ZnO Nanoparticles Research Articles

Effects of Two Different Size ZnO Nanoparticles on the Growth of Aspergillus oryzae

Two different kinds of ZnO nanoparticles (NPs) with distinct particle sizes were synthesized by a precipitation method. For the first time, the effects of two distinct sizes ZnO NPs on the growth, photoluminescence properties and kojic acid (KA) yield of Aspergillus oryzae (A. oryzae) were examined. The findings showed that ZnO-A and -B NPs, with average particle sizes of 11.93 nm and 34.41[Formula: see text]nm, respectively, exhibited a hexagonal crystal structure. It was found that when the concentration of NPs was below 100[Formula: see text][Formula: see text]g/mL, ZnO NPs were nontoxic and served as activators to stimulate the growth of A. oryzae, and the biomass of solid and liquid medium, the total integral emission intensity, the content of extracellular protein and total organic carbon and KA yield of A. oryzae grown with ZnO-A (ZnO-B) NPs were about 2.19 (1.97), 2.47 (1.56), 1.67 (1.16), 2.45 (1.95), 0.47 (0.50) and 2.07 (1.37) times more than that of control sample (without NPs), respectively.

Enhancement of Antioxidants’ Enzymatic Activity in the Wheat Crop by Shewanela sp. Mediated Zinc Oxide Nanoparticles Against Heavy Metals Contaminated Wastewater

Enhancement of Antioxidants’ Enzymatic Activity in the Wheat Crop by Shewanela sp. Mediated Zinc Oxide Nanoparticles Against Heavy Metals Contaminated Wastewater

Evaluation of zinc oxide nanocomposites and L-ascorbic acid on meat quality during transport induced stress in birds of Sonali breed

The study assessed the efficacy of phytofabricated zinc oxide nanoparticles (CF-ZnONPs) and L-ascorbic acid in alleviating pre-slaughter transport induced stress in birds of Sonali breed (Cross bred of Rhode Island Red cocks and Fayoumi hens). A total of 120 birds were divided into four groups: negative control (T1) which were loaded in vehicle but not transported, Positive control (T2) birds were transported without any prior supplementation, T3 and T4 birds were transported with prior supplementation (a day before transportation) of CF-ZnONPs @100 µg/ml and L-ascorbic acid @82 µg/ml in drinking water. Results obtained observed significant reduction in live weight, meat colour and pH but increased drip loss percentage in T2 group. Significantly elevated H/L ratio was recorded in all transported groups. Increased cortisol and TSH levels and decreased thyroid hormones, Triiodothyronine and thyroxin (T3 and T4) levels were recorded in T2 group. However, supplementation with CF-ZnONPs and L-ascorbic acid notably reversed these adverse effects, restoring meat quality and other metabolic profiles. Notably, ascorbic acid exhibited greater efficacy, suggesting its superior role in mitigating transportation-induced stress. Overall, these findings highlight the importance of antioxidant supplementation in alleviating transport induced stress in birds.

Green synthesis of ZnO, Fe3O4, and TiO2 nanoparticles: exploring enhanced bacterial inhibition, catalysis, and photocatalysis for sustainable environmental applications

ABSTRACT This study investigates the physicochemical and biological properties of metal oxide nanoparticles (TiO2, ZnO, and Fe3O4) synthesised via the phytosynthesis method using an extract from Boerhaavia diffusa leaves (BDL). The proteins and phenols present in the BDL extract played essential roles in reducing and stabilising TiO2, ZnO, and Fe3O4 nanoparticles. The study reveals size-dependent morphological, structural, and biological characteristics of the produced nanoparticles. FTIR spectra confirm the involvement of BDL extract in the synthesis process of TiO2, ZnO, and Fe3O4 nanoparticles. Transmission electron microscopy (TEM) analysis of TiO2 nanoparticles identified small, spherical particles (9 nm in diameter). BDL-derived TiO2, ZnO, and Fe3O4 demonstrated significant photocatalytic activity, achieving degradation rates of 98.96%, 96.26%, and 94.42%, respectively, in the decomposition of mono-azo dye after 40 minutes of UV irradiation. The reaction rates for BDL-derived TiO2, ZnO, and Fe3O4 were 0.367/min, 0.186/min, and 0.061/min, respectively, when catalysing the reduction of 4-Nitrophenol (4-NP) to 4-Aminophenol using NaBH4. BDL-derived TiO2 nanoparticles exhibited significant antibacterial effectiveness, showing a 23.6 mm zone of inhibition against Salmonella typhi. The BDL-derived TiO2, ZnO, and Fe3O4 nanoparticles exhibited remarkable cytotoxicity against lung cancer cell lines with IC50 values of 76.36 µg/mL, 90.21 µg/mL, and 94.61 µg/mL, respectively. This study reveals the potential of BDL-derived TiO2, ZnO, and Fe3O4 nanoparticles for applications in antibacterial, anticancer, catalytic, and photocatalytic fields, contributing to sustainable development of multifunctional nanomaterials for various technical and environmental advancements.

