Green Synthesis and Characterization of Silver Nanoparticles (AgNPs) Using Leaf Extract of Solanum nigrum and Assessment of Toxicity in Vertebrate and Invertebrate Aquatic Animals

A comparative study of the plant and animal peptone-capped silver nanoparticles on biological systems

This study presents an eco-friendly approach for synthesizing silver nanoparticles (AgNPs) by using the natural reducing and stabilizing capabilities of peptones extracted from both animal and plant sources, followed by an in-depth physicochemical characterization and a thorough assessment of their antioxidant, enzymatic, and toxicological properties. Advanced techniques were utilized for structural analysis of the nanoparticles (NPs), including transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FT-IR), and UV-visible (UV-vis) spectroscopy. The synthesized AgNPs were confirmed by a color change and characterized as spherical, with sizes of 32.20 nm (animal peptones) and 48.73 nm (plant peptones). Biological evaluation showed dose-dependent antioxidant and enzyme inhibitory activities, with animal-derived AgNPs exhibiting superior effects-83.40 % antioxidant activity, 73.06 % α-amylase inhibition, and 51.65 % urease inhibition at 1000 μg mL-1. Acute toxicity tests in mice revealed no adverse effects at 2 mg mL-1 via oral or intraperitoneal administration over 14 days. Overall, using peptones from animal and plant sources provides an environmentally friendly alternative to conventional chemical methods, promoting green chemistry approaches. These findings highlight the potential of peptone-derived AgNPs as effective antioxidants and enzyme inhibitors, suggesting promising applications in biomedical fields.

PVA/chitosan biofilms enriched with biosynthesized silver nanoparticles and tea tree oil: Towards multifunctional and environmentally friendly materials

This study aims to investigate the synergistic effects of biosynthesized silver nanoparticles (AgNPs) and tea tree oil (TTO) (0, 3, 5, and 7 wt%) on enhancing the functional properties of polyvinyl alcohol/chitosan (PVA/CS) nanobiofilms. The structural, morphological, mechanical, thermal, and physicochemical properties of the films were analyzed using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), mechanical tests, thermal conductivity, dielectric constant, swelling, and water solubility studies. FTIR analysis confirmed the successful incorporation of AgNPs and TTO, while SEM images revealed structural differences between silver nanoparticles synthesized using basil extract (B-AgNPs) and silver nanoparticles synthesized using bay leaf extract (BL-AgNPs), with BL-AgNPs-based films exhibiting a denser and more uniform morphology. TTO incorporation significantly influenced the dielectric properties, thermal conductivity, and water absorption behavior of the films, reducing their swelling ratio and enhancing their hydrophobicity. The biodegradation results demonstrated that the films containing 3 wt% TTO exhibited the highest degradation rates (up to 62.90 % after 21 days), indicating enhanced environmental sustainability. Research indicates that PVA/CS biofilms doped with TTO and enhanced with AgNPs, produced using eco-friendly techniques, show great promise as biodegradable substitutes for food packaging and wound dressing applications.

Recyclable Cu-Ag bimetallic nanocatalyst for radical scavenging, dyes removal and antimicrobial applications

An ecofriendly and cost effective green method has been used for the synthesis of recyclable, high functional nanoparticles. Bimetallic nanoparticles (BmNPs), Cu-Ag, have been synthesized using beetroot extract as reducing and capping agent. Formation of BmNPs was initially confirmed by UV-visible analysis, having distinct peaks of Ag at 429 nm and Cu at 628 nm. FTIR analysis also confirmed the association of bioactive phytochemicals with Cu-Ag nanoparticles. Crystallinity and morphology of BmNPs was determined through X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS) and energy dispersion X-ray spectroscopy (EDAX). The size of spherical shape Cu-Ag BmNPs was found to be 75.58 nm and EDAX studies confirmed the percent elemental composition of Cu and Ag in synthesized nanocatalyst. Results of different analysis provided supported evidences regarding the formation of BmNPs. Catalytic potential of BmNPs was tested for the degradation of rhodamine B (Rh-B), methylene blue (MB) and methyl orange (MO) dyes. Cu-Ag BmNPs exhibited outstanding catalytic activity for the degradation of selected organic dyes and percent degradation was recorded more than 90% for each dye. In addition, antiradical property of BmNPs was tested employing DPPH^● and ABTS^●+ assays and it was found to be promising. Synthesized BmNPs also exhibited strong antimicrobial activity against Salmonella typhimurium and Bacillus subtilis. Recyclability of nanoparticles was also evaluated and recovery from dye degradation reaction mixture was successfully achieved. The recovered nanoparticles exhibited same catalytic potential for the degradation of Rh-B. The objective of the current study was to synthesize BmNPs Cu-Ag employing a cost effective green method having promising catalytic, antiradical and antimicrobial potential. Further, BmNPs were reused after recovery from catalytic reactions, proving that BmNPs can be recycled having the same efficiency as that of a freshly prepared Cu-Ag BmNPs.

