ZnO Nanoparticles Research Articles

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.

Plant-Mediated Synthesis of Zinc Oxide (ZnO) Nanoparticles Using Alnus nepalensis D. Don for Biological Applications

An aqueous bark extract of A. nepalensis D. Don was utilized to prepare zinc oxide (ZnO) nanoparticles through a green method, which is more economical, eco-friendly, and effective for exploring several biological applications and toxicity assessments against brine shrimp nauplii. The prepared ZnO nanoparticles were characterized using several characterizing techniques. The surface morphology and the elemental composition of the prepared ZnO NPs was analyzed by field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray (EDX) analysis. The colour of the solution was changed from reddish-brown to white indicating the formation of ZnO NPs which shows UV-vis absorption at 361 nm. The various functional groups of the organic compounds present in plant extract act as reducing and stabilizing agents in the formation of nanoparticles. The involvement of these functionalities in the formation of nanoparticles is indicated by the shifts and changes in the IR spectra of both the plant extract and the ZnO nanoparticles. The size of the nanoparticles was determined to be 15.31 nm with XRD analysis while the FE-SEM revealed the average grain size of 67.29 nm with irregular shape. The elemental composition of ZnO NPs shows a greater atomic percentage of zinc compared to other elements (C, N, Ni, O, and Ag), with an intense peak of zinc observed at approximately 1 keV. The trace amount of silver is due to the impurities present in the reagent used in the experiment. The antioxidant property of ZnO nanoparticles was evaluated with an IC₅₀ of 53.02 ± 3.43 μg/mL. The ZnO nanoparticles exhibited significant antibacterial activity against Klebsiella pneumoniae and Escherichia coli, with zones of inhibition (ZOI) of 18 mm and 23 mm, respectively as compared to the positive control neomycin of ZOI 28 mm against K. pneumoniae. The potential antibacterial activity of the ZnO NPS was revealed as the MIC and MBC against K. pneumoniae of 0.39 mg/mL and 0.78 mg/mL, respectively. In addition, the prepared ZnO nanoparticles showed toxicity against brine shrimp nauplii of LC₅₀ 16.59 μg/mL. The results of this study impart that plant-assisted synthesized ZnO nanoparticles possess significant antibacterial properties that reduce oxidative stress in human cells, ultimately contributing to cancer prevention.

Fabrication and Bio-Characterization of Reinforced Glass Ionomer Cement by Zinc Oxide and Hydroxyapatite Nanoparticles

This study shows the enhancement of glass ionomer cement (GIC) by incorporating hydroxyapatite (HA) and zinc oxide (ZnO) nanoparticles to improve its mechanical strength, biological activity, and antibacterial properties. GC is widely used in dental and orthopedic applications due to its bioactivity and biocompatibility, but it suffers from weak antibacterial properties and limited load-bearing capacity. HA, a calcium phosphate compound similar to natural bone, and ZnO, known for its antibacterial and bone-regenerative properties, were integrated into GIC to address these limitations. The modified GC exhibited improved compressive strength and bioactivity, particularly with the addition of 4 wt% ZnO nanoparticles, which showed the highest increase in mechanical performance while maintaining cytocompatibility. However, the fluoride release was reduced, indicating an exchange between enhanced mechanical properties and fluoride ion release. Antibacterial efficacy was assessed using well diffusion, MIC, and MBC tests, confirming that the modified GC has significant potential in dental and orthopedic applications. Future research should focus on the long-term effects of Zn2⁺ ion release to fully understand its impact on the antibacterial performance of the cement.

Utilizing Arthrospira platensis for the fabrication of zinc oxide nanoparticles: Analysis and assessment for enhancing drought tolerance in Sub1A QTL bearing rice seedlings