Chitosan, Alginate and Polyethylene Glycol Capped Zinc Oxide Nanoparticles for Hyperthermia Applications

Functional oxides have been very ingeniously used for diverse applications, recently in biomedical applications. Among the functional oxides, zinc oxide nanoparticles (ZnONPs) have proven to be exceptional for biomedical applications. Chitosan (CS), alginate (Alg) and polyethylene glycol (PEG) have been explored in the synthesis of ZnONPs as potential capping agents for hyperthermia applications. X-rays diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Vibrating sample magnetometry (VSM) techniques have been used to analyze the crystallinity, absorbance, morphology and magnetic properties of the samples, respectively. In our research described here the hyperthermia analyses of ZnONPs and PEG, CS and Alg capped ZnONPs were conducted under an applied field of 180 Oe. The results indicated that the samples could reach elevated temperatures that fall within the therapeutic range. A high specific absorbance degree (SAR) was obtained for the capped samples when compared with the pristine sample, making them more suitable for hyperthermia applications.

Achieving performance and functionality in PLA-based packaging: Insights from hybrid composites with false banana (Enset) fiber and ZnO nanoparticles

The use of poly(lactic acid) (PLA)-based composites reinforced with natural fibers is becoming increasingly popular in sustainable packaging. However, these materials often lack adequate barriers and desirable functional properties. Concurrently, zinc oxide nanoparticles (ZnO NPs) have been incorporated into PLA-based composites to develop functional packaging films. Despite this progress, there is a gap in the literature regarding packaging materials that require both functional and performance properties, specifically those that combine natural fibers and ZnO NPs within the PLA matrix. This study aims to develop and optimize the effects of ZnO nanofillers and false banana, also called Enset fibers (EFs) as hybrid reinforcements in PLA matrices. A central composite design (CCD) approach was used to evaluate the effects of EFs at three levels (5 %, 15 %, and 25 % w/w) and ZnO NPs at three levels (0 %, 5 %, and 10 % w/w) on the performance (tensile and flexural strength) and functional properties (water and antibacterial activity) of the resulting nanocomposite materials. The findings indicate that the inclusion of ZnO NPs significantly enhanced both the performance and functional properties of the nanocomposites, whereas the inclusion of EFs improved the performance properties but reduced the functional properties of the nanocomposites. Ultimately, this study identified an optimal formulation for producing durable and functional composites for various packaging applications.

Development of Biodegradable Tapioca Starch Films Incorporating Green Synthesized Zinc oxide Nanoparticles for Enhanced Preservation and Packaging of Sweet lime Segments: A Study of Their Physical and Antimicrobial Properties

Development of Biodegradable Tapioca Starch Films Incorporating Green Synthesized Zinc oxide Nanoparticles for Enhanced Preservation and Packaging of Sweet lime Segments: A Study of Their Physical and Antimicrobial Properties

ZnO Nanoparticles-Induced MRI Alterations to the Rat Olfactory Epithelium and Olfactory Bulb after Intranasal Instillation.

Since zinc oxide (ZnO) nanoparticles (NPs) have been widely applied, the nano community and the general public have paid great attention to the toxicity of ZnO NPs. We detected 20-nm ZnO NPs biotoxicity following nasal exposure utilizing the non-invasive and real-time magnetic resonance imaging (MRI) technique. MR images were scanned in the rat olfactory epithelium (OE) and olfactory bulb (OB) on a 4.7 T scanner following the treatment (as early as 1 day and up to 21 days after), and the histological changes were evaluated. The influence of the size of the ZnO NPs and chemical components was also investigated. Our study revealed that 20-nm ZnO NPs induced obvious structural disruption and inflammation in the OE and OB at the acute stage. The results suggest that the real-time and non-invasive advantages of MRI allow it to observe and assess, directly and dynamically, the potential toxicity of long-term exposure to ZnO NPs in the olfactory system. These findings indicate the size-dependent toxicity of ZnO NPs with respect to the olfactory bulb. Further study is needed to reveal the mechanism behind ZnO NPs' toxicity.

