ZnO Nanoparticles Research Articles

Sol-gel synthesis, characterizations of efficient Y3+ doped ZnO nanoparticles for photocatalytic dye degradation and energy storage applications

Sol-gel synthesis, characterizations of efficient Y3+ doped ZnO nanoparticles for photocatalytic dye degradation and energy storage applications

Exploring the photocatalytic breakdown of organic pollutants using intercalated ZnO/SiO2 nanocomposites

The increasing prevalence of organic pollutants in water sources necessitates the development of efficient and cost-effective photocatalysts for their degradation. ZnO nanoparticles (NPs) have been widely studied for their photocatalytic properties; however, their application is hindered by low photocatalytic efficiency and high recombination rates of photogenerated carriers. This manuscript explores the enhanced photocatalytic performance of intercalated ZnO/SiO2 nanocomposites (NCs), synthesized through a combination of co-precipitation and Stöber methods, as a solution to these challenges. A comprehensive analysis of the structural, optical elemental and Morphological properties of both ZnO NPs and ZnO/SiO2 NCs was conducted using various characterization techniques, including X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV–Vis spectrometry and Brunauer-Emmett-Teller (BET) analysis. Through, XRD analysis, the calculated crystallite sizes of ZnO NPs and ZnO/SiO₂ NCs were found to be 36 nm and 39 nm respectively. TEM images illustrated that the ZnO NPs and ZnO/SiO₂ NCs have crystallized in elongated spherical morphology. XPS and FTIR analyses provided the signature band details the presence of Cu and Si in their Zn2⁺ and Si⁴⁺ oxidation states. The optical bandgap energies were calculated to be 3.38 eV for ZnO NPs and 3.22 eV for ZnO/SiO₂ NCs. The enhanced photocatalytic efficiency of the ZnO/SiO2 NCs achieved an impressive degradation rate of 92 % for Rhodamine B (RhB), compared to a relatively lower rate of 81 % for pure ZnO NPs for the degradation of RhB under visible light due to its lower bandgap, high surface area, and lower electron-hole recombination rate. BET surface area measurements revealed that ZnO nanoparticles have a surface area of 11.234 m2/g, while ZnO/SiO₂ NCs show 57.118 m2/g, highlighting SiO₂'s enhancement. The NCs demonstrated exceptional reusability for degradation, sustaining high efficiency across multiple cycles. Its ability to scavenge superoxide radicals highlighted the effectiveness of the ZnO/SiO₂ NCs in environmental remediation, especially for wastewater treatment.

Bioactive electrospun zein fibers integrated with ZnO nanoparticles: In vitro investigations

The objective of the current study was the fabrication and characterization of electrospun zein-ZnO fibers containing various concentrations of cumin essential oil (CEO) (0, 1, 2, and 3% (v/v)). The electrospinning solution's apparent viscosity, conductivity, and surface tension were measured. Also, the electrospun's morphological, color, encapsulation efficiency, antioxidant and antimicrobial properties, thermal stability, and release kinetic were investigated. The results represented that following the increase in CEO concentration, the conductivity and surface tension of the electrospinning solution changed from 182.92 μS/cm to 145.22 μS/cm and 19.52 mN/m to 22.35 mN/m, respectively. The scanning electron microscope (SEM) revealed the homogenous and free-bead structure of electrospun fibers. Besides, the diameter of fibers enhanced with a rise in CEO concentration from 217.13 nm to 321.67 nm. The finding estimated the maximum encapsulation efficiency and loading capacity at about 95.09% and 25.65%, respectively in electrospun containing the highest concentration of CEO (3%). CEO inclusion in electrospinning fibers augmented the value of contact angle, color difference, TPC, antioxidant, and antimicrobial properties. The favorable interaction between the CEO ingredients and electrospinning fibers was confirmed through FTIR and XRD analysis. Furthermore, the incorption of CEO enhanced the thermal stability of fibers. Release kinetic in different simulant (aqueous, acidic, alkaline, and fatty) revealed that Fick's diffusion was the main release mechanism. The highest diffusion coefficient was observed in electrospun fibers containing 3% CEO in the fatty media simulant. These findings could present a new horizon into electrospinning fiber's application in various fields of medicine, tissue engineering, food, and pharmaceutical industry.

