Synthesis of sulfated β‐cyclodextrin/cotton/ZnO nano composite for improve the antibacterial activity and dyeability with Azadirachta indica

The sulfated β‐cyclodextrin (sb‐cd) was prepared from β‐cyclodextrin and the sb‐cd was crosslinked with cotton fabric using ethylenediaminetetraacetic acid (EDTA) as crosslinker. After crosslinking, the synthesized ZnO nanoparticles were padded on this fabric surface. Then, the treated fabrics were dyed with neem extract. The synthesized polymer, crosslinked and nanoparticle‐treated cotton fabrics were characterized using fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), particle sized analyzer, and transmission electron microscopy (TEM) studies. The antibacterial test was done against Staphylococcus aureus and Escherichia coli bacterium. The composite coated with neem dyed cotton fabric has exhibited 71% of dye uptake with 2–3 fastness grade and it has 99% of antibacterial efficiency for S. aureus and 97% for E. coli bacterium. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Mesoporous Ag/ZnO hybrid cages derived from ZIF-8 for enhanced photocatalytic and antibacterial activities

Ag/ZnO hybrid cages with well-preserved polyhedron shape and rich mesoporous structures were prepared thorough in situ pyrolysis of AgNO₃ impregnated ZIF-8 precursor. Due to the bi-template function of ZIF-8, the as-prepared cages show well-defined hollow chamber inherited from the precursor and uniformly embedded Ag nanoparticles (NPs). The as-introduced Ag NPs could enhance the light absorption and promote charge separation, which finally improve the antibacterial performances. Therefore, compared with pure ZnO, the Ag/ZnO hybrid cages demonstrate prominent photocatalytic degradation of different organic dyes, such as Methylene Blue, Methylene Orange, Eosin and Rhodamine B under simulated sunlight. In addition, the hybrid Ag/ZnO cages exhibit outstanding inhibition performances against Escherichia coli, Staphylococcus aureus, and the highly infective Mycobacterium-tuberculosis. The photocatalytic and antibacterial mechanism of the hybrid Ag/ZnO cages were also studied in detail by means of optical/electrochemical dynamic tests and Ag⁺ and Zn²⁺ release measurements.     

In vitro bactericidal effect of ultrasonically sol–gel-coated novel CuO/TiO<Subscript>2</Subscript>/PEG/cotton nanocomposite for wound care

Protection against bacterial contamination remains a demand for healthcare textiles such as wound dressings to reduce or eliminate hospital-acquired infections related to antibiotic-resistant bacteria. We report herein a simple and straightforward in situ approach to deposit copper oxide and titanium oxide nanoparticles onto cotton fabric using a sonochemical-mediated sol–gel method. Modification of the cotton surface was achieved by incorporation of citric acid (CA) and polyethylene glycol (PEG) to improve the attachment of the nanoparticles and reduce the attachment of bacteria to the cotton surface, respectively. The resultant cotton fabric was used against Escherichia coli as a Gram-negative bacterium and Staphylococcus aureus as a Gram-positive bacterium in dark condition as an in vitro model for treatment of bacterial wound infection. The effects of different treatment parameters including duration and frequency of ultrasonic irradiation, surface modification with PEG and/or CA, and cotton chemical composition with different metal oxide molar ratios on the antibacterial activity of the treated cotton fabric were studied. All treated cotton fabrics showed antibacterial activity, with higher efficiency for those coated with CuO or CuO/TiO₂ (1:1 molar ratio) among the single metal oxide and composite-modified cotton fibers, respectively. Our results show that such functionalized cotton fibers could actively fight the spread of bacterial infections by preventing bacterial adhesion, enabling more efficient bonding, and ultrasonically promoting generation of nanoparticles and their strong adhesion to the fabric surface.     

Synthesis of dynamic g-C3N4/Fe@ZnO nanocomposites for environmental remediation applications

An effective g-C₃N₄/Fe@ZnO heterostructured photocatalyst was synthesized by a simple chemical co-precipitation method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and ultraviolet–visible spectroscopy. Transmission electron microscopy revealed that 7-8 nm-sized 1%Fe@ZnO nanoparticles were evenly distributed on g-C₃N₄ nanosheets to form a hybrid composite. The photocatalytic effectiveness of the composites was assessed against methylene blue dye, and it was found that the 50%g-C₃N₄/Fe@ZnO photocatalyst was more efficient in harvesting solar energy to degrade dye than the ZnO, 1%Fe@ZnO, g-C₃N₄, g-C₃N₄/ZnO and (10, 25, 40, 60 & 75 wt%) g-C₃N₄/Fe@ZnO samples. The antibacterial competency of the samples was also explored against Gram-positive (Bacillus subtilis, Staphylococcus aureus and Streptococcus salivarius) and Gram-negative (Escherichia coli) bacteria through the well diffusion method. The 50%g-C₃N₄/Fe@ZnO nanocomposite exhibited a superior antibacterial action compared to that of the rest of the samples. The exceptionally improved photocatalytic and antimicrobial efficiency of the 50%g-C₃N₄/Fe@ZnO composite was primarily accredited to the synergic outcome of the interface established between Fe@ZnO nanoparticles and g-C₃N₄ nanosheets.     