Encapsulation of Phloroglucinol from Rosenvingea intricata Macroalgae with Zinc Oxide Nanoparticles against A549 Lung Cancer Cells

Background/Objectives: Phloroglucinol (PHL), a phenolic compound extracted from the brown alga Rosenvingea intricata, exhibits potent antioxidant and anticancer properties. This study aims to extract, purify, and characterize PHL, and further develop functionalized zinc oxide nanoparticles (ZnO NPs) loaded with PHL to enhance its therapeutic potential. Methods: PHL was extracted using acetone and purified through Sephadex LH-20 column chromatography, yielding a highly enriched fraction (F-3). The purified compound was characterized by FTIR, HPLC, NMR, and LC-MS. ZnO NPs were synthesized, PEGylated, and conjugated with PHL, forming ZnO-PEG-PHL NPs. Their characterization included DLS, zeta potential, XRD, SEM-EDAX, and encapsulation efficiency studies. Antioxidant assays (DPPH, FRAP, ABTS, RPA) were performed and in vitro cytotoxicity on A549 lung cancer cells were determined to evaluate the therapeutic efficacy of PHL. Results: The purified PHL fraction showed a high phenolic content (45.65 PHL mg/g), which was was confirmed by spectral analysis. The ZnO-PEG-PHL NPs increased in size from 32.36 nm to 46.68 nm, with their zeta potential shifting from −37.87 mV to −26.82 mV. The antioxidant activity was superior for the ZnO-PEG-PHL NPs in all assays, while the in vitro cytotoxicity tests showed an IC50 of 40 µg/mL compared to 60 µg/mL for the ZnO NPs and 70 µg/mL for PHL. Apoptotic studies revealed significant cell cycle arrest and apoptosis induction. Conclusions: The synthesized ZnO-PEG-PHL NPs demonstrated enhanced antioxidant and anticancer properties, making them promising candidates for cancer therapy and antioxidant applications.

Elucidation of biochemical and physiological modulations in Triticum aestivum induced by green synthesized nitrogen-enriched zinc nano-complexes

This study investigates the efficacy of a green synthesized nitrogen-rich zinc complex (Zn-NC) using quinoline (C9H7N) as the nitrogen-rich substrate to enhance growth and biochemical properties in wheat (Triticum aestivum). The performance of Zn-NC was compared to standard zinc oxide nanoparticles (ZnO-NPs). Both Zn-NC and ZnO-NPs were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), and dynamic light scattering (DLS). Three concentrations (100, 200, and 500 ppm) of each compound, along with a control, were applied to local soil samples (n=3). The physiological (biomass, elongation) and biochemical effects (chlorophyll, carotenoids, flavonoids, and phenols) on wheat were investigated. Potential phytotoxic effects were evaluated to establish the biostimulants' safety thresholds. Plants treated with green Zn-NC showed an average increase in shoot length of 25 % compared to the control group. The chlorophyll content in plants treated with ZnO-NPs increased by 18 %, while those treated with green Zn-NC increased by 12 % compared to control. Application of ZnO-NPs resulted in a 30 % increase in total yield, whereas green Zn-NC treatment led to a 22 % yield increase. The root biomass of plants treated with ZnO-NPs increased by 28 %, and those treated with green Zn-NC saw a 20 % increase compared to controls. Based on the optimization of overall results, the ZnO NPs showed phytotoxic effects at concentrations above 200 ppm, while green Zn-NC exhibited no significant phytotoxicity even at concentrations up to 300 ppm. This study delineates the optimal concentrations of Zn-NC and ZnO-NPs that can enhance nutrient delivery and yield in cereal crops while mitigating phytotoxic risks. The findings provide valuable insights into applying nano-biostimulants in agroecosystems, highlighting their potential to improve productivity and sustainability in agriculture.

