Metal Oxide Nanoparticles Research Articles

Bio-fabrication of zinc oxide nanoparticles from Brassica juncea (L.) Czern extract: Biological activity and DNA binding capability

Recent years have seen a great deal of interest in the exceptional biological activities such as antioxidant, antimicrobial, antiinflammation, antidiabetic and anticancer activity of various biosynthesized Metal Oxide nanoparticles. Among these metal oxide nanoparticle ZnO NPs is gaining its important in various biological applications is increasingly gain prominence. Thus, the green production of ZnO NPs using plant extract has been demonstrated as a one step, environmentally friendly and cost-effective process. This paper describes the utilization of an aqueous extract of Brassica juncea (L.) Czern seed as a reducing agent in the creation of ZnO NPs from Zinc Sulfate using a green synthesis approach. UV–visible spectroscopic peak at around 363 nm verifies the production of ZnO NPs. FE-SEM was confirmed the spherical forms of produced ZnO NPs. The average particle size of produced ZnO NPs was found to be 13.35 nm from TEM analysis. On screening the ZnO NPs for antioxidant activity it showed scavenging activity with 62.40 %, with IC50 value of 68.30 µg/mL through DPPH assay. The antidiabetic activity was found to be 72 %, with IC50 value of 71.76 μg/mL, using alpha amylase assay. In anti-inflammatory activity, the activity was recorded as 68.50 % and IC50 value as 64.67 µg/mL, using BSA denaturation assay. The synthesized nanoparticles exhibited anticancer activity against the MCF-7 and A549 cell lines. The determined IC50 value of produced ZnO NPs for these two cell lines was found to be 43.83 µg/mL and 41.48 µg/mL respectively. Additionally, a hyperchromic shift in the absorbance was noted when CT-DNA interacted with biosynthesized ZnO NPs. These findings confirm that the ZnO NPs synthesized from Brassica juncea (L.) Czern seed exhibit significant biological properties namely antioxidant, antidiabetic and cytotoxic activity. Among all these activities, the biosynthesized ZnO NPs showed excellent cytotoxic activity with the IC50 values, thus proving its effectiveness.

Advances in antibacterial activity of zinc oxide nanoparticles against Staphylococcus aureus (Review).

Nanoparticles (NPs) are one of the promising strategies to deal with bacterial infections. As the main subset of NPs, metal and metal oxide NPs show destructive power against bacteria by releasing metal ions, direct contact of cell membranes and antibiotic delivery. Recently, a number of researchers have focused on the antibacterial activity of zinc oxide nanoparticles (ZnO NPs) against Staphylococcus aureus (S. aureus). Currently, there is a lack of a comprehensive review on ZnO NPs against S. aureus. Therefore, in this review, the antibacterial activity against S. aureus of ZnO NPs made by various synthetic methods was summarized, particularly the green synthetic ZnO NPs. The synergistic antibacterial effect against S. aureus of ZnO NPs with antibiotics was also summarized. Furthermore, the present review also emphasized the enhanced activities against S. aureus of ZnO nanocomposites, nano-hybrids and functional ZnO NPs.

Synergistic Antifungal Activity of Green Synthesized Zinc Oxide Nanoparticles and Fungicide Against Rhizoctonia solani Causing Rice Sheath Blight Disease.