In the present study, the underlying pathways for zinc oxide nanoparticles (ZnO-NPs) mediated modulation of oxidative stress under drought were evaluated in rice seedlings. Principally, rice cultivar (cv. Swarna Sub1) was used to assess the potential of the Sub1A QTL for its drought sensitivity in response to bio-fabricated ZnO-NPs. ZnO-NPs were synthesized from algal (Arthrospira platensis) extract and characterized for their opto-physical properties, confirming size (54 nm), hydrodynamicity (-18.54), amorphous-cubic shape and others features. Fifteen-day-old rice seedlings were primed with 25 ppm ZnO-NPs and exposed to 12 % polyethylene glycol (PEG) mediated drought stress (DS) for 7-days under laboratory conditions. Primarily, Sub1A QTL responded to drought-induced anoxic stress with a significant increase in the activities of alcohol dehydrogenase (447.41 %) and pyruvate decarboxylase (96.51 %) through ZnO-NPs sensitization. Plants recorded a significant reduction in root growth, which regained 89.25 % with ZnO-NPs treatments. ZnO-NPs also recovered relative water content (49 %), proline (99.2 %), and improved chlorophyll fluorescence (90.9 %) under stress. Furthermore, drought-induced membrane leakage was stabilized by reducing ionic conductivity through the distribution of wall-bound polyamines. A characteristic feature of fluorescence also reinforced the sustenance of photosynthetic activities by ZnO-NPs under drought. Alternatively, rice seedlings showed regulation of oxidative stress, where lipid peroxidation and protein carbonylation were reduced by 270 % and 178.2 %, respectively. This was observed with the minimization of superoxide and hydrogen peroxide concentrations by regulating apoplastic oxidase activity (117.64 %) with distinct polymorphisms in proteins. These observations suggest that ZnO-NPs can ameliorate drought-induced oxidative stress in rice, providing insights for improved nano-fertigation.

Impact of Zinc oxide nanoparticles on biosynthesis of Thymoquinone in cell cultures of Nigella sativa

The rising market interest for Nigella sativa (Black seeds) necessitates the development of cultivation strategies to enhance metabolites production. Zinc oxide nanoparticles (ZnO-NPs) have drawn global attention as efficient and bio safe elicitors for in vitro cultures, to enhance secondary metabolites production in medicinal plants. In this study, ZnO-NPs were utilized for establishment of callus and cell cultures in black seeds for the first time. Hypocotyl explants were cultured on Murashige and Skoog (MS) media with varying levels of ZnO-NPs, resulted in callus induction and biomass formation. Optimal response in callus growth parameters were observed when explants were grown on MS media supplemented with 60mg/L ZnO-NPs, resulting in 71.2% callus induction frequency, 28.2g/L fresh biomass, 9.7g/L dry biomass, and 63% water content. A substantial increase in callus growth was observed when ZnO-NPs were combined with 6-Benzylaminopurine (BA) at ratio of 45:1.5mg/L, resulting in 91.2% callus induction frequency and 42.2g/L fresh biomass. In cell suspension cultures, ZnO-NPs alone at 45mg/L produced optimum callus biomass (60.9g/L). However, in combination with BA, callus biomass did not increase significantly in cell cultures. Maximum accumulation of total phenolic content (TPC: 26.8mg GAE/g DW; Gallic acid equivalent dry weight) and total flavonoid content (TFC: 19.5mg QE/g DW; Quercetin equivalent dry weight) was observed in cell cultures treated with higher concentration (70mg/L) of ZnO-NPs in the 5th week of the growth curve. Moreover, ZnO-NPs incremented substantially the Phenylalanine lyase (PAL), Superoxide dismutase (SOD) and Peroxidase (POD) enzyme activities in cell cultures. Nonetheless, Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis indicated peak production of tymoquinone (168.5mg/g FW) in cell cultures treated with 45mg/L ZnO-NPs alone. This study offers a promising approach for commercial production of Nigella sativa biomass and bioactive metabolites.

Fabrication of Novel Polyurethane matrix-based Functional Composites with Enhanced Mechanical Performance

Thermoplastic polyurethane (TPU) has gained significant interest in several fields, including automobile steering wheels, and the electronics sector due to their easier processability, abrasive resistance, and self-lubricating performances. However, their strong inherent flammability and significant smoke and heat production during burning limit their industrial applications. Therefore, its applicability can be enhanced with the addition of high-strength reinforcement and making them antibacterial and flame-retardant. This research is designed to examine the influence of zirconium phosphate (ZrP) and zinc oxide (ZnO) nanoparticles on the novel polyurethane/glass fiber reinforced composites for flame retardant and antibacterial applications with improved mechanical performance. Three different types of novel polyurethane (PU1, PU2, PU3) matrices were prepared using different recipes, and 7% ZrP and 5% ZnO nanoparticles were added to the polyurethane matrices separately, and their corresponding composite samples were fabricated using glass reinforcement. Mechanical i.e., Charpy impact, hardness and tensile, and functional i.e., flame retardancy (FR) and antibacterial tests were performed to compare their performance. Mechanical testing results showed that PU3-based composite samples showed the highest values of impact force, hardness, and tensile strength in both ZrP and ZnO nanoparticle-based composite samples. Furthermore, 7% ZrP-PU3 composite exhibited the best performance of flame retardancy due to the presence of hexamethylene diisocyanates (HDI) content. Likewise, the 5% ZnO-PU3-based composite exhibited the highest antibacterial activity along with enhanced mechanical performance.