Tobacco stem extract-mediated green synthesis of Fe-doped ZnO nanoparticles towards enhanced photocatalytic degradation of methylene blue and solar cell efficiency

Tobacco stem extract-mediated green synthesis of Fe-doped ZnO nanoparticles towards enhanced photocatalytic degradation of methylene blue and solar cell efficiency

Zinc Oxide Nanoparticles Treatment Maintains the Postharvest Quality of Litchi Fruit by Inducing Antioxidant Capacity

Pericarp browning and fruit decay severely reduce the postharvest quality of litchi. Improving the antioxidant capacity of the fruit is an effective way to solve these problems. In our study, the appropriate zinc oxide nanoparticles (ZnO NPs) treatment and its mechanism of action on the storability of litchi was investigated. Litchi fruit was soaked in a 100 mg·L−1 ZnO NPs suspension, water, and 500 mg·L−1 prochloraz for 2 min, respectively. The results showed that the ZnO NPs treatment delayed pericarp browning and decay in litchi fruit and was more effective than prochloraz treatment. The ZnO NPs-treated fruit showed significantly increased contents of total anthocyanin, total phenols, and activities of DPPH scavenging, superoxide dismutase, and glutathione peroxidase, as well as the lowest activities of polyphenol oxidase and laccase. ZnO NPs generated hydrogen peroxide and superoxide anion radicals, which were beneficial in slowing down the decay and inducing antioxidant capacity. However, these reactive oxygen species also consumed catalase, peroxidase, glutathione, and glutathione peroxidase. This means that litchi should be treated with an appropriate concentration of ZnO NPs. We concluded that treatment with a 100 mg·L−1 ZnO NPs suspension could induce antioxidant capacity, which is a promising and effective method to maintain the postharvest quality of litchi.

Antimicrobial Effect of Zinc Oxide Nanoparticle Coating on Titanium 6 Aluminum 4 Vanadium (Ti-6Al-4V)-Fixed Orthodontic Retainer Substrate

Abstract Objectives Due to its excellent biocompatibility, superior mechanical qualities, and exceptional corrosion resistance, titanium 6 aluminum 4 vanadium (Ti-6Al-4V) alloy is frequently used for medical and orthodontic purposes as a fixed retainer after active orthodontic treatment. Titanium lacks the antibacterial characteristics and is bioinert, this may influence the usage of such materials in the field of biomedical applications. Bacterial adhesion to the orthodontic retainer surface is a common first step in infection; this is followed by bacterial colonization ending with the formation of a biofilm. Once biofilm forms, it is highly resistant to medicines and the host immune system's defense mechanism, making it difficult to remove the biofilm from orthodontic retainer. This study aimed to test the antimicrobial effect of a zinc oxide (ZnO) nanoparticle coating on Ti-6Al-4V orthodontic retainers. Materials and Methods ZnO nanoparticles, with a particle size of 10 to 30 nm, were used to coat the alloy using the electrophoretic deposition method. Various parameters and surface characterization tests were employed to obtain an optimized sample. This sample was subjected to the microbial adherence optical density test to examine the adherence of Streptococcus mutans, Lactobacillus acidophilus bacteria, and Candida albicans. Results The optimized sample had a 5-mg/L ZnO concentration, applied voltage of 50 V, and a 1-cm distance between electrodes. The ZnO coating significantly reduced microbial adherence compared to uncoated samples, effectively inhibiting bacterial development. Conclusion Electrophoretic deposition is an efficient and cost-effective technique for coating orthodontic titanium retainer substrates. Coating Ti-6Al-4V with ZnO nanoparticles increased the antimicrobial effectiveness of the material and as the concentration of the nanoparticles rises, the antimicrobial effect increases too.

Investigating antioxidant effects of hamamelitannin-conjugated zinc oxide nanoparticles on oxidative stress-Induced neurotoxicity in zebrafish larvae model.