The biosynthesis of metal oxide nanoparticles using leaf extract of medicinal plants is a promising substitute for the traditional chemical method. This work aimed to synthesize zinc oxide nanoparticles using a green approach from local "Dholkolmi" (Ipomoea carnea) leaf extract which is a medicinal plant growing outside the roads of different regions of Bangladesh. The biosynthesized zinc oxide nanoparticles (ZnONPs) were characterized using ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, particle size analyzer, zeta-potential, scanning electron microscopy-energy dispersive spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. The results of UV-visible spectrophotometers observed an absorption peak at 373 nm wavelength, which confirmed the synthesis of ZnONPs in the solution. ZnONP sizes determined by XRD, DLS, and TEM are approximately ~37 nm, 105.61 nm, and 19.66 nm, respectively. ZnONPs were present because of the strong oxygen and zinc signals in the EDX profile. Additionally, this research assessed the antifungal activity of the biosynthesized ZnONPs and as well as folicur-incorporated ZnONPs against Rhizoctonia solani by the poison bait technique. According to the result of this study, ZnONPs synthesized from Ipomoea carnea leaf extract showed no promising result against Rhizoctonia solani mycelial growth reduction. But folicur-incorporated ZnONPs revealed a significant finding with a maximum 100% inhibition of mycelial growth at 1:1 and 3:1 ratio of ZnONPs with folicur fungicide under in vitro conditions. In the net house experiment, folicur-incorporated ZnONPs at a 1:1 ratio of ZnONPs with folicur showed considerable disease inhibition (26.96% RLH) as compared to disease control (52.83% RLH). In the case of rainfed transplanted Aus (March-June), the highest percentage of RLH was recorded in disease control (64.61%), and the lowest RLH was found in folicur (24.79%) followed by a 1:1 ratio of ZnONPs with folicur (32.10%) in field condition. On the other hand, the highest percentage of RLH was recorded in disease control (65.31%) and the lowest RLH was found in folicur (18.14%) followed by a 1:1 ratio of ZnONPs with folicur (21.39%) in rainfed transplanted Aman (July-November) season. The findings of the in vitro and in vivo studies provided evidence that ZnONPs and folicur had a strong synergistic antifungal impact and may be employed as a possible rice sheath blight disease management agent.

The green approach of chitosan/Fe2O3/ZnO-nanocomposite synthesis with an evaluation of its biological activities

Biopolymers embedded with nanoparticles of metal oxides (MOs) demonstrate a wide range of bio-functions. Chitosan-incorporated MOs are an interesting class of support matrices for enhancing the biological function, compared to other support matrices. Therefore, the importance of this study lies in exploiting chitosan as a carrier not of one metal as in previous studies, but of two metals in the form of a nanocomposite to carry out several biological functions. The coprecipitation approach was employed to synthesize chitosan/Fe2O3/ZnO-nanocomposite in the present research. The characterization of chitosan/Fe2O3/ZnO-nanocomposite was performed to find out the morphology and dispersion properties of chitosan/Fe2O3/ZnO-nanocomposite. The X-ray diffraction (XRD) investigation revealed that these were crystalline. Fourier transforms infrared (FTIR) spectrum bands were viewed at 400/cm and 900/cm, due to the stretching vibration of Fe and Zn oxygen bond. TEM showed that chitosan/Fe2O3/ZnO-nanocomposite was of 20–95 nm in size. chitosan/Fe2O3/ZnO-nanocomposite exhibited inhibitory potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Candida albicans with inhibition zones of 25 ± 0.1, 28 ± 0.2, 27 ± 0.1, and 27 ± 0.2 mm, respectively while didn’t inhibited Aspergillus niger. MIC value of nanocomposite was 15.62 ± 0.33 µg/mL for C. albicans, B. subtilis and E. coli, while it was 62.50 ± 0.66 µg/mL for Pseudomonas aeruginosa. Ranged values of nanocomposite MBC (15.62 ± 0.33 to 125 ± 1 µg/mL) were attributed to all tested bacteria. Different concentrations of chitosan/Fe2O3/ZnO-nanocomposite MBC (25, 50, and 75%) reflected anti-biofilm activity against E. coli (85.0, 93.2, and 96.0%), B. subtilis (84.88, 92.21, and 96.99%), S. aureus 81.64, 90.52, and 94.64%) and P. aurogenosa (90.11, 94.43, and 98.24%), respectively. The differences in the levels of antimicrobial activities may depend on the type of examined microbes. Antioxidant activity of chitosan/Fe2O3/ZnO-nanocomposite was recorded with excellent IC50 values of 16.06 and 32.6 µg/mL using DPPH and ABTS scavenging, respectively. Wound heal by chitosan/Fe2O3/ZnO-nanocomposite was achieved with 100% compared to the untreated cells (76.75% of wound closer). The cytotoxicity outcomes showed that the IC50 of the chitosan/Fe2O3/ZnO-nanocomposite was 564.32 ± 1.46 µg/mL normal WI-38 cells. Based on the achieved findings, the chitosan/Fe2O3/ZnO-nanocomposite is a very promising agent for perform pharmacological activities.