Boolean Circuits in Colloidal Mixtures of ZnO and Proteinoids.

Liquid computers use incompressible fluids for computational processes. Here, we present experimental laboratory prototypes of liquid computers using colloids composed of zinc oxide (ZnO) nanoparticles and microspheres containing thermal proteins (proteinoids). The choice of proteinoids is based on their distinctive neuron-like electrical behavior and their similarity to protocells. In addition, ZnO nanoparticles are chosen for their nontrivial electrical properties. Our research demonstrates the successful extraction of 2-, 4-, and 8-bit logic functions in ZnO proteinoid colloids. Our analysis shows that each material has a distinct set of logic functions and that the complexity of the expressions is directly related to each material present in a mixture. Our study shows that 2-, 4-, and 8-bit logic functions can be successfully extracted from ZnO proteinoid colloids. These findings provide a basis for the development of future hybrid liquid devices capable of general-purpose computing.

Efficiency of CaZn₂(OH)₆·2H₂O and ZnO nanoparticles in photocatalytic degradation of amoxicillin after multiple cycles

The widespread use of antibiotics has increased their presence in wastewater, largely due to inadequate removal by conventional treatment methods. This highlights a critical need for effective degradation strategies to mitigate environmental and public health risks. This study reports the photocatalytic degradation of amoxicillin (AMX) using calcium zinc hydroxide dihydrate [CaZn2(OH)6·2H2O] (CZ) and zinc oxide (ZnO) nanoparticles (NPs) synthesized by different routes. X-ray diffraction results confirmed the formation of CZ NPs with an 81–95% crystalline phase, while ZnO NPs present a single crystalline phase. The photolysis of AMX under UV-A light (365 nm) was strongly pH-dependent, with degradation rates of 34.7, 5.7, and 4.2% observed at pH 3, 5, and 13, respectively. Maximum adsorption occurred at pH 3, with ZnO achieving 63–83.2% AMX removal and 23.5–47.1% in the case of CZ. The highest overall AMX removal was observed at pH 3, where adsorption dominated the photocatalytic process for both CZ and ZnO. At pH 5 and 13, degradation was primarily driven by photocatalysis in CZ materials, particularly CZ-HT and CZ-SG, while adsorption remained predominant in ZnO. Proton nuclear magnetic resonance analysis indicates benzene ring cleavage in AMX photodegraded by CZ materials. Furthermore, the residues of photodegraded AMX by CZ materials lost antimicrobial activity against Gram-positive and Gram-negative bacteria. Additionally, the reuse of NPs over four cycles maintained consistent degradation performance, highlighting their potential for repeated applications. The comparative analysis of CZ and ZnO NPs superior photocatalytic efficiency of CZ in degrading AMX. This efficiency, along with its potential for repeated use, establish CZ as a promising material for environmental applications aimed at reducing antibiotic contamination and the associated risks of resistance development.

Eco-friendly drugs induce cellular changes in colistin-resistant bacteria

Abstract Background and objective As a last option, multidrug-resistant Gram-negative infections (caused by Enterobacteriaceae) are treated with the antibiotic colistin, also known as polymyxin E. Colistin-resistant superbugs predispose people to untreatable infections, possibly leading to a high mortality rate. This project aims to study the effect of Acacia nilotica aqueous extract and zinc oxide nanoparticles (ZnO-NPs) on colistin-resistant Klebsiella pneumonia (CRKP). Materials and methods ZnO-NPs were synthesized using the green method and characterized by UV-vis, Fourier transform infrared spectroscopy, and X-ray diffraction. The zone of inhibition (ZI) was measured using the agar-well diffusion method, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration were estimated to determine the antimicrobial activity of the tested compound. Scanning electron microscopy (SEM) and transmission electronic microscopy (TEM) were used to investigate the alterations in bacterial cells that were treated with the tested drugs. Results The synthesized ZnO-NPs presented good chemical and physical properties, and the plant extract and ZnO-NPs displayed a large ZI. ZnO-NPs had the lowest MIC (0.2 mg·mL−1). SEM and TEM observations revealed various morphological modifications in CRKP cells, including cell shrinkage, cell damage, cytoplasm loss, cell wall thinning, and cell death. Conclusion A. nilotica aqueous extract and ZnO-NPs could be used as alternative natural products to produce antibacterial drugs and to prevent CRKP infection.

