Ocimum tenuiflorum leaf extract as a green mediator for the synthesis of ZnO nanocapsules inactivating bacterial pathogens

A critical review on the recent trends of photocatalytic, antibacterial, antioxidant and nanohybrid applications of anatase and rutile TiO2 nanoparticles

Titanium dioxide nanoparticles (TiO2 NPs) have become a focal point of research due to their widespread daily use and diverse synthesis methods, including physical, chemical, and environmentally sustainable approaches. These nanoparticles possess unique attributes such as size, shape, and surface functionality, making them particularly intriguing for applications in the biomedical field. The continuous exploration of TiO2 NPs is driven by the quest to enhance their multifunctionality, aiming to create next-generation products with superior performance. Recent research efforts have specifically focused on understanding the anatase and rutile phases of TiO2 NPs and evaluating their potential in various domains, including photocatalytic processes, antibacterial properties, antioxidant effects, and nanohybrid applications. The hypothesis guiding this research is that by exploring different synthesis methods, particularly chemical and environmentally friendly approaches, and incorporating doping and co-doping techniques, the properties of TiO2 NPs can be significantly improved for diverse applications. The study employs a comprehensive approach, investigating the effects of nanoparticle size, shape, dose, and exposure time on performance. The synthesis methods considered encompass both conventional chemical processes and environmentally friendly alternatives, with a focus on how doping and co-doping can enhance the properties of TiO2 NPs. The research unveils valuable insights into the distinct phases of TiO2 NPs and their potential across various applications. It sheds light on the improved properties achieved through doping and co-doping, showcasing advancements in photocatalytic processes, antibacterial efficacy, antioxidant capabilities, and nanohybrid applications. The study concludes by emphasizing regulatory aspects and offering suggestions for product enhancement. It provides recommendations for the reliable application of TiO2 NPs, addressing a comprehensive spectrum of critical aspects in TiO2 NP research and application. Overall, this research contributes to the evolving landscape of TiO2 NP utilization, offering valuable insights for the development of innovative and high-performance products.

Removal of organic dyes and free radical assay by encapsulating polyvinylpyrrolidone and Tinospora Cordifolia in dual (Co-Cu) doped TiO2 nanoparticles

Aquatic pollution refers to any water that has been used and discarded in different water bodies by industrial and commercial activities which contains a wide range of toxic substances and required treatment so that water can be safely reused for various purposes. In present paper, polymer polyvinylpyrrolidone (PVP) and plant Tinospora Cordifolia (T. Cordifolia) encapsulated dual doped cobalt-copper titanium dioxide nanoparticles (Co-Cu TNPs) has been synthesized via microwave-assisted method for the degradation aquatic pollutant dyes: Methyl Orange (MO) & Methylene Blue (MB). Using the encapsulated dual doped Co-Cu TNPs, free radical assays (2,2-diphenyl-1-picrylhydrazyl: DPPH; Hydrogen peroxide: HP & Nitric oxide: NO) were also performed. Several physicochemical properties of encapsulated TNPs were examined using a variety of characterization techniques that helps in photocatalytic and antioxidant activity. The encapsulated TNPs exhibit tetragonal crystal lattice having average particles size between 25 and 38 nm with spherical shape morphology. The bandgap of encapsulated dual doped Co-Cu TNPs was found in the range of 3.25-3.29 eV. The binding of encapsulated dual doped Co-Cu TNPs were also calculated by using XPS which confirms the presence of dopants. The photocatalytic activity was performed with using control experiment and using encapsulated dual doped Co-Cu TNPs against MO and MB dyes. The results revealed that the degradation was observed up to 100% for the both MO and MB dyes. Also, antioxidant activity of encapsulated dual doped Co-Cu TNPs was observed against the DPPH, HO and NO assays.

Alpinia officinarum mediated copper oxide nanoparticles: synthesis and its antifungal activity against Colletotrichum gloeosporioides

Green synthesis offers an environmentally friendly and cost-effective alternative for the synthesis of copper oxide nanoparticles (CuO NPs). In this study, the synthesis of CuO NPs was optimized by using copper sulfate (CuSO₄) and the aqueous extract of Alpinia officinarum and its antifungal activity were investigated. The synthesized CuO NPs were characterized by UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Fourier-transform infrared radiation spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). The results showed that the optimized conditions for the synthesis of CuO NPs were 1:2 ratio of extract and CuSO₄ solution, pH 7, and 30 °C. The characteristic UV-vis peak of A. officinarum synthesized CuO NPs was at 264 nm. The synthesized CuO NPs had high crystallinity and purity and were spherical in morphology with the mean size of 46.40 nm. The synthesized CuO NPs reduced the fungal growth of Colletotrichum gloeosporioides in a dose-dependent manner. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the CuO NPs were 125 μg·mL^-1 and 500 μg·mL^-1, respectively. The antifungal activity of CuO NPs may be attributed to its ability to deform the structure of fungal hyphae, induce excessive reactive oxygen species accumulation and lipid peroxidation in fungi, disrupt the mycelium cell membrane, and result cellular leakage.