Synthesis of antibacterial N-halamine acryl acid copolymers and their application onto cotton

A series of N-halamine copolymers are synthesized by reacting hydantoinylacrylamide (HA) with acrylic acid (AA) in several mole ratios. The synthesized copolymers are characterized by Fourier transform infrared (FTIR) and ¹H NMR and coated onto cotton fabrics. The coated cotton fabrics are rendered antibacterial by chlorinating with dilute household bleach solution. The ultraviolet (UVA) light stabilities of the resulting copolymers on the coated cotton fabrics are investigated; the results show that UVA exposure has minimal effect on the structure of the copolymers but can cause partial loss of the chlorine loading on the coated cotton fabrics. The coated cotton fabrics exhibit excellent antibacterial efficacies achieving inactivations of about six logs of Staphylococcus aureus and Escherichia coli O157:H7 within 1 min of contact time. The cotton fabrics coated with the copolymers would best be employed in disposable fabric applications because of lack of washing fastness due to the weak bonding interaction between the AA unit and cellulose. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47426.     

Development of polyaniline/zinc oxide nanocomposite impregnated fabric as an electrostatic charge dissipative material

The paper presents the electrostatic charge dissipative performance of conducting polymer nanocomposite impregnated fabric based on polyaniline (PANI) and zinc oxide nanoparticles (ZnO NPs). Conducting polymer nanocomposites (PANI‐ZnO NPs) were synthesized by in situ chemical oxidative polymerization of aniline by using sodium dodecyl sulfate as surfactant and HCl as dopant. Coating of PANI‐ZnO nanocomposites on the cotton fabric was carried out during polymerization. The interaction of ZnO NPs with the PANI matrix was determined by Fourier transform infrared spectra (FTIR), TGA, XRD, scanning electron Microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and conductivity measurements. The conductivity of PANI‐ZnO NP coated fabric was found to be in the range 10^?3 ? 10^?6 S cm^?1 depending on the loading concentration of ZnO NPs in the polymer matrix. TEM and HRTEM images showed that the PANI‐ZnO nanocomposites had an average diameter of 25–30 nm and were nicely dispersed in the polymer matrix. Antistatic performance of the nanocomposite impregnated fabric was investigated by static decay meter and John Chubb instrument. The static decay time of the film was in the range 0.5 ? 3.4 s on recording the decay time from 5000 V to 500 V. This indicated that the nanocomposite based on PANI‐ZnO nanocomposites has great potential to be used as an effective antistatic material. © 2015 Society of Chemical Industry     

Synthesis and photocatalytic activity of g-C3N4/ZnO composite microspheres under visible light exposure

In this paper, a novel g-C₃N₄/ZnO composite microspheres (CZCM) with enhanced photocatalytic activity under visible light exposure were successfully prepared by a self-assembly method followed by calcination in the air. A hierarchical structure in which ZnO microspheres were closely covered with g-C₃N₄ nanosheets was constructed. The microstructure and photocatalytic activities of the CZCM were characterized. The photocatalytic property of CZCM was evaluated by degrading solution Methyl Orange (MO) and Tetracycline (TC). The effects of varied contents of g-C₃N₄ on the photocatalytic capability of CZCM were systematically investigated and the results show that the optimized CZ-15% sample exhibit much higher photocatalytic degradation efficiency than that of bare g-C₃N₄ or ZnO under identical conditions. The analysis of Photoluminescence (PL) and photocurrent (PC) independently conformed that the photo-induced electron-hole (e^?-h⁺) pairs in the CZCM were effectively generated and responsible for the observed photocatalysis. The enhanced adsorption of visible-light and the effective charge separation on the surface of CZCM enabled significant improvement of photocatalytic performance. According to the experimental results and relative energy band levels of the two semiconductors, a possible photocatalysis mechanism for the reaction process is proposed.     