Amelioration of Full-Thickness Cutaneous Wound Healing Using Stem Cell Exosome and Zinc Oxide Nanoparticles in Rats

BackgroundWound healing is a complex procedure that requires the coordination of several factors, so this study aimed to assess the zinc oxide nanoparticles’ regenerated effect and stem cell exosomes on full-thickness wounds in rats. MethodsSeventy-two Wistar male rats were subjected to a full-thickness skin defect (20 mm2) on the dorsal surface of each rat between two shoulder joints. The rats were randomized into four groups (18/group) according to wound treatments. The wounds were irrigated with normal saline (Control group), or the wound’s edges were subcutaneously injected daily with 0.3 ml of exosome (Exo-group), or 1 ml of zinc oxide nanoparticles (ZnO2-NPs group), or 0.3 ml of exosome in combined with 1 ml of zinc oxide nanoparticles (Exo/ZnO2-NPs group). On the 7th, 14th, and 21st days post-wounding, the weight of the rats, the wound healing breaking strength, the wound size, and the contraction percent were evaluated. Six rats in each group were euthanized at each time point for histopathological, immunohistochemical examination of collagen, the levels of alpha-smooth muscle actin (α-SMA), and epidermal growth factor receptor (EGFR). additionally, the gene expression analysis of the relative renal nuclear factor erythroid 2-related factor2 (Nrf2 mRNA), Transforming growth factor beta-1 (TGFβ1), fibroblast growth factor-7 (FGF7), Transforming growth factor beta-1 (TGFβ1), Lysyl oxidase (LOX), and Vascular endothelial growth factor (VEGF) were applied. ResultsThe Exo-group exhibited a significant decrease in wound size and a significant increase in wound contraction compared with other groups. Histopathologically evaluation during the three intervals revealed that the Exo-group had the highest collagen deposition area with a significant reduction of the granulation tissue. Moreover, upregulated gene expression profiles of the growth factors genes at all time points post-wounding. DiscussionThe exosomes-treated group revealed superior wound healing and contraction, with minimal inflammatory signs, higher angiogenesis, and myofibroblasts, and associated with higher growth factor expression genes compared to the other groups. ConclusionsExosome-based therapy demonstrates potential as a treatment method to promote and accelerate wound healing by modulating angiogenesis, re-epithelialization, collagen deposition, and gene expression profiles.

Optical properties analysis of gelatin-based prepared Co, Ni, and Mn-doped ZnO nanoparticles in infrared and UV–vis region using Kramers-Kronig methods

This study investigates the structural, optical, and morphological properties of ZnO nanoparticles doped with Ni, Mn, and Co (Zn0.97A0.03O where A = Ni, Mn, and Co, designated as ZN, ZM, and ZC, respectively). X-ray diffraction (XRD) analysis confirms the successful incorporation of dopants into the ZnO lattice without altering its wurtzite structure. Field emission scanning electron microscopy (FESEM) images reveal that doping results in larger and more uniformly distributed particles. Energy-dispersive X-ray spectroscopy (EDX) verifies the presence of Ni, Mn, and Co in the respective samples. Fourier transform infrared (FTIR) spectroscopy indicates an increase in average phonon energies due to doping, as evidenced by the shift in the Zn-O vibration peak. Ultraviolet–visible (UV–vis) spectroscopy shows that doping causes a blue shift in the absorbance peak and increases the optical band gap from 3.17 eV for pure ZnO to 3.22 eV for Co-doped ZnO. Transmission electron microscopy (TEM) and corresponding EDX results further confirm the presence of dopants and illustrate that doped ZnO nanoparticles are larger than pure ZnO particles. These findings provide valuable insights into the impact of doping on ZnO nanoparticles, potentially enhancing their suitability for various technological applications.