Engineered hybrid iron‐cobalt metal oxide nanoparticles for effective adsorption of malachite green dye

AbstractBACKGROUNDHybrid iron and cobalt metal oxide nanoparticles are well known; however, are not optimized in terms of size and stability. We engineered these hybrid nanoparticles using the co‐precipitation method and characterized them by various techniques, which are then used for the effective adsorption and removal of malachite green (MG) dye.RESULTSThe ideal conditions for synthesis are determined to be 50:50 ratio of Fe2O3 and CoO, pH of 11, temperature range of 40 °C–60 °C, and reactant addition time of 20 min. These hybrid nanoadsorbents effectively eliminated MG dye from aqueous solutions. Factors such as initial MG dye concentration, pH of the medium, contact time, temperature, and nanoadsorbent dose were optimized for the MG removal to achieve a maximum removal efficiency of 96.9%. Non‐linear fitting of data indicates that both Langmuir and Freundlich models provided the best fit, suggesting the presence of both monolayer and multilayer adsorption of MG on hybrid nanoparticles. The kinetics of MG dye removal are better controlled by the intraparticle diffusion (IPD) phenomenon. The adsorption of MG onto the hybrid nanoparticles was confirmed to be endothermic, with negative ΔG and positive ΔH values. The optimized synthetic conditions also positively impacted the hybrid nanoparticles which enhanced the adsorption and exhibited ferromagnetic behavior as compared to the superparamagnetic behavior reported in the literature, making them significantly important for dye removal applications.CONCLUSIONThese findings demonstrate the potential of optimized hybrid nanoparticles as effective nanoadsorbents for dye removal applications, with implications for further applications in photocatalysis and sensing. © 2024 Society of Chemical Industry (SCI).

Investigation the Influence of Calcination Temperature on Structural, Electrical and Gas Sensing Properties MnO<sub>2</sub> Thick Films

Metal oxide nanoparticles are widely used in various fields, including catalysis, sensing, energy storage, and more. Manganese dioxide (MnO2) is a promising material for gas sensors due to its sensitivity to various gases, including oxidizing and reducing gases. The calcination temperature affects their size, crystallinity, surface area, and other properties. In the present research work, the influence of calcination temperature on the structural, electrical and gas sensing properties of MnO2 nanoparticles or nanopowders was investigated. The MnO2 nanopowder was calcinated at 200, 400, 600, and 800 °C in a muffle furnace for 4 hours. After that, using the calcinated powder of MnO2, the thick films were prepared using the standard screen printing technique. The structural characterizations were investigated using SEM, EDS, and XRD. It has been found that as the calcination temperature is increased, the electrical, structural, and gas-sensing properties of MnO2 change. The prepared thick films calcinated at 200, 400, 600, and 800 °C are labeled as samples 1, 2, 3, and 4, respectively, in this paper. It has been found that sample 4 shows maximum resistivity, a more specific surface area, a smaller crystallite, and a maximum gas response to H2S gas. The maximum sensitivity was found to be 76.32% to H2S gas at operating temperature 120 °C. The response and recovery time was also found quickly.

Effect the Nanoparticles of Fe2O3 and CuO to Increasing the Activity of Sulfadiazine Against Multidrug Resistant Pseudomonas Aeruginosa