Antibacterial and Photodegradation of Organic Dyes Using Lamiaceae-Mediated ZnO Nanoparticles: A Review

The green synthesis of zinc oxide nanoparticles (ZnO NPs) using plant extracts has been receiving tremendous attention as an alternative to conventional physical and chemical methods. The Lamiaceae plant family is one of the largest herbal families in the world and is famous for its aromatic and polyphenolic biomolecules that can be utilised as reducing and stabilising agents during the synthesis of ZnO NPs. This review will go over the synthesis and how synthesis parameters affect the Lamiaceae-derived ZnO NPs. The Lamiaceae-mediated ZnO NPs have been utilised in a variety of applications, including photocatalysis, antimicrobial, anticancer, antioxidant, solar cells, and so on. Owing to their optical properties, ZnO NPs have emerged as potential catalysts for the photodegradation of organic dyes from wastewater. Furthermore, the low toxicity, biocompatibility, and antibacterial activity of ZnO against various bacteria have led to the application of ZnO NPs as antibacterial agents. Thus, this review will focus on the application of Lamiaceae-mediated ZnO NPs for the photodegradation of organic dyes and antibacterial applications.

An Evaluation of the Biocatalyst for the Synthesis and Application of Zinc Oxide Nanoparticles for Water Remediation—A Review

Global water scarcity is threatening the lives of humans, and it is exacerbated by the contamination of water, which occurs because of increased industrialization and soaring population density. The available conventional physical and chemical water treatment techniques are hazardous to living organisms and are not environmentally friendly, as toxic chemical elements are used during these processes. Nanotechnology has presented a possible way in which to solve these issues by using unique materials with desirable properties. Zinc oxide nanoparticles (ZnO NPs) can be used effectively and efficiently for water treatment, along with other nanotechnologies. Owing to rising concerns regarding the environmental unfriendliness and toxicity of nanomaterials, ZnO NPs have recently been synthesized through biologically available and replenishable sources using a green chemistry or green synthesis protocol. The green-synthesized ZnO NPs are less toxic, more eco-friendly, and more biocompatible than other chemically and physically synthesized materials. In this article, the biogenic synthesis and characterization techniques of ZnO NPs using plants, bacteria, fungi, algae, and biological derivatives are reviewed and discussed. The applications of the biologically prepared ZnO NPs, when used for water treatment, are outlined. Additionally, their mechanisms of action, such as the photocatalytic degradation of dyes, the production of reactive oxygen species (ROS), the generation of compounds such as hydrogen peroxide and superoxide, Zn2+ release to degrade microbes, as well as their adsorbent properties with regard to heavy metals and other contaminants in water bodies, are explained. Furthermore, challenges facing the green synthesis of these nanomaterials are outlined. Future research should focus on how nanomaterials should reach the commercialization stage, and suggestions as to how this ought to be achieved are presented.

Phytoantioxidant Functionalized Nanoparticles: A Green Approach to Combat Nanoparticle-Induced Oxidative Stress

Nanotechnology is gaining significant attention, with numerous biomedical applications. Silver in wound dressings, copper oxide and silver in antibacterial preparations, and zinc oxide nanoparticles as a food and cosmetic ingredient are common examples. However, adverse effects of nanoparticles in humans and the environment from extended exposure at varied concentrations have yet to be established. One of the drawbacks of employing nanoparticles is their tendency to cause oxidative stress, a significant public health concern with life-threatening consequences. Cardiovascular, renal, and respiratory problems and diabetes are among the oxidative stress-related disorders. In this context, phytoantioxidant functionalized nanoparticles could be a novel and effective alternative. In addition to performing their intended function, they can protect against oxidative damage. This review was designed by searching through various websites, books, and articles found in PubMed, Science Direct, and Google Scholar. To begin with, oxidative stress, its related diseases, and the mechanistic basis of oxidative damage caused by nanoparticles are discussed. One of the main mechanisms of action of nanoparticles was unearthed to be oxidative stress, which limits their use in humans. Secondly, the role of phytoantioxidant functionalized nanoparticles in oxidative damage prevention is critically discussed. The parameters for the characterization of nanoparticles were also discussed. The majority of silver, gold, iron, zinc oxide, and copper nanoparticles produced utilizing various plant extracts were active free radical scavengers. This potential is linked to several surface fabricated phytoconstituents, such as flavonoids and phenols. These phytoantioxidant functionalized nanoparticles could be a better alternative to nanoparticles prepared by other existing approaches.