A Comparative Study of Congo Red Textile Dye Photodegradation Using ZnO Al and ZnO Al+Mn Nanoparticles

Photodegradation of Congo Red textile dye was successfully carried out using ZnO Al and ZnO Al+Mn nanoparticles synthesized using the bottom-up coprecipitation method. Powder X-ray diffraction provides information that Al and Mn doping successfully inserted in the host crystal structure while maintaining the Hexagonal Wurtzite crystal structure. However, a shift in the diffraction peak caused by the lattice distance changes with the addition of doping. FE-SEM EDS provides information that both nanoparticles are nonuniform sphere-like due to the addition of dopping, and each dopping is detected through EDS spectra. There is a decrease in the gap energy in each sample. ZnO Al nanoparticles have a gap energy of 3.29 eV, and ZnO Al+Mn nanoparticles have a gap energy of 3.28 eV. However, the decrease in the gap energy is not directly related to the percentage and kinetic rate of Congo Red photodegradation. Adding 5 mg of ZnO Al Nanoparticles powder could degrade Congo Red up to 97.9 % within 120 min using UV A radiation or 0.03504/min. At the same time, adding ZnO Al+Mn Nanoparticles powder with the same parameters could only degrade 67.6 % or 0.00759/min. HIGHLIGHTS Energy Bandgap Modification of ZnO Nanoparticles The incorporation of Al single dopants and Al, Mn co-dopants into ZnO nanoparticles synthesized via a bottom-up coprecipitation method significantly alters the energy bandgap. Al single doping resulted in a bandgap of 3.29 eV, while Al, Mn double doping yielded a bandgap of 3.28 eV. Enhanced Photocatalytic Activity of Al-Doped ZnO Al-doped ZnO nanoparticles exhibited superior photocatalytic activity toward the degradation of Congo Red textile dye. With a photodegradation rate constant of 0.03504 min⁻¹, these nanoparticles achieved 97.9 % degradation of Congo Red within 120 minutes. Comparative Photocatalytic Performance of Al, Mn Co-Doped ZnO While Al, Mn co-doped ZnO nanoparticles were synthesized using the same method, their photocatalytic performance for Congo Red degradation was notably lower than that of Al-doped ZnO. The calculated photodegradation rate constant was 0.00759 min⁻¹, resulting in 67.6 % degradation within the same timeframe. GRAPHICAL ABSTRACT

Sustainable Fabrication of Luminescent Zinc Oxide Nanoparticles From Cucumis melo Fruit Peel Extract as Prospective Photocatalytic and Antigermicidal Agent.

The focus of current advances in nanotechnology has shifted significantly towards environmentally conscious methods that use harmless ingredients and moderated reaction circumstances to promote equitable development. Zinc oxide nanoparticles (NPs) currently grabbed attention of multiple medical fields owing to their unique ability to safeguard against cellular damage and alleviate serious human diseases via processes related to metabolism. This work focused on the generation of ZnO NPs using the peel of Cucumis melo fruit. The NPs were then analyzed and characterized using UV-Vis spectroscopy. The results indicated that at a wavelength of 352 nm, it was proven that the biosynthesis of ZnO NPs had occurred. The XRD pattern indicated the presence of dense crystal structures. The field emission scanning electron microscope (FE-SEM) picture confirmed the existence of polygonal-shaped ZnO NPs. The findings indicate that the produced ZnO NPs possess tough antibacterial properties against Gram-positive and Gram-negative microorganisms. When the ZnO NPs were exposed to direct sunshine for 80 min, they showed an 89% dye breakdown efficiency. This research specifically focused on the decomposition of reactivity dyes, with methylene blue dye being used as the target dye. The work demonstrates that the biosynthesis of ZnO NPs has a crucial and versatile role in the biological and environmental sectors.