The biosynthesis of ZnO nanoparticles using Synadenium grantii latex: characterization and evaluation of their antimicrobial activities

The steadily rising incidences of microbial and infectious diseases pose a direct threat to both human and animal sustainability. Over the previous 20 years, the expectations for eco-friendly nanoparticles application as contemporary medicinal agents have grown. This is why, as opposed to using hazardous chemicals, researchers have recently concentrated on simple, green, sustainable, and affordable ways to create nanoparticles. This research aimed to use the latex of Synadenium grantii to synthesize ZnO NPs (zinc oxide nanoparticles) using a simple and environmentally friendly technique. The observation of the maximum wavelength at 365 nm using Ultraviolet-visible (UV-Vis) spectrometry signified the formation of zinc oxide nanoparticles. The FT-IR (Fourier transform-infrared) spectrometry indicated the bands of various biomolecules (mainly polyphenols at 1541 cm-1 wavenumber) involved in reducing and capping zinc oxide nanoparticles. The XRD spectrum demonstrated the wurtzite phases of ZnO nanoparticles of 24 nm in size. The synthesized ZnO NPs demonstrated great anti-microbial potency compared to the positive control (ampicillin) as tested on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The study confirmed the presence of various chemical compounds in latex of Synadenium grantii responsible for the synthesis of ZnO NPs with enhanced anti-bacterial effects in comparison to the latex extract.

Development and analysis of Fe-doped ZnO nanoparticle-infused sisal fiber reinforced hybrid polymer composites for high-performance sound absorption and thermal insulation applications

In the current study, sisal fiber-reinforced hybrid composites have been developed by integrating a bidirectional mat with a blend of epoxy using Fe-doped ZnO (IDZO) nanoparticles at concentrations of 0.2, 0.4, 0.6, and 0.8 wt%. Hand-lay-up approach was used to create the composites. The composites were characterized through a comprehensive analysis of their density, water absorption, elasticity, thermogravimetric analysis, mechanical resistance, thermal conductivity, microhardness, and propagation of sound properties, including sound absorption coefficients and sound transmission class ratings. As filler loading increased, the bio-composite sample’s hardness increased under the density and void volume fraction values, with 0.8 wt% composite sample showing the superior micro-hardness. A positive correlation was observed between the ZnO nanoparticle weight percentage and thermal conductivity, with improve nanoparticle content leading to improved thermal performance. Composites containing 0.4 wt percent nanoparticles showed superior tensile strength (66.8–84.16 MPa), flexural strength (97.69–120.02 MPa) and flexural modulus (3.56–7.68 GPa). It has been observed that the weight percentage of IDZO filler greatly influences the sound absorption efficiency of the current composites. These findings highlight the promising potential of these novel biocomposites in advanced engineering applications, emphasizing their usefulness in demanding environments with biodegradability and high-performance thermal, mechanical, and acoustic properties. Based on the sound transmission class ratings, the sisal fiber biocomposites have been regarded as great adoptions for use as sound-absorbing materials such as wall partitions, doors, enclosures, and structural components, thermal insulation systems, and electrical insulation.

Evaluating the impact of biogenic nanoparticles and pesticide application in controlling cotton leaf curl virus disease (CLCuD) in cotton (Gossypium hirsutum L.)