An excessive amount of reactive oxygen species triggers oxidative stress, leading to an imbalance in cellular homeostasis. Antioxidant therapy is an effective tool for lowering the oxidative stress and associated ailments. Recently, green nano-based drug formulations have demonstrated promising antioxidant activity and neutralizing oxidative stress. In this study, a tannin molecule Hamamelitannin (HAM), was utilized to synthesize zinc oxide nanoparticles HAM-ZnO NPs, to mitigate oxidative stress and associated ailments . The HAM-ZnO NPs were synthesized and characterized by XRD, SEM, and FTIR. The antioxidant potentials of HAM-ZnO NPs were analyzed by in vitro antioxidant assays. Zebrafish embryos and larvae were used as in-vivo models to assess the toxicity and antioxidant protective mechanism. Hydrogen peroxide (1mM) was employed to induce oxidative stress and treated with HAM-ZnO NPs to study the cognitive impairment and antioxidant enzyme levels. Levels of reactive oxygen species and cell death due to oxidative stress induction were studied by 2',7'-dichlorodihydrofluorescein diacetate and Acridine orange staining methods. Additionally, expression of Antioxidant genes such as SOD, CAT, GPx, and GSR were studied. . HAM-ZnO NPs exhibited a spherical morphology and size ranges between 48 and 53nm. In vitro antioxidant studies revealed the antioxidant properties of HAM-ZnO NPs. Furthermore, in vivo studies indicated that HAM-ZnO NPs don't possess any cytotoxic effects in zebrafish larvae at concentrations between (5-25µg/ml), The study also observed that HAM-ZnO NPs significantly reduced Hydrogen Peroxide-induced stress and increased antioxidant activity in zebrafish larvae. Also, the antioxidant gene expression was upregulated in the HAM-ZnO NPs zebrafish larvae. Findings in this study showed that HAM-ZnO NPs might be a potential intervention for diseases linked to oxidative stress.

Recent Advances in Zinc Oxide Nanoparticles: Synthesis Methods, Characterization Techniques, and Emerging Applications

Abstract: Zinc oxide (ZnO) is an inorganic compound with unique physicochemical characteris-tics that make it versatile and suitable for various applications, especially in the form of nanoparti-cles (NPs). ZnO nanoparticles (ZnO NPs) exhibit distinct properties and are produced through diverse techniques, making them valuable for applications ranging from consumer goods to medi-cal and catalytic uses. The increasing popularity of ZnO NPs is driven by novel synthesis methods that allow for modification of chemical composition and control over size and shape, thereby en-hancing their properties and expanding their applications. The catalytic activity of ZnO NPs is influenced by parameters such as oxophilicity, large surface area, amphoteric nature, and the zinc cation's ability to approach activated starting material supports, making them viable heterogeneous catalysts for a variety of applications. Various analytical techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis, atomic force microscopy (AFM), and many more, are used to characterize the nanoparticles. This article explores various synthesis methods and characterization techniques and focuses on the catalytic activities of ZnO NPs

Laser Treatment Effect on Fatigue Characterizations for Steel Alloy Beam Coated with Nanoparticles

Previous work investigated the effect of nano coating for steel beams on the fatigue characterization and calculated that the coating for beams leads to modifying the fatiguelife and stress. Therefore, this work modifies the fatigue characterizations for beams by using laser treatment. The main aim of this work is to modify the fatigue properties of steel materials by using a coating surface, with nanoparticle materials, in addition to the laser treatment technique, at the same time. The experimental work was divided into three parts; first, the fabricated fatigue steel samples were coated by zinc oxide (ZnO) nanoparticle; second, treatment of the fatigue sample by laser technique using (low-high) and (high–low) loading; and finally, testing the fatigue samples to calculate the fatigue life and stress, with and without laser treatment. A scanning electron microscope (SEM) was used to study the surface morphology of the samples. In addition, the numerical technique, using the finite element, was employed to evaluate the fatigue characterizations for steel samples and the results were compared. The comparison of the numerical and experimental results shows that the maximum discrepancy did not exceed about 10.86%. Finally, the treatment of nanomaterials coated steel samples shows that the fatigue characterizations were more than 35%.