Plant-Mediated Green Synthesis of Ag NPs and Their Possible Applications: A Critical Review

The potential applications of Ag NPs are exciting and beneficial in a variety of fields; however, there is less awareness of the new risks posed by inappropriate disposal of Ag NPs. The Ag NPs have medicinal, plasmonic, and catalytic properties. The Ag NPs can be prepared via physical, chemical, or biological routes, and the selection of any specific route depends largely on the end-use. The downside of a physical and chemical approach is that it requires a wide space, high temperature, high temperature for a longer time to preserve the thermal stability of synthesized Ag NPs, and the use of toxic chemicals. Although these methods produce nanoparticles with high purity and well-defined morphology, it is critical to develop cost-effective, energy-efficient, and facile route, such as green synthesis; it suggests the desirable use of renewable resources by avoiding the use of additional solvents and toxic reagents in order to achieve the ultimate goal. However, each method has its pros and cons. The synthesized Ag NPs obtained using the green approach have larger biocompatibility and are less toxic towards the biotic systems. However, identifying the phytoconstituents that are responsible for nanoparticle synthesis is difficult and has been reported as a suitable candidate for biological application. The concentration of the effective bioreducing phytoconstituents plays a crucial role in deciding the morphology of the nanoparticle. Besides these reaction times, temperature, pH, and concentration of silver salt are some of the key factors that determine the morphology. Hence, careful optimization in the methodology is required as different morphologies have different properties and usage. It is due to which the development of methods to prepare nanoparticles effectively using various plant extracts is gaining rapid momentum in recent days. To make sense of what involves in the bioreduction of silver salt and to isolate the secondary metabolites from plants are yet challenging. This review focuses on the contribution of plant-mediated Ag NPs in different applications and their toxicity in the aquatic system.

Prospective Application of Nanoparticles Green Synthesized Using Medicinal Plant Extracts as Novel Nanomedicines

The use of medicinal plants in green synthesis of metal nanoparticles is increasing day by day. A simple search for the keywords "green synthesis" and "nanoparticles" yields more than 33,000 articles in Scopus. As of August 10, 2021, more than 4000 articles have been published in 2021 alone. Besides demonstrating the ease and environmental-friendly route of synthesizing nanomaterials, many studies report the superior pharmacological properties of green synthesized nanoparticles compared to those synthesized by other methods. This is probably due to the fact that bioactive molecules are entrapped on the surface of these nanoparticles. On the other hand, recent studies have confirmed the nano-dimension and biocompatibility of metal ash (Bhasma) preparations, which are commonly macerated with biological products and administered for the treatment of various diseases in Indian medicine since ancient times. This perspective article argues for the prospective medical application of green nanoparticles in the light of Bhasma.

The Recent Progress on Silver Nanoparticles: Synthesis and Electronic Applications

Nanoscience enables researchers to develop new and cost-effective nanomaterials for energy, healthcare, and medical applications. Silver nanoparticles (Ag NPs) are currently increasingly synthesized for their superior physicochemical and electronic properties. Good knowledge of these characteristics allows the development of applications in all sensitive and essential fields in the service of humans and the environment. This review aims to summarize the Ag NPs synthesis methods, properties, applications, and future challenges. Generally, Ag NPs can be synthesized using physical, chemical, and biological routes. Due to the great and increasing demand for metal and metal oxide nanoparticles, researchers have invented a new, environmentally friendly, inexpensive synthetic method that replaces other methods with many defects. Studies of Ag NPs have increased after clear and substantial support from governments to develop nanotechnology. Ag NPs are the most widely due to their various potent properties. Thus, this comprehensive review discusses the different synthesis procedures and electronic applications of Ag NPs.

Phytosynthesized Metallic Nanoparticles-between Nanomedicine and Toxicology. A Brief Review of 2019's Findings

Phytosynthesized nanoparticles represent a continuously increasing field of research, with numerous studies published each year. However, with the emerging interest in this area, the quality of the published works is also continuously increasing, switching from routine antioxidant or antimicrobial studies on trivial microbial lines to antibiotic-resistant strains or antitumoral studies. However, this increasing interest has not been not reflected in the studies regarding the toxicological effects of nanoparticles (NPs); this should be a subject of greatest interest, as the increasing administration of NPs in general (and phytosynthesized NPs in particular) could lead to their accumulation in the environment (soil, water and living organisms). The present review aims to present the most recent findings in the application of phytosynthesized NPs as antimicrobial and antitumoral agents, as well as the results regarding their toxicological potential.