BackgroundCotton leaf curl virus disease (CLCuD) is one of the major concerns for cotton growers. The traditional approach to managing CLCuD involves the control of the vector (whitefly) population through the use of pesticides. This study compares the efficacy of zinc oxide, iron oxide, copper and silver nanoparticles with conventional pesticides. Nanoparticles dose was optimized by evaluating their phytotoxic threshold in our previous study. In this study, optimized doses of nanoparticles such as zinc oxide (100 ppm), iron oxide (50 ppm), copper (50 ppm) and silver nanoparticles (25 ppm) were applied in a field trial of cotton against cotton leaf curl virus disease (CLCuD). Morphological parameters (height of stem, monopodial branches, sympodial branches, staple length, boll weight and number of bolls), yield parameters (seed cotton yield and ginning outturn), chlorophyll content (chlorophyll a, chlorophyll b, carotenoids and total chlorophyll), biochemical parameters (superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), hydrogen peroxide (H2O2) and electrolyte leakage) and disease parameters (reduction infection, disease severity and disease incidence) were determined in this study.ResultsThe incidence of cotton leaf curl virus was confirmed by triple antibody sandwich–enzyme-linked immunosorbent assay (TAS-ELISA). The pesticide Imidacloprid significantly reduced the infection by 79.3%. However, in comparison to pesticide, application of nanoparticles also reduced the infection. ZnO NPs reduced the infection by 42.33%, FeO NPs by 41%, Cu NPs by 34.7%, and Ag NPs by 44.8%. Moreover, these nanoparticles also improved the plant growth parameters as compared to control treatment. ZnO NPs enhanced morphological, yield parameters, and chlorophyll content by 36%, 22%, and 29%, respectively. FeO NPs showed improvements by 38%, 21%, and 29%; Cu NPs 39%, 25%, and 29%; and Ag NPs 31%, 19%, and 18%, respectively.ConclusionAlthough treatment pesticide showed the least disease incidence compared to nanoparticles, nanoparticles are eco-friendly and safe as compared to pesticides. Farmers can apply these nanoparticles at their optimal thresholds through foliar application as an alternative to traditional pesticides. It is concluded that nanocomposites and hybrid modes may be used for managing CLCuD efficiently in the future.Graphical abstract

Cytotoxic Potencies of Zinc Oxide Nanoforms in A549 and J774 Cells.

Zinc oxide nanoparticles (NPs) are used in a wide range of consumer products and in biomedical applications, resulting in an increased production of these materials with potential for exposure, thus causing human health concerns. Although there are many reports on the size-related toxicity of ZnO NPs, the toxicity of different nanoforms of this chemical, toxicity mechanisms, and potency determinants need clarification to support health risk characterization. A set of well-characterized ZnO nanoforms (e.g., uncoated ca. 30, 45, and 53 nm; coated with silicon oil, stearic acid, and (3-aminopropyl) triethoxysilane) were screened for in vitro cytotoxicity in two cell types, human lung epithelial cells (A549), and mouse monocyte/macrophage (J774) cells. ZnO (bulk) and ZnCl2 served as reference particles. Cytotoxicity was examined 24 h post-exposure by measuring CTB (viability), ATP (energy metabolism), and %LDH released (membrane integrity). Cellular oxidative stress (GSH-GSSG) and secreted proteins (targeted multiplex assay) were analyzed. Zinc oxide nanoform type-, dose-, and cell type-specific cytotoxic responses were seen, along with cellular oxidative stress. Cell-secreted protein profiles suggested ZnO NP exposure-related perturbations in signaling pathways relevant to inflammation/cell injury and corresponding biological processes, namely reactive oxygen species generation and apoptosis/necrosis, for some nanoforms, consistent with cellular oxidative stress and ATP status. The size, surface area, agglomeration state and metal contents of these ZnO nanoforms appeared to be physicochemical determinants of particle potencies. These findings warrant further research on high-content "OMICs" to validate and resolve toxicity pathways related to exposure to nanoforms to advance health risk-assessment efforts and to inform on safer materials.

Molecular docking analysis and in vivo assessment of zinc oxide nanoparticle toxicity in zebrafish larvae

The zinc oxide nanoparticles (ZnO-NPs) being widely employed in several industries and consumer products, are raising concerns about their safety on aquatic biota and human health. This study aims to investigate the possible toxicological effects of ZnO-NPs through a combined in vivo and in silico approach. Zebrafish embryos were exposed to several ZnO-NPs concentrations and morphological alterations and lipid peroxidation (MDA) were investigated. Furthermore, molecular docking simulations were applied to study the intermolecular interactions of ZnO-NPs against critical embryonic proteins namely zebrafish hatching enzyme1 (ZHE1) as well as the superoxide dismutase (SOD1). Treatment with ZnO-NPs resulted in an increase in MDA concentration and a decrease in antioxidant enzyme levels. Besides a significant decrease in mRNA expression of key enzymes of ROS detoxification genes, a modulation of inflammatory genes with a low downregulation of tnf-α, and an upregulation of il-1β were observed. Docking study suggests that the delayed hatching and increased cellular oxidative stress in zebrafish embryos may occur through a synergistic mechanism based on the ZnO-NP—dependent inhibition of ZHE1 and SOD1 enzymes. The integration of in vivo assessments with in silico computational modeling provided a more comprehensive evaluation of potential physiological risks in zebrafish embryos associated with nanomaterial exposure.