Nanostructured defects-rich black-ZnO/biowaste-derived carbon composites for efficient visible light-driven hydrogen generation: A study on the role of C–Zn@C–O–Zn interface

The use of a highly efficient and noble-metal-free cocatalyst, which is being pursued to create hydrogen (H2) via photocatalysis, has been the subject of many studies. In this work, a unique ultrasonication-assisted laser beam irradiation process is employed to synthesize a new carbon material generated from pineapple peel biowaste (ppC) and mix it with oxygen-deficient black zinc oxide (b-ZnOvac) nanoparticles. In the ppCx@b-ZnOvac nanostructures, the XPS analysis verified the presence of surface oxygen (O2) defects and vacancies as well as chemical interactions between carbon and zinc via carbon-zinc (C–Zn) and carbon-oxygen-zinc (C–O–Zn) connection interfaces. Following optimization, the visible light active photocatalytic H2 production rate of the ppC10@b-ZnOvac nanostructures reached 215.92 μmol h−1 g−1, which was the highest. The positive synergistic interaction between b-ZnOvac and ppC is responsible for the significant increase in the rate of H2 generation. Furthermore, the significant chemical bond between ppC and b-ZnOvac via the C–Zn/C–O–Zn interface, as well as the development of surface O2 vacancy defects in b-ZnOvac, improve the efficient transfer of energetic electrons and make visible active photocatalytic H2 production from methanol in the ppCx@b-ZnOvac nanostructures easier. Our work presents a new strategy for chemically generating affordable carbon materials through the use of metal oxide-based photocatalysts with surface O2 vacancy defects and bio-waste. Applications such as water splitting, energy production, and environmental remediation show promise for these advanced materials for large-scale field applications.

Influence of Foliar Application of Nanoparticles on Low Temperature Resistance of Rice Seedlings

Chilling stress, a common abiotic factor, adversely affects the growth and biomass of rice seedlings during the early stages, ultimately reducing the yield. Effective strategies to mitigate these negative impacts are essential for improving rice productivity. The application of nanotechnology in agriculture, particularly nanoparticles (NPs), has shown a promising effect in alleviating chilling stress in plants. This study evaluates the effects of various nanoparticles, ZnO (0, 50, 100, and 200 mg/L), Fe2O3 (0, 50, 75, and 100 mg/L), TiO2 (0, 50, 75, and 100 mg/L), and CeO2 (0, 50, 75, and 100 mg/L) on the chilling resistance with one control (a water spray) under a normal temperature. Four rice cultivars: LLY-7108 and XZX-6 (Low-temperature-tolerant), and LLY-32 and ZJZ-17 (Low-temperature-susceptible) were tested in this experiment. Rice seedlings were subjected to low temperature conditions (12 h light 14 °C/12 h dark, at 10 °C) for five days, followed by seven days of recovery. The results of this study demonstrate that NPs significantly enhanced seedling height fresh/dry weight and root length compared to untreated controls under chilling stress. NP treatment also reduced the reactive oxygen species (ROS), malondialdehyde (MDA), and proline content, while enhancing superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, thereby mitigating oxidative damage. The four rice varieties exhibited clear signs of rapid growth recovery and positive physiological changes due to NPs’ application. Among the tested cultivars, LLY-7108 showed the most substantial recovery and physiological responses, while ZJZ-17 exhibited the least. The findings of this study indicate that the foliar application of ZnO (100 mg/L), Fe2O3 (50 mg/L), TiO2 (50 mg/L), and CeO2 (75 mg/L) NPs effectively mitigates chilling stress in rice seedlings, likely by enhancing the antioxidant enzymatic activity while reducing the oxidative damage. This study highlights the potential of NPs as effective agents in reducing the adverse effects of chilling stress on rice.