General Background: Antibiotic resistance is a critical global health issue, and innovative approaches are needed to combat multidrug-resistant (MDR) bacteria. Specific Background: Nanotechnology has emerged as a promising strategy to enhance antibiotic efficacy and reduce resistance. Knowledge Gap: However, there is limited understanding of how metal oxide nanoparticles (NPs) like Fe2O3 and CuO can be utilized to improve the performance of antibiotics such as sulfadiazine. Aims: This study aimed to synthesize Fe2O3 and CuO nanoparticles, conjugate them with sulfadiazine, and evaluate their antibacterial efficacy against MDR Pseudomonas aeruginosa. Results: The nanoparticles were synthesized via chemical precipitation, with Fe2O3 and CuO having mean crystal sizes of 41.40 nm and 44.83 nm, respectively. When bound to sulfadiazine, the crystal sizes were 42.62 nm (Fe2O3) and 38.77 nm (CuO). The minimum inhibitory concentration (MIC) values for sulfadiazine-bound CuO and Fe2O3 NPs ranged from 16-32 μg/ml, significantly lower than the 64-128 μg/ml observed for standard sulfadiazine. Hemolysis assays confirmed the biocompatibility of these nanocomposites at tested concentrations. Novelty: The study reveals that Fe2O3 and CuO nanoparticles significantly enhance sulfadiazine's antibacterial activity against MDR P. aeruginosa, suggesting a potential method to bypass traditional resistance mechanisms. Implications: The study suggests that nanoparticle-conjugated antibiotics could be a promising solution for combating antibiotic resistance, potentially reducing its negative impact on public health. Highlights: Nanoparticles reduce sulfadiazine's MIC against MDR Pseudomonas aeruginosa. Fe2O3 and CuO nanoparticles enhance antibiotic efficacy. Hemolysis assays confirm nanocomposites' safety and biocompatibility. Keywords: Nanotechnology, Antibiotic Resistance, Fe2O3 Nanoparticles, CuO Nanoparticles, MDR Pseudomonas aeruginosa

Metal and Metal Oxide Nanoparticles and Synergistic Therapy as A Novel Method for Managing Diabetic Nephropathy: A Brief Overview

Metal and Metal Oxide Nanoparticles and Synergistic Therapy as A Novel Method for Managing Diabetic Nephropathy: A Brief Overview

Tailoring photocatalytic performance: Lanthanum doping in nickel oxide for efficient degradation of some industrial cationic dyes in visible light radiation

Metal oxide nanoparticles have emerged as an important component in heterogeneous photocatalysis, which uses light-induced reactions on the surface of a catalyst to drive chemical transformations. The improved photocatalytic activity of lanthanum-doped metal oxide nanoparticles has been the subject of research due to their special qualities, which include enhanced photocatalytic performance, stability and absorption of visible light. This study involves co-precipitation approach to synthesize nickel oxide nanoparticles and nickel oxide nanoparticles doped with lanthanum. The nanoparticles were determined using UV-Visible absorption spectrophotometry, X-ray diffraction spectroscopy, Energy-disperse spectroscopy, Photoluminescence spectroscopy and Field emission scanning electron microscopy. For the photodegradation of malachite green and rhodamine B dyes, synthesized nanoparticles were employed as photocatalysts. Compared to pure NiO, the photochemical activity of 4 % Lanthanum-doped NiO was higher. The degrading efficiency of 4 % La-doped NiO is 89 % effective towards rhodamine B and 87 % for malachite green. In addition, entrapment was done to identify primary active species responsible for photocatalytic activity. The present study likely provides new insights and novelty into the photocatalytic mechanisms at play, including how lanthanum doping affects the generation and dynamics of reactive oxygen species (ROS) like hydroxyl radicals and superoxide anions, which are responsible for the breakdown of dye molecules.

Green Synthesis of Iron Nanoparticles (FeNPs) using Aqueous Extract of Murraya koenigii Leaves: Synthesis Mechanism, Characterization Process and Antibacterial Activity