Chitosan enriched with ZnO[sbnd]nanoparticles fabricated using Synadenium glaucescens (Pax) aqueous leaf extract maintains postharvest quality of banana

Applications of edible coatings containing metallic nanoparticles for the preservation of post-harvest fruit quality have emerged as one of the most preferable strategies because of their enhanced antimicrobial properties. In the current study, zinc oxide nanoparticles were synthesized using Synadenium glaucescens leaf extract and added to chitosan for the post-harvest quality preservation of banana. The synthesized zinc oxide nanoparticles (ZnOSydlNPs) were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental dispersive x-ray (EDX) and X-ray diffraction (XRD) techniques. The nanoparticles were found to form large particles due to aggregations of small particles of an average size of 11 ± 4 nm. The coating solution containing a mixture of chitosan and zinc oxide nanoparticles exhibited higher antimicrobial effects against Escherichia coli, Staphylococcus aureus, Puccinia asparagi and Candida albicans compared to chitosan. The inhibition diameters of chitosan and chitosan-ZnOSydlNPs against E. coli were 6 and 15 mm, respectively. Similarly, the average inhibition diameters of chitosan, chitosan-ZnOSydlNPs (0.1%) and chitosan-ZnOSydlNPs (0.3%) against Staphylococcus aureus, Puccinia asparagi and Candida albicans were 10 ± 2, 15 ± 0.5 and 16 ± 3 mm, respectively. The banana coated with chitosan-ZnOSydlNPs solutions exhibited higher titratable acid (maleic) than control and chitosan-coated samples. Additionally, banana coated with chitosan-ZnOSydlNPs films showed lower total soluble solids, weight loss and ripening index compared to chitosan-coated and control samples. The findings from the current study indicated that ZnOSydlNPs incorporated in polymeric materials (chitosan) could serve as a potential preservative of post-harvest qualities for banana and related fruits.

Green Synthesis of Zinc Oxide Nanoparticles Using Dillenia Indica and Mikania Micrantha Leaf Extracts: Applications in Photocatalysis and Antibacterial Activity.

Researchers are keenly interested in developing metal-based nanoparticles using plant sources as they are eco-friendly, less expensive and simpler. Zinc oxide nanoparticles, symbolized as D-ZnONPs and M-ZnONPs were synthesized in this study utilizing the leaves of D. indica and M. micrantha, respectively, and studied their impact on the growth inhibition of various bacterial strains and on the photocatalysis. By displaying the distinctive surface plasmon resonance (SPR) band at 373 nm in UV-Vis and bands at 450-480 cm-1 corresponding to Zn-O stretching FTIR spectroscopy imparted the formation of ZnONPs which was further supported by X-ray diffraction analysis by showing the polycrystalline nature and a hexagonal wurtzite structure. The spherical form and average particle size of 30 nm of the produced ZnONPs, as confirmed by electron microscopy, are also confirmed to be crystalline. Under natural sunlight, both ZnONPs demonstrate excellent degradation efficacy about 96-99 % within 100 min towards methylene blue (MB). Furthermore, it is noteworthy that both the synthesized ZnONPs exhibited 55-60 % efficacy with respect to antibiotics in inhibiting the growth of various pathogenic bacterial strains. Overall, ZnONPs can be produced on a large-scale using plant sources and employed them in environmental remediation and cosmetic industries as prominent components.

Biogenic synthesis and characterization of antimicrobial, antioxidant, and antihemolytic zinc oxide nanoparticles from Desertifilum sp. TN-15 cell extract

