Copper oxide nanoparticles (CuO NPs) are one of the most widely used nanomaterials nowadays. CuO NPs have numerous applications in biological processes, medicine, energy devices, environmental remediation, and industrial fields from nanotechnology. With the increasing concern about the energy crisis and the challenges of chemical and physical approaches for preparing metal NPs, attempts to develop modern alternative chemistry have gotten much attention. Biological approaches that do not produce toxic waste and therefore do not require purification processes have been the subject of numerous studies. Plants may be extremely useful in the study of biogenic metal NP synthesis. This review aims to shed more light on the interactions between plant extracts and CuO NP synthesis. The use of living plants for CuO NPs biosynthesis is a cost-effective and environmentally friendly process. To date, the findings have revealed many aspects of plant physiology and their relationships to the synthesis of NPs. The current state of the art and potential challenges in the green synthesis of CuO NPs are described in this paper. This study found a recent increase in the green synthesis of CuO NPs using various plant extracts. As a result, a thorough explanation of green synthesis and stabilizing agents for CuO NPs made from these green sources is given. Additionally, the multifunctional applications of CuO NPs synthesized with various plant extracts in environmental remediation, sensing, catalytic reduction, photocatalysis, diverse biological activities, energy storage, and several organic transformations such as reduction, coupling, and multicomponent reactions were carefully reviewed. We expect that this review could serve as a useful guide for readers with a general interest in the plant extract mediated biosynthesis of CuO NPs and their potential applications. 

New frontiers in the plant extract mediated biosynthesis of copper oxide (CuO) nanoparticles and their potential applications: A review

New frontiers in the plant extract mediated biosynthesis of copper oxide (CuO) nanoparticles and their potential applications: A review.

Herein, we report the eco-benevolent fabrication of copper oxide nanoparticles (CuONPs) by a green process using Polyalthia longifolia leaf extract (PLLE). Phytochemical screening for the PLLE evinced the existence of tannins, terpenoids, saponins, phenols, glycosides, and flavonoids. The produced CuONPs were explored by using XRD, zeta potential, DLS, EDAX, HRTEM, BET-surface area, UV-DRS, photoluminescence, and FTIR to ascertain its structural, morphological, and optical properties. Besides, these CuONPs evinced noteworthy bactericidal performance against Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Streptococcus pyogenes (S. pyogenes), and good antifungal performance against Aspergillus niger (A. niger), Epidermophyton floccosum (E. floccosum), Aspergillus clavatus (A. clavatus), and Candida albicans (C. albicans). The results indicated that the proactive eco-benign fabrication of CuONPs by sustainable “green chemistry” approaches can offer a convenient alternative to orthodox multi-step strategies for the creation of CuONPs.

Structural Properties and Antimicrobial Activities of Polyalthia longifolia Leaf Extract-Mediated CuO Nanoparticles

Plants are rich in phytoconstituent biomolecules that served as a good source of medicine. More recently, they have been employed in synthesizing metal/metal oxide nanoparticles (NPs) due to their capping and reducing properties. This green synthesis approach is environmentally friendly and allows the production of the desired NPs in different sizes and shapes by manipulating parameters during the synthesis process. The most commonly used metals and oxides are gold (Au), silver (Ag), and copper (Cu). Among these, Cu is a relatively low-cost metal that is more cost-effective than Au and Ag. In this review, we present an overview and current update of plant-mediated Cu/copper oxide (CuO) NPs, including their synthesis, medicinal applications, and mechanisms. Furthermore, the toxic effects of these NPs and their efficacy compared to commercial NPs are reviewed. This review provides an insight into the potential of developing plant-based Cu/CuO NPs as a therapeutic agent for various diseases in the future.

https://www.mdpi.com/2218-273X/11/4/564/pdf

Plant-Based Biosynthesis of Copper/Copper Oxide Nanoparticles: An Update on Their Applications in Biomedicine, Mechanisms, and Toxicity

Green inspired synthesis of ZnO nanoparticles and its characterizations with biofilm, antioxidant, anti-inflammatory, and anti-diabetic activities

The green synthesis of CuO nanoparticles was synthesized by Allium sativum extract. The powder X-ray diffraction pattern explained the high crystalline nature and the calculated crystallite size in 25−35 nm. The Fourier transform infrared spectrum described the CuO bonding nature. The UV visible analysis reported the surface Plasmon resonance band at 398 nm. The Photoluminescence spectrum denoted the red band emission in the visible region. The particle size analyzer displayed the CuO nanoparticles in a 20−40 nm range of size. The SEM images manifested the spherical, oval-shaped morphology of CuO nanoparticles. The EDAX spectrum and mapping proved the purity of CuO with Cu and O occurrence. The HRTEM images confirmed the crystalline nature formation of CuO nanoparticles. The phytochemical analysis listed the phytochemicals contributed for CuO nanoparticle synthesis via Allium sativum extract. The antimicrobial activity reported the efficient infection on bacteria as well as fungi. The antioxidant activity demonstrated the potential ability of free radical scavenging activity. The potential anti-inflammatory activity against egg albumin has obtained. The anti larvicidal activity showed the notable potential nature of affection on Anopheles subpictus mosquito larvae. At 21st century, CuO nanoparticles from environment friendly synthesis have special efficient applications in drugs, optics, batteries, gas sensors, catalysts, cosmetics, and semiconductor applications. Moreover, CuO nanoparticles have future applications in formulating the drug for human life-threatening diseases and various dangerous cancer treatments.

R M Aswin Kumar

Papers

Green synthesis of CuO nanoparticles via Allium sativum extract and its characterizations on antimicrobial, antioxidant, antilarvicidal activities