Introduction: Green synthesis is the method of producing metal and metal oxide nanoparticles from the extraction of plant materials. This study aims to synthesize iron nanoparticles (FeNPs) using an aqueous extract of Murraya koenigii leaves as an eco-friendly approach and subsequently characterize the synthesized FeNPs to understand their structural, morphological, compositional and optical properties. Methods: The aqueous extract of Murraya koenigii leaves and 0.1M ferric chloride solution were combined at room temperature in a 1:2 volume ratio. The synthesized FeNPs were characterized using analysis methods of Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), UV-visible (UV-vis) and Tacu plot. Results: SEM images discovered that the particles were in the nanoscale range and their morphology appeared spherical shape. The EDX study was used to identify the composition of the elements of synthesized FeNPs. The crystal structure of the synthesised FeNPs was shown in the XRD spectrum. The FTIR spectrum showed many distinctive bands and the bands revealed active components for functional groups in the synthesized FeNPs. The UV-vis spectrum revealed an absorbance peak range of 240-310 nm for FeNP formation with a maximal peak at 273 nm. The band gap energy of the synthesized FeNPs was found to be 2.07 eV using the Tauc plot method. Also, the synthesized FeNPs exhibited a significant antibacterial effect against bacterial pathogens. Conclusion: The results of the characterization methods strongly suggest that the aqueous leaf extract of Murraya koenigii can be used as a reducing and stabilizing agent in the green synthesis of FeNPs.

Synthesis, Structural, and Optical Properties of Modified Poly(vinyl Chloride) Thin Films by Ethylenediamine Loaded with Metal Oxide Nanoparticles

AbstractPoly (vinyl chloride) (PVC) films modified with ethylenediamine (en) and doped by nanoparticles (TiO2, ZnO, NiO, and MgO). A mixture of 0.5 g PVC/en dissolved in THF and 0.01 wt % of nanoparticles were used in doping PVC to produce the nanocomposite films. All modified PVC films were characterized by different analysis techniques such as Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance Spectrometer (NMR), diffusive reflectance spectroscopy (DRS), X‐ray diffraction analysis (XRD), and scanning electron microscopy (SEM). The DRS was used to analyse the scattered IR energy of the samples at wavelengths between (250–1350 nm). The optical properties and oscillator strength were also studied, the transmittance and reflectance values declined for the PVC films, and the absorption coefficient was observed between (79–89 %). The direct energy gap decreased from 4.6 to 1.9, and the indirect energy gap reduced from 4.3 to 1.9. The XRD exhibited a semi‐crystalline structure and the SEM test exhibited a porous structure of all samples. The Urbach energy was increased from 0.8772 eV to 14.712 eV, single oscillator energy ( ) was also increased from 6.38 eV to 13.69 eV and the dispersion energy increased from 23.40 eV to 70.63 eV. Moreover, the surface roughness parameters Ra and Rq of the PVC films in modified and doping were increased from 3.86 nm to 8.14 nm, and 5.08 nm to 10.10 nm respectively. So, PVC results show increased optical properties after modification with en and doping by NPs are used in the light conversion and aerospace industries.

Synthesis, dispersion, functionalization, biological and antioxidant activity of metal oxide nanoparticles: Review

Metal oxide nanoparticles (MONPs) have garnered significant interest due to their remarkable properties with applications in diverse fields like human health, agriculture, and general community health. This has led to their widespread use across various scientific and industrial sectors. We focused on four specific types of MONPs: iron oxide, gadolinium oxide, titanium dioxide, and zinc oxide nanoparticles due to their advantages over other metal oxides and noble metals, including cost-effectiveness, biocompatibility, and versatility. This review aimed to highlight examples of MONPs with various implementations and provide a comprehensive revision on the synthesis, dispersion, functionalization, biological and antioxidant activity of the selected MONPs. In this context, we demonstrated the applications of MONPs in various relevant domains and the impact of surface functionalization on the mechanical, optical, and electrical properties of MONPs, particularly in biological and antioxidant activities. Moreover, the volumetric, viscometric, and optical characteristics of MONPs dispersions and their stability challenges were significantly illustrated. The opportunities for MONPs in the global market based on market statistical studies were introduced in order to explore the current and future prospects for MONPs in the commercial market. This review paper offers a thorough and novel perspective on the synthesis, properties, functionalization, and applications of selected MONPs, along with their market potential, making it a valuable resource for researchers and industry professionals. Our revision has sparked interest in the scientific pursuit of uncomplicated and intuitive ideas that make use of regenerative options.