Optical Characteristics and Antibacterial Activity of PVA/ZnO Nanocomposites

The process of solution casting was used to create nanocomposites with different amounts of Zinc Oxide nanoparticles (0.001, 0.002, 0.003, 0.004 and 0.005)g. The structural and optical properties of PVA/ZnO nanocomposites were examined.Scanning electron microscopy (SEM) of (PVA/ZnO) nanocomposite films at 0.003 g and 0.005 g shows ZnONPs appear to form groups and disperse well; for the quantity of ZnONPs to (PVA) polymer, it forms varied shapes in specific areas inside the polymer . UV-Visible spectroscopy was utilized to measure the optical properties in the (200-900) nm wavelength range. Experiments have shown that increasing the amount of ZnONPs in nanocomposites enhances the absorbance spectrum and absorption coefficient of PVA polymer. The energy band gap of PVA polymer decreased as the amount of ZnONPs grew. In a research of the antibacterial activity of these nanocomposites, pathogen microorganisms such as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella similipneumoniae, and Candida albicans were utilized. According to the findings, the chemical nature and shape of the composites have a substantial impact on antibacterial activity, with antibacterial activity increasing as the amount of Zinc Oxide rise.

Synthesis and Characterization of ZnO Nanoparticles by Pulsed Laser Ablation in Liquid Using Different Wavelengths for Antibacterial Application

In this paper, the synthesis of colloidal solution of ZnO nanoparticles by PLAL using an Nd: YAG laser with 1064 nm and 532 nm wavelengths is described. The optical, morphological, structural, wettability and antibacterial activities were studied. The XRD analysis showed the hexagonal wurtzite structure while the UV-vis indicated the blue shift of the absorption peak due to the surface plasmon of the nanoparticle, which showed significant changes in color behavior. The FE-SEM revealed a uniformed spherical shape with a partial size range of 20.50–21.48 nm for ZnO at 1064 and 57.08–59.87 nm for ZnO at 532nm. Also, the concentration measurement indicated that the concentration of ZnO prepared at 1064 nm is 26.7 μg ml-1 and 63 μg ml-1 at 532 nm due to the relevance of high energy to the Zn plate and little distortion in the water and high absorption of short wavelength. Finally, the optical density of the antibacterial activity has been investigated, and both concentrations have good antibacterial activity at 12 h. The ZnO prepared at 532 nm has higher antibacterial activity because it has a high concentration of nanoparticles for both S. aureus and E. coli. Finally, the cell viability for ZnO synthesis with both 1064 nm and 532 nm indicates that this material has high biocompatibility and could be used for medical applications.

Shift of plasmon resonance in silver nanoparticles: effect of magnetic field pre-treatment

Abstract A novel magnetic field induced phenomenon in ZnO/Ag nanoparticles is detected and investigated with reference to the surface plasmon resonance (SPR) effect. A shift of the maximum of plasmon absorption of the ZnO/Ag nanoparticles formed in different days in magnetic field treated ZnO/ethanol solutions was observed. The observed phenomena were explained in terms of the ferromagnetic-like properties of the ZnO nanoparticles due to the surface broken bonds, which result in the appearance of non-zero magnetic moments. Magnetic field pre-treatment may be used as an effective tool for manipulating the plasmon properties of silver-based nanoparticles, which is perspective for creating new-generation sensor systems.

Green synthesis of anethole-loaded zinc oxide nanoparticles enhances antibacterial strategies against pathogenic bacteria.

The threat of antibiotic resistance is escalating, diminishing the effectiveness of numerous antibiotics due to the rapid development of resistant bacteria. In response, the use of green-synthesized nanoparticle, alone or combined with antimicrobial agents, appears promising. This study explores the effectiveness of zinc oxide nanoparticles (ZnONPs) synthesized using Loranthus cordifolius leaf extracts and subsequently coated with anethole. The fabrication of these nanoparticles was confirmed via UV-Vis, FTIR and TEM analyses, ensuring the nanoparticles were produced as intended. Utilizing a nanoprecipitation process that excludes evaporation and drying, a high drug loading capacity of 16.59% was accomplished. The encapsulation efficiency for anethole was recorded at 88.23 ± 4.98%. Antibacterial efficacy was assessed by com paring the green-synthesized ZnONPs (average size: 14.47nm), anethole-loaded ZnONPs (average size: 14,75nm), and commercially sourced ZnONPs. The ZnONPs with anethole demonstrated superior inhibition against all tested bacterial strains, including Gram-negative species like Pseudomonas aeruginosa and Escherichia coli, and Gram-positive species like Bacillus subtilis and Staphylococcus aureus, outperforming the commercially available ZnONPs. Additionally, anethole-coated ZnONPs showed the greatest inhibition of Gyr-B activity (IC50 = 0.78 ± 0.2M), better than both green-synthesized and commercially available ZnONPs. These findings emphasize the enhanced antimicrobial properties of ZnONPs, particularly when combined with green synthesis and anethole loading, highlighting their potential in various biomedical applications.

