silver nanoparticle

This study reports the eco-friendly synthesis of gold (AuNPs) and silver (AgNPs) nanoparticles using the alcoholic root extract of Hymenodictyon orixense. The use of H. orixense root extract offers a novel approach in green synthesis, as it has been relatively underexplored.The nanoparticles were synthesized via a microwave-assisted method, utilizing extract of H. orixense as a reducing and stabilizing agent. The phytochemicals present in the extract played a crucial role in reducing the metal ions and stabilizing the resulting nanoparticles. The synthesis was confirmed by a visual colour change and characterized using various physicochemical techniques. The synthesized gold and silver nanoparticles showed characteristic surface plasmon resonance peak at 544 nm and 427 nm, respectively. They exhibited significant cytotoxicity against MCF-7 (breast cancer), A549 (lung cancer), and HepG2 (liver cancer) cell lines, with AuNPs exhibiting slightly higher cytotoxicity compared to AgNPs. Statistical analysis using ANOVA revealed that the cytotoxic effects of both AuNPs and AgNPs were significant (p < 0.001) compared to the untreated control cells. The study demonstrates the potential of H. orixense-mediated green synthesis in producing nanoparticles with promising anticancer properties. Quantitative comparisons revealed that AuNPs had lower IC50 values and higher antioxidant activity than extract and AgNPs. The significant cytotoxicity exhibited by these nanoparticles suggests their potential for further development as therapeutic agents. However, further studies are needed to elucidate the underlying mechanisms, optimize the synthesis process, and evaluate the in vivo efficacy and safety of these nanoparticles.

Synthesis of silver nanoparticle (SNP) has become an emerging trend in the field of nanotechnology. Here a greener method was approached to develop silver nanoparticles using extracted exopolysaccharides (EPS) from Pseudomonas fluorescens, a soil isolate from rhizosphere of the medicinal plant, Catharanthus roseus. The exopolysaccharide acted as a reducing and stabilizing agent in converting silver nitrate to silver nanoparticles. The fabricated SNPs were characterized by UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM) and FT-IR Spectroscopy. The FT-IR analysis revealed that proteins present in the polysaccharide served as a capping agent. This simple process was carried out for 5 days at room temperature at optimum pH 7. The dried SNP sample is found to be stable for more than 6 months. The present work also focused on SNPs’ antimicrobial effect by agar well diffusion technique and antioxidant activity by DPPH method. The EPS reduced SNP was found to be more active against Gram negative than Gram positive and also worked in inhibiting Candida sp. DPPH radical scavenging effect of SNP was highly effective than standard at a maximum concentration of 1mg/ml. The investigation thus showed that EPS stabilized SNP could be employed in several pharmaceutical purposes.