Tuning the optical properties of PMMA polymer by using subphthalocyanine dye and metal oxide nanoparticles for flexible optoelectronic devices

Tuning the optical properties of PMMA polymer by using subphthalocyanine dye and metal oxide nanoparticles for flexible optoelectronic devices

Piper chaba Stem Extract Assisted Facile Synthesis of Zinc Oxide Nanoparticles for Photocatalytic and Antimicrobial Applications

ABSTRACTThe versatile application of metal‐based nanoparticles has led to a recent rise in interest in the low‐cost and eco‐friendly green chemistry‐based development of metal oxide nanoparticles. This work focuses on the photocatalytic and antibacterial uses of the zinc oxide nanoparticles (ZnONPs) that were produced based on a green approach employing stem extract of Piper chaba. The formation of ZnONPs was preliminary validated by the appearance of an absorption band at 373 nm and a stretching band due to ZnO at 480 cm−1 in UV–Vis and FTIR spectrum, respectively. The crystalline nature of ZnONPs with a hexagonal wurtzite phase and an average crystallite size of 25 nm was validated by XRD analysis. ZnONPs' crystalline nature was further supported by TEM, which further showed that they were mostly cubic in form and had an average length of 30 nm. Synthesized ZnONPs demonstrated significant antibacterial activity against Salmonella typhi, Vibrio cholerae, Escherichia coli, and Staphylococcus aureus and lucrative photocatalytic activity with the rate constant value of 0.0273 min−1 towards the degradation of methylene blue under sunlight exposure. Therefore, a facile, affordable, and ecologically sustainable method like this might be used for the large‐scale synthesis of ZnONPs.

Ultrasound-assisted water oxidation: unveiling the role of piezoelectric metal-oxide sonocatalysts for cancer treatment

Ultrasound radiation has been widely used in biomedical application for both diagnosis and therapy. Metal oxides nanoparticles (NPs), like ZnO or TiO2 NPs, have been widely demonstrated to act as excellent sonocatalysts and significantly enhance cavitation at their surface, making them optimal for sonodynamic cancer therapy. These NPs often possess semiconductive and piezoelectric properties that contribute to the complex phenomena occurring at the water-oxide interface during sonostimulation. Despite the great potential in applied sonocatalysis and water splitting, the complex mechanism that governs the phenomenon is still a research subject. This work investigates the role of piezoelectric ZnO micro- and nano-particles in ultrasound-assisted water oxidation. Three metal oxides presenting fundamental electronic and mechanical differences are evaluated in terms of ultrasound-triggered reactive oxygen species generation in aqueous media: electromechanically inert SiO2 NPs, semiconducting TiO2 NPs, piezoelectric and semiconducting ZnO micro- and nanoparticles with different surface areas and sizes. The presence of silver ions in the aqueous solution was further considered to impart a potential electron scavenging effects and better evaluate the oxygen generation performances of the different structures. Following sonoirradiation, the particles are optically and chemically analyzed to study the effect of sonostimulation at their surface. The production of gaseous molecular oxygen is measured, revealing the potential of piezoelectric particles to generate oxygen under hypoxic conditions typical of some cancer environments. Finally, the best candidates, i.e. ZnO nano and micro particles, were tested on osteosarcoma and glioblastoma cell lines to demonstrate their potential for cancer treatment.

Convolutional Neural Network-Assisted Photoresist Formulation Discriminator Design of a Contact Layer for Electron Beam Lithography.

The photoresist formulation is closely related to the material properties, and its composition content determines the lithography imaging quality. To satisfy the process requirements, imaging verification of extensive formulations is required through lithography experiments. Identifying photoresist formulations with a high imaging performance has become a challenge. Herein, we develop a formulation discriminator of a metal oxide nanoparticle photoresist for a contact layer applied to electron beam lithography. This discriminator consists of convolutional neural network photoresist imaging and formulation classification models. A photoresist imaging model is adopted to predict the contact width of variable formulations, while a formulation classification model is used to classify formulations according to relative local critical dimension uniformity (RLCDU). The verification results indicate that the discriminator can accurately recognize photoresist formulations that simultaneously meet the conditions of contact width and RLCDU, and its feasibility has been demonstrated, providing a valuable reference for the preparation of photoresist materials.

