Biological Synthesis of Silver Nanoparticles and Prospects in Plant Disease Management

Exploration of nanoparticles (NPs) for various biological and environmental applications has become one of the most important attributes of nanotechnology. Due to remarkable physicochemical properties, silver nanoparticles (AgNPs) are the most explored and used NPs in wide-ranging applications. Also, they have proven to be of high commercial use since they possess great chemical stability, conductivity, catalytic activity, and antimicrobial potential. Though several methods including chemical and physical methods have been devised, biological approaches using organisms such as bacteria, fungi, and plants have emerged as economical, safe, and effective alternatives for the biosynthesis of AgNPs. Recent studies highlight the potential of AgNPs in modern agricultural practices to control the growth and spread of infectious pathogenic microorganisms since the introduction of AgNPs effectively reduces plant diseases caused by a spectrum of bacteria and fungi. In this review, we highlight the biosynthesis of AgNPs and discuss their applications in plant disease management with recent examples. It is proposed that AgNPs are prospective NPs for the successful inhibition of pathogen growth and plant disease management. This review gives a better understanding of new biological approaches for AgNP synthesis and modes of their optimized applications that could contribute to sustainable agriculture

Facile, polyherbal drug-mediated green synthesis of CuO nanoparticles and their potent biological applications

Copper oxide nanoparticles (CuO NPs) were synthesized using ayurvedic medicine septilin. The septilin-mediated CuO NPs were characterized using UV–Vis, fourier-transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The average particle size of CuO NPs was 8 nm as evident from TEM. Minimum inhibitory concentration of CuO NPs against Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans was found in the range of 1–2.5 mg·mL−1. CuO NPs dose-dependently decreased the biofilm formation from 0.0315 to 2 mg·mL−1, at the highest dose of 2 mg·mL−1 of CuO NPs; 92.91%, 79.84%, and 71.57% decrease in biofilm was observed for P. aeruginosa, MRSA, and C. albicans, respectively. Down-regulation of biofilm upon treatment with nanoparticles (NPs) was also observed by SEM analysis. SEM analysis also showed the change in morphological structure, and deformities in bacterial and fungal cells upon treatment of NPs. Furthermore, the anticancer efficacy of NPs was assessed using colon cancer (HCT-116). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay clearly showed the anticancer potential of NPs, as the concentration of CuO NPs increased, the number of viable cells decreased. The produced CuO NPs have promise for future investigations in many biological and therapeutic domains, including the treatment of microbial biofilm infections, as well as the inhibition of cancer cell growth