This research work presents the synthesis, characterization, evaluation of the antibacterial and anticancer activity of ZnO nanopowders prepared by solution combustion method using the bio fuels Punica granatum L and Tamarindus indica L. The X-ray diffractograms of all the samples revealed the hexagonal Wurtzite structure with the standard JCPDS pattern of zincite [36–1451]. Surface morphology of the samples was studied by SEM. Particle shapes and sizes were determined by TEM. Qualitative phytochemical screening of the aqueous fruit extracts of Punica granatum L and T. indica L revealed the presence of many phyto-components in them. Toxicity of the nanopowders was tested on Gram-negative Escherichia coli MTCC 7410 and Pseudomonas aeruginosa MTCC 7903 by disk diffusion method. Minimum inhibitory concentration was determined by microbroth dilution technique. Anticancer activity of ZnO powders was tested against breast cancer cell line MCF-7 by MTT assay. The cytotoxicity was assessed by hemolytic activity

Nanotechnology is a fast-expanding area with a wide range of applications in science, engineering, health, pharmacy, and other fields. Among many techniques that are employed toward the production of nanoparticles, synthesis using green technologies is the simplest and environment friendly. Nanoparticles produced from plant extracts have become a very popular subject of study in recent decades due to their diverse advantages such as low-cost synthesis, product stability, and ecofriendly protocols. These merits have prompted the development of nanoparticles from a variety of sources, including bacteria, fungi, algae, proteins, enzymes, etc., allowing for large-scale production with minimal contamination. However, nanoparticles obtained from plant extracts and phytochemicals exhibit greater reduction and stabilization and hence have proven the diversity of properties, like catalyst/photocatalyst, magnetic, antibacterial, cytotoxicity, circulating tumor deoxy ribo nucleic acid (CT-DNA) binding, gas sensing, etc. In the current scenario, nanoparticles can also play a critical role in cleaning wastewater and making it viable for a variety of operations. Nano-sized photocatalysts have a great scope toward the removal of large pollutants like organic dyes, heavy metals, and pesticides in an eco-friendly and sustainable manner from industrial effluents. Thus, in this review article, we discuss the synthesis of several metal nanoparticles using diverse plant extracts, as well as their characterization via techniques like UV–vis (ultraviolet–visible), XRD (X-ray diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), FTIR (Fourier transform infrared spectroscopy), etc., and catalytic activity on various hazardous systems.

We describe the synthesis, structural and morphological characteristics of cobalt and nickel doped zinc oxide nanoparticles (ZnO NPs) by solution combustion technique by utilizing lemon juice as bio-fuel. Structural parameters were confirmed by the X-ray Rietveld refinement method, all the compounds were crystallized in the wurtzite hexagonal structure with space group P63mc (No. 186). Field emission scanning electron microscopy coupled with energy dispersive X-ray elemental mapping results revealed agglomerated spherical shaped particles and dopant ions were homogeneously distributed. Antibacterial, anticancer, and reactive oxygen species (ROS) generation activities were studied on undoped ZnO-, Co-, and Ni-doped ZnO nanoparticles upon un-exposed/exposed to ultraviolet radiations at 300 nm for 1 h. Antibacterial studies were performed against Salmonella enterica and Clostridium perfringens. Anticancer activity was tested on HeLa and MCF-7 cell lines. Generation of ROS was studied in J744 mouse macrophage cells. Doping of cobalt or nickel in the ZnO lattice enhanced antibacterial, anticancer, and oxidative response generation activities compared to undoped ZnO NPs. These activities were further improved upon exposure to ultraviolet radiations. Together, data indicate a direct activity of ZnO NPs against bacteria, cancer cells and simultaneously boosting host’s immunity via inducing activation of immune cells (mouse macrophage cells).