Structural, optical, antibacterial, antifungal, and anticancer activity of sodium alginate-pluronic-F127-tin dioxide nanoparticles prepared via microwave-assisted green process

The green synthesis of inorganic metal oxide nanoparticles is essential because it reduces environmental impact and enhances biocompatibility by using eco-friendly materials and processes. This sustainable approach also minimizes hazardous chemicals, promoting safer and cleaner production methods. The sodium alginate-Pluronic F127-modified SnO2 (SAPFSO) NPs were prepared using the green method using Psidium guajava leaf extract. The SAPFSO NPs exhibit a tetragonal rutile structure from the X-ray diffraction patterns. The FESEM and EDAX spectra identified the morphology and chemical composition. The Sodium Alginate, Pluronic-F127, and SnO2 functional group vibrations can be seen in the FTIR spectra. The DLS spectra and hydrodynamic sizes of SAPFSO NPs were observed at 183 nm. The various surface defects of SAPFSO NPs were identified from the PL spectrum. The antimicrobial activity of SAPFSO NPs was tested against gram-positive and gram-negative strains such as S. aureus, K. pneumoniae, S. dysenteriae, S. pneumoniae, Bacillus megaterium, Proteus valgaris, and Candida albicans fungal strain using the well-diffusion method. To increase the concentration, SAPFSO NPs also increased the antimicrobial activity. The anticancer activity of SAPFSO NPs tested against the human breast cancer cell line (MDA-MB-237). SAPFSO NPs exhibits potential anticancer activity against triple negative breast cancer cell line. These results support that SAPFSO NPs can be applied in healthcare and industrial settings to improve human health.

Emerging Nanomaterials as Versatile Nanozymes: A New Dimension in Biomedical Research.

The enzyme-mimicking nature of versatile nanomaterials proposes a new class of materials categorized as nano-enzymes, ornanozymes. They are artificial enzymes fabricated by functionalizing nanomaterials to generate active sites that can mimic enzyme-like functions. Materials extend from metals and oxides to inorganic nanoparticles possessing intrinsic enzyme-like properties. High cost, low stability, difficulty in separation, reusability, and storage issues of natural enzymes can be well addressed by nanozymes. Since 2007, more than 100 nanozymes have been reported that mimic enzymes like peroxidase, oxidase, catalase, protease, nuclease, hydrolase, superoxide dismutase, etc. In addition, several nanozymes can also exhibit multi-enzyme properties. Vast applications have been reported by exploiting the chemical, optical, and physiochemical properties offered by nanozymes. This review focuses on the reported nanozymes fabricated from a variety of materials along with their enzyme-mimicking activity involving tuning of materials such as metal nanoparticles (NPs), metal-oxide NPs, metal-organic framework (MOF), covalent organic framework (COF), and carbon-based NPs. Furthermore, diverse applications of nanozymes in biomedical research are discussed in detail.

Synthesis of cobalt- ferrite and zinc oxide metal nanoparticles based-bentonite using SDS and their investigation as catalysts in synthesis of benzylbarbiturocoumarins.

In this research, a suitable and efficient CoFe2O4@ZnO@Bentonite nano-catalyst was designed and synthesized by using zinc oxide (ZnO) and cobalt ferrite (CoFe2O4) nanoparticles and bentonite by microwave irradiation. Characteristics of the synthesized nanocomposite were investigated by Fourier transform infrared (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray (EDX), transmission electron microscope (TEM), X-ray diffraction (XRD), Bruner- Emmett-Teller (BET) and vibrating sample magnetometer (VSM) techniques. The produced catalyst was effectively employed as a supported solid acid catalyst in mildly agitated three-component reactions involving aromatic aldehydes, 4-hydroxycoumarin, and 1,3-dimethyl-barbituric acid in a single pot to produce benzylbarbiturocoumarins. Starting materials were condensed via three C-C bond formation by CoFe2O4@ZnO@Bentonite as an efficient, recyclable, and environmentally safe nanocatalyst to obtain target products. The advantages of this method include using a natural substrate, small amounts of catalyst, aqueous media, performing reactions at ambient temperature, simple separation and purification of products, and good yields with short reaction times.

