Biosynthesized δ-Bi2O3 Nanoparticles from Crinum viviparum Flower Extract for Photocatalytic Dye Degradation and Molecular Docking.

Bioinspired delta-bismuth oxide nanoparticles (δ-Bi2O3 NPs) have been synthesized using a greener reducing agent and surfactant via co-precipitation method. The originality of this work is the use of Crinum viviparum flower extract for the first time for the fabrication of NPs, which were further calcined at 800 °C to obtain δ-Bi2O3 NPs. Physicochemical studies such as FTIR spectroscopy and XPS confirmed the formation of Bi2O3 NPs, whereas XRD and Raman verified the formation of the cubic delta (δ) phase of Bi2O3 NPs. However, HRTEM revealed the spherical shape with diameter 10-20 nm, while BET studies expose mesoporous nature with a surface area of 71 m2/gm. The band gap for δ-Bi2O3 NPs was estimated to be 3.45 eV, which ensured δ-Bi2O3 to be a promising photocatalyst under visible-light irradiation. Therefore, based on the results of physicochemical studies, the bioinspired δ-Bi2O3 NPs were explored as active photocatalysts for the degradation of toxic dyes, viz., Thymol blue (TB) and Congo red (CR) under visible-light irradiation. The study showed 98.26% degradation of TB in 40 min and 69.67% degradation of CR in 80 min by δ-Bi2O3 NPs. The photogenerated holes and electrons were found responsible for this enhancement. Furthermore, molecular docking investigations were also performed for δ-Bi2O3 NPs to understand its biological function as New Delhi metallo-ß-lactamase 1 (NDM-1) [PDB ID 5XP9] enzyme inhibitor, and studies revealed good interaction with various amino acid residues and found good hydrogen bonding with a fine pose energy of -3.851 kcal/mole.

Bioinspired NiO Nanospheres: Exploring In Vitro Toxicity Using Bm-17 and L. rohita Liver Cells, DNA Degradation, Docking, and Proposed Vacuolization Mechanism.

The present work demonstrated a novel Cleome simplicifolia-mediated green fabrication of nickel oxide nanoparticles (NiO NPs) to explore in vitro toxicity in Bm-17 and Labeo rohita liver cells. As-fabricated bioinspired NiO NPs were characterized by several analytical techniques. X-ray diffraction (XRD) revealed a crystalline face-centered-cubic structure. Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) confirmed NiO formation. The chemical composition was confirmed by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy. Brunauer-Emmett-Teller (BET) revealed the mesoporous nature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the formation of 97 nm diameter nanospheres formed due to the congregation of 10 nm size particles. Atomic force microscopy (AFM) revealed the nearly isotropic behavior of NiO NPs. Further, a molecular docking study was performed to explore their toxicity by binding with genetic molecules, and it was found that the docking energy was about -9.65284 kcal/mol. On evaluating the in vitro toxicity of NiO NPs for Bm-17 cells, the study showed that when cells were treated with a high concentration of NPs, cells were affected severely by toxicity, while at a lower concentration, cells were affected slightly. Further, on using 50 µg/mL, quick deaths of cells were observed due to the formation of more vacuoles in the cells. The DNA degradation study revealed that NiO NPs are significantly responsible for DNA degradation. For further confirmation, trypan blue assay was observed for cell viability, and morphological assessment was performed using inverted tissue culture microscopy. Further, the cytotoxicity of NiO NPs in L. rohita liver cells was studied. No toxicity was observed at 1 mg/L of NiO NPs; however, when the concentration was 30 and 90 mg/L, dark and shrank hepatic parenchyma was observed. Hence, the main cause of cell lysis is the increased vacuolization in the cells. Thus, the present study suggests that the cytotoxicity induced by NiO NPs could be used in anticancer drugs.

Biogenic Synthesis of Metal/Metal Oxide Nanostructured Materials.

Nanotechnology is an emerging outlet of nanoscience in which the atoms are encompassed in nanoscale dimensions and become more receptive compared with their distinctive counterparts. Recently, the utilization of synthetic designs and physicochemical approaches has received special attention; nevertheless, the generation of noxious impressions on the eco-system has raised serious concerns of the scientific community worldwide. Presently, environment-friendly green synthesis routes are promising venues for the arrangement of Metal/Metal Oxide (M/MO) nanostructured materials by using plants and their corresponding alliances. This revolution is predominantly recompensing as far as the reduction of toxic emissions and wastes is concerned. Accordingly, material scientists have adopted various renewable naturally-occurring eco-friendly materials, and biogenic processes to fabricate the functional M/MO nanostructured materials. The current review article recapitulates and assimilates the present state of knowledge on different strategies for biogenic fabrication of M/MO nanostructured materials.

Phytosynthesis of nearly monodisperse CuO nanospheres using Phyllanthus reticulatus/Conyza bonariensis and its antioxidant/antibacterial assays.

In the present article we have developed an eco-friendly, phytosynthetic, cost-effective and straightforward method for the synthesis of nearly monodisperse CuO nanospheres (NSP) using leaf extracts of medicinal plants Phyllanthus reticulatus (PR) and Conyza bonariensis (CB) as novel green reducing agents. Copper nitrate (Cu (NO3)2) was used as a precursor. The stoichiometric ratio of both leaf extracts (PR/CB) and Cu(NO3)2 was standardized for the synthesis of NSP. During formation of CuO NSP, a color of solution gradually changed from light greenish-blue to black with a number of intermediate stages and it correlated to the reduction reaction catalyzed by phytochemicals. As-synthesized materials were characterized in detail at the structural, electronic level and morphological authentication by XRD, FT-IR, EDS, UV-DRS, Raman, XPS, SEM, TEM, BET and AFM. SEM studies of phytosynthesized materials revealed nearly monodisperse nanospheres, while TEM rendered average particles size 4-14 nm. Also, AFM profiles suggested a homogenized nature of the nanospheres. Then, the antioxidant property was obtained by α, α-diphenyl-ß-picrylhydrazyl (DPPH). Ethanolic, methanolic extracts were used for the antioxidant activity, while ascorbic acid was used as a standard medium. Each plant extract exhibited noteworthy antioxidant activity. Moreover, the antibacterial activity of CuO NSP (PR/CB) was tested against human pathogenic bacteria viz. gram-positive Staphylococcus aureus, Klebsiella pneumoniae, and gram-negative Escherichia coli. Result rendered effective antibacterial activity against Escherichia coli.