Cyanobacteria, being a prominent category of phototrophic organism, exhibit substantial potential as a valuable source of bioactive compounds and phytonutrients, including liposomes, amino derivatives, proteins, and carotenoids. In this investigation, a polyphasic approach was employed to isolate and characterize a newly discovered cyanobacterial strain from a rice field in the Garh Moor district of Jhang. Desertifilum sp. TN-15, a unique and less explored cyanobacterial strain, holds significant promise as a novel candidate for the synthesis of nanoparticles. This noticeable research gap underscores the novelty and untapped potential of Desertifilum sp. TN-15 in the field of nanomedicine. The characterization of the biogenically synthesized ZnO–NPs involved the application of diverse analytical techniques. Ultraviolet–visible spectroscopy revealed a surface plasmon resonance peak at 298 nm. Fourier transform infrared spectral analysis was utilized to confirm the involvement of biomolecules in the biogenic synthesis and stability. Scanning electron microscopy was employed to probe the surface morphology of the biogenic ZnO–NPs unveiling their size of 94.80 nm and star-shaped. Furthermore, X-ray diffraction analysis substantiated the crystalline nature of ZnO–NPs, with a crystalline size measuring 46 nm. To assess the physical stability of ZnO–NPs, zeta potential and dynamic light scattering measurements were conducted, yielding values of + 31.6 mV, and 94.80 nm, respectively, indicative of favorable stability. The antibacterial capabilities of Desertifilum sp. TN-15 are attributed to its abundance of bioactive components, including proteins, liposomes, amino derivatives, and carotenoids. Through the synthesis of zinc oxide nanoparticles (ZnO–NPs) with this strain, we have effectively used these chemicals to generate nanoparticles that exhibit noteworthy antibacterial activity against Staphylococcus aureus (MIC: 30.05 ± 0.003 µg/ml). Additionally, the ZnO–NPs displayed potent antifungal activity and antioxidant properties, as well as significant antihemolytic effects on red blood cells (IC50: 4.8 µg/ml). Cytotoxicity assessment using brine shrimps revealed an IC50 value of 3.1 µg/ml. The multifaceted actions of the biogenically synthesized ZnO–NPs underscore their potential applications in pharmacological and therapeutic fields. This study proposes a novel method for ZnO–NPs production utilizing the recently identified cyanobacterial strain Desertifilum sp. TN-15, highlighting the growing significance of biological systems in the environmentally friendly fabrication of metallic oxide nanomaterials.

Synthesis, Photocatalytic and Bio Activity of ZnO-TiO2 Nanocomposites: A Review Study

Zinc oxide and titanium dioxide are materials with strong photocatalytic and antimicrobial activity. This activity is greater when the material is in nanocrystalline form. It has been seen that these properties are also present in the ZnO-TiO2 nanocomposite material, and the extent depends on multiple factors, such as crystallinity, structural composition, crystallite size, and morphology. These structural properties can be varied by acting on the synthesis of the material, obtaining a wide variety of composites: random nanoparticles, nanorods, nanowires, nanotubes, nanofibers, tetrapods, core–shell, hollow spheres, inverse opal structures (IOSs), hierarchical structures, and films. When an interface between nanocrystallites of the two oxides is created, the composite system manages to have photocatalytic activity greater than that of the two separate oxides, and in certain circumstances, even greater than P25. The antimicrobial activity results also improved for the composite system compared to the two separate oxides. These two aspects make these materials interesting in various fields, such as wastewater and air treatment, energy devices, solar filters, and pharmaceutical products and in the context of the restoration of monumental cultural assets, in which their use has a preventive purpose in the formation of biofilms. In this review we analyse the synthesis techniques of ZnO-TiO2 nanocomposites, correlating them to the shape obtained, as well as the photocatalytic and antimicrobial activity. It is also illustrated how ZnO-TiO2 nanocomposites can have a less negative impact on toxicity for humans and the environment compared to the more toxic ZnO nanoparticles or ZnO.

Synthesis of Pd-decorated ZnO nanocomposites with improved gas-sensitive properties for acetone detection

ZnO/Pd nanocomposites containing 0.5–3.0 mol.% palladium and possessing improved gas-sensitive properties for VOC’s detection were prepared using solvothermal synthesis. The synthesised powders have been characterised using various methods of physicochemical analysis (DSC/TGA, XRD, SET/TEM, XPS). It is shown that Pd@PdO nanoparticles (4–7 nm in diameter) are localised on the surface of ZnO nanoparticles (40–50 nm in size). According to the combined XRD and XPS data, it was found that palladium is in partially oxidised state, and the nanocomposite has a structure close to "core@shell": Pd@PdO. The influence of palladium concentration in the ZnO/Pd composite on the complex of chemoresistive gas-sensitive properties was studied. It is shown that at 250 °C the obtained nanocomposites demonstrate a high (up to 57.8 a.u.) response to 100 ppb–20 ppm acetone, which can be used as a part of supersensitive devices for noninvasive diagnostics of diseases.