Zinc oxide nanoparticle biofortification of lentil seedlings enhances plant growth and zinc bioavailability in rats

This study aimed to evaluate the potential of zinc oxide nanoparticles (ZnO NPs) in the biofortification of lentil seedlings and subsequently improve the Zn status in rats. In the first phase of the study, the effects of various ZnO NPs concentrations (0, 10, 20, 40, 80, and 160 ppm) on the lentil growth, Zn accumulation, and other physiological parameters were investigated. Subsequently, the rats were fed ZnO NP-biofortified lentil seedlings (20 and 160 ppm) to assess their impact on animal health and Zn status. The results highlighted a concentration-dependent response of lentil seedlings to ZnO NPs, with optimal growth observed at 20 ppm, whereas higher concentrations inhibited lentil growth. Pigment and biochemical analyses revealed a complex interplay between chlorophyll, carotenoids, soluble sugars, and proteins with distinct responses to nanoparticle concentrations. Elevated levels of hydrogen peroxide and malondialdehyde of lentil seedlings at high concentrations of ZnO NPs suggest oxidative stress, countered by the upregulation of antioxidant enzymes and increased phenolic compounds. On the other hand. animal studies have showed that ZnO NP-biofortified lentil seedlings enhance serum zinc and magnesium levels in rats without affecting body weight. While serum triglyceride levels of rats decreased in both treatment groups, an elevation in creatinine and a marked increase in aspartate aminotransferase (AST) levels were observed at a higher ZnO NP concentration (160 ppm), indicative of potential kidney and liver stress. Paradoxically, serum iron levels were lower in all groups consuming lentil seedlings than in the control group, suggesting a potential interaction between lentil components and iron metabolism. These findings suggest that ZnO NP-biofortified lentils may be a promising approach to enhance Zn nutrition; however, further investigation is needed to optimize ZnO NPs concentration and assess long-term safety.

Functionalized biochar derived from novel Neolamarchia cadamba leaf extracts for the adsorption of Congo Red dye: kinetics, optimization, and reusability studies

ABSTRACT The present research emphasized on the removal of Congo Red (CR) dye from aqueous solutions using an adsorbent synthesized by utilizing the leaf extract of Neolamarchia cadamba as a bio-template. This facilitates the formation of zinc oxide nanoparticles which are then carbonized to enhance adsorption capabilities. This synthesized material is referred to as NC@ZnC, for coherent adsorption of CR dye. Various operating parameters were used for the adsorption of CR onto NC@ZnC. The maximum monolayer decontamination of CR dye was 303.03 mg/g when it was incubated for 90 min at a pH of 5. The specific surface area of amalgamated NC@ZnC was reported to be 6.509 m2/g using Bruaneur–Emmett–Teller analysis. Field-emission scanning electron microscopy was used to show the rough surface area, X-ray diffraction analysis was used to determine the crystalline structure of the adsorbent with a grain size of 20.062 nm. Elemental dispersive X-ray analysis was used to determine the elemental composition of NC@ZnC. Raman spectroscopy demonstrates a lysine group that, upon adsorption, interacts with oxygen to form a bond. NC@ZnC regresses pseudo-second-order kinetics and follows the Langmuir isotherm for the adsorption process. The sorption activity with respect to temperature appears to be displaying +ΔH° and +ΔS°, which suggests an endothermic and impulsive nature.

Multifaceted roles of zinc nanoparticles in alleviating heavy metal toxicity in plants: a comprehensive review and future perspectives.