(Invited) Plasmon-Driven Nitrogen Photofixation

Ammonia is one of the most important chemicals as well as an efficient energy carrier. The nitrogen element is indispensable for nearly all living species on the earth. However, dinitrogen molecules that are abundant in the atmosphere cannot be used directly by living species. They need to be converted into ammonia or nitrate for use. Such conversion is known as nitrogen fixation. Because natural nitrogen fixation is insufficient for sustaining all population on the earth, the industrial Haber-Bosch process has been developed for producing ammonia from dinitrogen and dihydrogen. The process consumes a large amount of energy and generates a large amount of carbon dioxide. Photocatalytic nitrogen fixation can operate under mild conditions and uses solar energy and water. It offers an intriguing alternative approach for the conversion of atmospheric dinitrogen into ammonia.Plasmonic metal nanocrystals can effectively absorb light and efficiently generate hot charge carriers. Compared to traditional interband excitation in semiconductors, plasmon excitation offers a new approach for generating hot charge carriers, which can thereafter be utilized for various physical and chemical processes. The use of plasmonic hot charge carriers for photocatalysis has become a hot research topic in the recent years. Plasmonic hot charge carriers can not only enhance the reaction yield and selectivity, but also introduce new reaction pathways. Moreover, the plasmon resonance wavelengths of various nanoparticles can be synthetically adjusted over a broad range that surpasses the solar spectrum.We have demonstrated the powerfulness of localized plasmon resonance on driving photocatalytic reduction of atmospheric nitrogen, where plasmonic hot electrons play an essential role. First, Au nanoparticles are anchored on ultrathin titania nanosheets with oxygen vacancies. The oxygen vacancies chemisorb and activate nitrogen molecules, which are subsequently reduced to ammonia by plasmonic hot electrons generated from the Au nanoparticles. Our synthesized all-inorganic hybrid structures mimic the function of biological nitrogenase enzymes, where the plasmonic Au nanoparticles play the role of the Fe proteins and the titania nanosheets play the role of the MoFe proteins. Second, we have extended the biomimetic idea into another popular semiconductor. A plasmonic hybrid catalyst is produced by uniformly embedding Au nanoparticles in the mesopores of nitrogen-deficient hollow carbon nitride spheres. The carbon nitride spheres possess abundant nitrogen vacancies, which serve as the sites for nitrogen chemisorption and activation, and capture photoexcited electrons stemmed from the carbon nitride spheres and the plasmon resonance of the embedded Au nanoparticles for the efficient reduction of the adsorbed nitrogen molecules to ammonia. Third, when metal-semiconductor hybrid nanostructures are designed as photocatalysts for nitrogen fixation, the introduction of a Schottky barrier at the junction is unavoidable. This Schottky barrier will undoubtedly lower the utilization efficiency of plasmonic charge carriers because only plasmonic hot charge carriers with sufficient energies and appropriate momenta can overcome the barrier and inject into the semiconductor. In addition, noble metals are well-known to be expensive. We have synthesized different metal oxide nanoparticles that are degenerately doped and thus exhibit strong plasmon resonance and demonstrated Schottky-barrier-free plasmonic photocatalysts for nitrogen fixation. The excitation of the plasmon resonance in these metal oxide nanoparticles can efficiently generate hot charge carriers. Because of the abundance of defects in these degenerately doped semiconductor nanoparticles, the photogenerated hot charge carriers can rapidly migrate to the defect sites and get trapped there. In this way, the lifetime of the plasmonic hot charge carriers is Moreover, these metal oxide nanoparticles possess active sites for adsorbing and activating dinitrogen molecules. Therefore, they function in a “one-stone-two-birds” manner. As a result, a record-high solar-to-chemical energy conversion efficiency has been achieved.