agent, 5 mM of AgNO3, and 30 min of reaction time. Having particles size of 19 to 37 nm under optimized conditions, the AgNPs revealed a 82.3% degradation of methyl orange dye under UV light irradiation. The antibacterial response of the optimized AgNPs against S. aureus and E. coli strains revealed inhabitation zones of 15 mm and 12 mm, respectively, which demonstrate an antioxidant activity of 81.2%.

Synergistic effect of plant extract coupled silver nanoparticles in various therapeutic applications- present insights and bottlenecks

The phytocomponent conjugated silver nanoparticles (AgNPs) have been extensively explored for various therapeutic applications such as antimicrobial, antioxidant, anticancer, anti-inflammatory, antidiabetic and anticoagulant effects. The bio-conjugation of Ag-based nanomaterial with plant extracts reduces their toxicity to biological systems and enhances their therapeutic effectiveness. The diversity of phytochemicals or capping agents provided by the plant extracts and the small size and large surface area of AgNPs permits maximum adsorption of these capping agents onto their surfaces that further promote the therapeutic performance of phytoconjugated AgNPs in various biomedical applications. The mechanistic action involved in antimicrobial and anticancer functions of AgNPs is mainly dependent on the induction of reactive oxygen species (ROS) resulting in cellular apoptosis and necrosis. This review summarizes the recent studies of various plant extract assisted synthesis of AgNPs, potential biomedical applications with the possible mechanism of action and major shortcomings affecting their therapeutic efficacy.