The green Se NPs (selenium nanoparticles) are formed by simple mixing of Withania somnifera (W. somnifera) leaves extract and selenious acid (H₂SeO₃) solution. This mixture was stirred which gave a dispersion of Se NPs conjugated with W. somnifera secondary metabolites. The work was focused to determine the phytochemical analysis of leaves extract, green synthesis, its characterization and its applications. Screening analysis showed enormous phytoconstituents in leaves aqueous extract and simultaneously, the synthesized Se NPs by FT-IR spectrum confirm the presence of functional groups which were associated with bioactive molecules. The total flavonoid, phenolic and tannin contents in the aqueous extract were found to be 12.74, 40.54, and 156.33 μg/mg respectively. The suspension solution confirms the formation of Se NPs showed (310 nm) by UV analysis. X-ray diffraction study exhibits the amorphous nature of Se NPs. Se NPs were spherical in shape within the diameter range of 45–90 nm by FE-SEM. The intense, narrow width of selenium has high purity and was identified using EDX. The TEM analysis exhibited the amorphous nature of particles. Green synthesized Se NPs were found to possess significant antioxidant activity (IC₅₀ – 14.81 μg/mg) and considerable antibacterial activity on Bacillus subtilis (12 mm), Klebsiella pneumoniae (14 mm) and Staphylococcus aureus (19.66 mm). Antiproliferative effects of Se NPs possess great growth control against A549 cells (IC₅₀ at 25 μg/ml). Se NPs exhibit efficient methylene blue (MB) dye degradation in the presence of sunlight. The present results support the advantages of green method for the production of Se NPs having potential activities.

Plant-mediated synthesis of selenium nanoparticles (Se-NPs) was carried out by a simple precipitation method using the aqueous extract of Diospyros montana. The leaf extract was used as a good capping and stabilizing agent and allowed the formation of stable nanoparticles. These Se-NPs were characterized using UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), DLS, zeta potential measurement and elemental analysis by energy-dispersive X-ray spectroscopy (EDX). The FT-IR spectrum confirms the presence of various functional groups in the aqueous leaf extract of Diospyros montana, which may possibly influence the reduction process of the nanoparticles. The XRD data confirmed the formation of crystalline Se-NPs. TEM and DLS analysis determined that the size of the Se-NPs ranges from 4 to 16 nm. The zeta potential obtained was −22.3 mV. The DPPH and the reducing power activity showed the potential antioxidant property of the biosynthesized Se-NPs. The nanoparticle suspension exhibited significant antimicrobial activity against microorganisms such as Gram (+) Staphylococcus aureus, Gram (−) Escherichia coli (bacteria) and Aspergillus niger (fungi). The cytotoxicity of Se-NPs was assayed against human breast-cancer cells (MCF-7). An anticancer property was found in that Se-NPs were able to inhibit the cell growth in a dose-dependent manner.

Despite zinc oxide nanoparticles (ZnONPs) being increasingly used as carriers in biomedical fields due to their multifaceted properties and therapeutic importance, better understanding of the mechanisms and cellular consequences resulting from their interaction with cells and cellular components has been warranted. In the present study, we investigate the size-dependent interaction of ZnONPs on RBCs, and its impact on cell viability, DNA damage, ROS generation and morphological changes, employing cellular and analytical methods. Size, charge, stability and solubility were confirmed by DLS, zeta potential, ICP-AES and TEM analysis. Further ICP-AES, TEM, spectroscopic observations and cell based assays showed that ZnONPs exhibited a size dependent impact on RBCs and haemoglobin (Hb), particularly size <50 nm. Conversely, ferulic acid (FA) conjugates and serum albumin significantly reduced the adverse effects exhibited by ZnONPs. The extent of DNA damage and ROS generation is comparatively low in ZnONPs-FA than in ZnONPs alone treated cells. Thus our study documents a novel conceptualization delineating the influence of size on the material properties and therapeutic potential of nanoparticle.