Fabrication of Nanofiber Membranes from Waste-Expanded Polystyrene (EPS) Combined with Zinc Oxide Nanoparticles (ZnO NPs) and its Photocatalytic Activity

Society must face the challenge of creating high-value products from recycled waste polymers. This research focuses on the synthesis of nanofiber membranes from waste-expanded polystyrene (EPS) using electrospinning. Zinc oxide nanoparticles (ZnO NPs) enhance the photocatalytic activity of the fiber membrane. ZnO is a more useful alternative to TiO2 as a form of photocatalyst for degrading contaminants in water. This study systematically investigated the effects of varying amounts of ZnO NPs on fiber membrane nanostructure and photocatalytic activity. Methylene blue was used to measure the photocatalytic efficiency of fiber membranes, as they are commonly used in textile wastewater and exposed to ultraviolet light for 20 h. The results showed that the fiber membrane containing ZnO NPs with a concentration of 1 % effectively degraded methylene blue. HIGHLIGHTS The EPS/ZnO nanofiber produced using electrospinning was characterized using SEM-EDX, FTIR, and Raman spectroscopy UV-Vis spectrophotometer testing proves that the EPS/ZnO nanofiber has photocatalytic activity capabilities that can remove organic contaminants The EPS/ZnO 1 % shows the highest efficiency; 45 % of methylene blue was degraded within 20 h of irradiation GRAPHICAL ABSTRACT

Green synthesis of bimetallic Ag-ZnO nanocomposite using polyherbal extract for antibacterial and anti-inflammatory activity

The current research has involved to develop nanoparticles (NPs) of zinc oxide (ZnO) doped with silver (Ag) through an eco-friendly method. Eclipta prostrate (EP), Eclipta alba (EA), and Tridax procumbans (TP) are subjected to Soxhlet extraction using ethyl acetate. Alkaloids, flavonoids, and phenols were quantified using standard methods. Polyherbal extract was used to synthesize silver-zinc oxide nanocomposites (Ag-ZnO NCs) via the sol-gel method. The reduction of metal ions was confirmed by UV–visible spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Polyherbal plants are found to have higher concentrations of phenols, flavonoids, and alkaloids than indigenous plants. Ag-ZnO NCs functional group has been identified using Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. UV–vis spectroscopy revealed the surface plasmon resonance (SPR) of silver nanoparticles at 463–477 nm and zinc oxide nanoparticles at 266–267 nm. For Ag-ZnO NCs, the SPR peak was observed at 450 nm. Scanning electron microscopy confirmed the spherical morphology of the Ag-ZnO NCs. The anti-microbial activity of the formulated Ag-ZnO NCs was more effective than the extract against all tested pathogens. The most effective antimicrobial activities are achieved for Ag-ZnO NCs at 50 µg and 200 µg for extract. Biosynthesized nanoparticles exhibit a significant anti-inflammatory effect of 68% at a low concentration of 500 µg/mL, greater than the efficacy of diclofenac sodium. Additionally, the synthesized Ag-ZnO nanoparticle demonstrated its stability for 90 days and showed strong antimicrobial properties.

Investigating the in vitro antibacterial, antibiofilm, antioxidant, anticancer and antiviral activities of zinc oxide nanoparticles biofabricated from Cassia javanica.

It is thought to be risk-free, environmentally benign, and safe for biological processes to produce zinc oxide nanoparticles from renewable resources. This study examined Cassia javanica's ability to create ZnONPs. The generated ZnONPs were analyzed using a variety of techniques, such as TEM, FTIR spectroscopy, UV-Vis spectroscopy, and XRD analysis. The antibacterial potential of ZnONPs has been investigated using both Agar well diffusion and microtitreplate (MTP) methods. One method used to evaluate ZnONPs' capacity to scavenge free radicals at different concentrations was the DPPH method. The permanent zinc oxide (ZnO) shape and the naturally occurring crystal structure of ZnONPs were validated by the XRD data. ZnONPs showed antibacterial activity with MICs of 31.7 μg/mL toward Bacillus subtilis, 62.5 μg/mL for Salmonella typhimurium, Escherichia coli while Clostridium sporogenes and Bacillus pumilus was 125μg/mL. Furthermore, ZnONPs demonstrated a range of antibiofilm activities toward Staphylococcus aureus (MRSA). ZnONPs showed an intriguing antioxidant capacity, achieving IC50 of 109.3 μg/ml μg/mL. Additionally, ZnONPs demonstrated low toxic effect on Vero cell with IC50 154.01 μg/mL as well as possible anticancer action when applied to the carcinoma cell lines HepG2 with IC50 of 47.48 μg/mL. Furthermore, ZnONPs at 62.5 μg/mL had a promising antiviral impact against HSV1 and COX B4, with antiviral activities of 75.4% and 65.8%, respectively.