Heavy metal (HM) toxicity is a serious concern across the globe owing to their harmful impacts on plants, animals, and humans. Zinc oxide nanoparticles (ZnO-NPs) have gained appreciable attention in mitigating the adverse effects of abiotic stresses. The exogenous application of ZnO-NPs induces tolerance against HMs by improving plant physiological, metabolic, and molecular responses. They also interact with potential osmolytes and phyto-hormones to regulate the plant performance under HM stress. Moreover, ZnO-NPs also work synergistically with microbes and gene expression which helps to withstand HM toxicity. Additionally, ZnO-NPs also restrict the uptake and accumulation of HMs in plants which improves the plant performance. This review highlights the promising role of ZnO-NPs in mitigating the adverse impacts of HMs in plants. In this review, we explained the different mechanisms mediated by ZnO-NPs to counter the toxic effects of HMs. We also discussed the interactions of ZnO-NPs with osmolytes, phytohormones, and microbes in mitigating the toxic effects of HMs in plants. This review will help to learn more about the role of ZnO-NPs to mitigate HM toxicity in plants. Therefore, it will provide new insights to ensure sustainable and safer production with ZnO-NPs in HM-polluted soils.

Salinity-responsive hyperaccumulation of flavonoids in Spirodela polyrrhiza, resultant maneuvering in the structure and antimicrobial as well as azo dye decontamination profile of biofabricated zinc oxide nanoentities.

Duckweeds (Spirodela polyrrhiza) are free-floating macrophytes that grow profusely in nutrient-rich waters. Under ideal conditions, they exhibit a rapid growth rate and can absorb a substantial amount of nutrients, macromolecules, and pollutants from bodies of water. Zinc oxide nanoparticles (ZnO NPs) synthesized from plant extracts, particularly under stress conditions, have opened new research avenues in the field of nanotechnology. Under salinity stress, the accumulation of flavonoids in duckweeds can affect the structure of ZnO NPs, helping researchers ascertain their antimicrobial role. In our study, we exposed mid-log phase duckweed monocultures to 75 mM NaCl in a full-strength Murashige and Skoog medium for 7 days, followed by a 15-day recovery period. We observed significant overexpression of superoxide and hydrogen peroxide as reactive oxygen species. As a result, chlorophyll and certain metabolites were produced in lesser amounts, while flavonoid and phenol content increased by 12% and 8%, respectively. This overproduction persisted up to 10 days into the recovery treatment period but dropped by 8% and 5%, respectively, by the 15th day. The flavonoid coating transformed the NPs into rosette clusters, which exhibited reduced antimicrobial activity against Aeromonas hydrophila, a Gram-negative, fish-pathogenic bacterium. Herein, we discuss potential mechanisms for the conformational transformation of ZnO NPs into finer dimensions in response to NaCl-induced oxidative stress in duckweed. In this study, the azo dye degradation capacity of salinity-treated plants increased as the flavonoid profile became enriched. Zinc oxide nanoparticles, both prior to and after salinity treatment, were found to be efficient in scavenging azo dye and mitigating its toxicity, as evidenced by improved germination, growth, and overall plant morphometry.

Sensitive detection of bisphenol A based on resonance energy transfer between zinc oxide nanoparticles enhanced luminol ECL and silver nanoparticles decorated TiVC MXene

This present work developed a highly sensitive electrochemiluminescence (ECL) sensor based on resonance energy transfer between ZnO nanoparticles (ZnONPs) enhanced luminol ECL as the energy donor and silver nanoparticle-modified TiVC MXene (AgNPs@TiVC) as the energy acceptor. ZnONPs were employed as catalysts to facilitate the reaction between luminol and dissolved oxygen, which could amplify the ECL signal of luminol without the need of additional co-reactants. The AgNPs@TiVC composite functioned as the energy acceptor, participating in ECL resonance energy transfer to quench the ECL emission. In the presence of bisphenol A (BPA), the specific recognition by the aptamer could detach the energy acceptor from the electrode surface, resulting in the recovery of ECL signal. The variation of ECL intensity exhibited a good linear relationship with the logarithm of BPA concentration in the range of 0.06 nM–0.08 μM, with a detection limit of 8.9 pM (3σ). This sensor owned satisfactory sensitivity and selectivity, which could further expand the utility of various MXenes in ECL sensing applications.