纳米氧化锌和纳米银对棉织物的多功能整理

以植物金银花提取物作为还原剂制备了纳米ZnO和纳米Ag,通过浸轧法将纳米ZnO单独整理以及将两者依次整理到棉织物上制备多功能棉织物(ZnO-棉织物、ZnO/Ag-棉织物).利用SEM、XRD、FTIR分析了整理前后棉织物的形貌和结构,并探讨了整理后棉织物的多功能性.结果表明,棉织物上的纳米粒子分布较均匀且发生了轻微团聚.与ZnO-棉织物相比,ZnO/Ag-棉织物对亚甲基蓝(MB)和红酒的降解率分别提高了7.09％和10.61％,说明纳米Ag提升了纳米ZnO的光催化活性.ZnO-棉织物经过10次洗涤后其纳米粒子含量虽有小幅下降,但对MB的降解率仍达到83.24％以上,说明负载纳米粒子后棉织物具有良好的自清洁能力和耐洗性能.此外,ZnO-棉织物和ZnO/Ag-棉织物的紫外防护系数(UPF)值分别达到33.23和41.06,对大肠杆菌和金黄色葡萄球菌的抑菌率均达到95％以上,表现出优良的抗紫外线性和抗菌性能.     

Functionalization of cotton fabric with nanosized TiO<Subscript>2</Subscript> coating for self-cleaning and antibacterial property enhancement

In this study, titanium dioxide (TiO₂) was used as coating compound to add self-cleaning and antibacterial functionality properties to the cotton fabric. TiO₂-consisting coating compounds were prepared at four different processing temperatures (20, 40, 60, and 80°C) in order to examine the influence of process temperature on average particle size. Among the prepared solutions, the one prepared at 80°C process temperature was selected for the dip coating application of the 100% cotton fabric, which formed a transparent nanosized TiO₂ film on the fibrous structure of fabric. Dip coating trials were done at five coating temperatures of 20, 40, 60, 80, and 100°C. TiO₂-coated and uncoated fabric samples were then tested to evaluate their self-cleaning and antibacterial activities. A self-cleaning activity test was conducted using uncoated and TiO₂-coated fabric samples which were stained with hot tea solution via dipping method. Stained fabric samples were illuminated under a solar simulator for the color changes to measure photocatalytic degradation of stain colors. Antibacterial performance of TiO₂-coated and uncoated fabric samples was determined against pure cultures of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213.     

Preparation of 3D crimped ZnO/PAN hybrid nanofiber mats with photocatalytic activity and antibacterial properties by blow-spinning

Zinc oxide (ZnO) nanostructures have received widespread attention due to their unique structure and broad application possibilities, but high preparation costs and agglomeration limit their usage. In this article, low-cost and environmentally friendly cellulose and ZnCl₂ are used to synthesize ZnO nanoparticles (ZnO NPs). Subsequently, multifunctional ZnO/polyacrylonitrile hybrid nanofiber mats (ZnO/PAN@NFMs) with mechanical stability suitable for large-scale application are prepared via solution blow-spinning. The synthesized ZnO/PAN@NFMs exhibit higher photodegradation of organic dyes than earlier reported semiconductors and good recycling performance with an organic dye degradation above 94%–98% after five cycles, which is ascribed to fixation of the ZnO NPs in the nanofibers. In addition, the inhibition rate for Escherichia coli and Staphylococcus aureus is above 99.9% and the bacteriostatic rate against E. coli remains as high as 99% after 10 cycles. From these properties, the synthesized composite ZnO/PAN@NFMs are promising for wastewater cleaning and antibacterial fabrics.     

Enhanced Activity and Sustained Release of Protocatechuic Acid,a Natural Antibacterial Agent,from Hybrid Nanoformulations with Zinc Oxide Nanoparticles

Hybrid nanostructures can be developed with inorganic nanoparticles (NPs) such as zinc oxide (ZnO) and natural antibacterials. ZnO NPs can also exert antibacterial effects, and we used them here to examine their dual action in combination with a natural antibacterial agent, protocatechuic acid (PCA). To produce hybrid nanoformulations, we functionalized ZnO NPs with four types of silane organic molecules and successfully linked them to PCA. Physicochemical assessment confirmed PCA content up to ~18% in hybrid nanoformulations, with a PCA entrapment efficiency of ~72%, indicating successful connection. We then investigated the in vitro release kinetics and antibacterial effects of the hybrid against Staphylococcus aureus. PCA release from hybrid nanoformulations varied with silane surface modification. Within 98 h, only 8% of the total encapsulated PCA was released, suggesting sustained long-term release. We used nanoformulation solutions collected at days 3, 5, and 7 by disc diffusion or log reduction to evaluate their antibacterial effect against S. aureus. The hybrid nanoformulation showed efficient antibacterial and bactericidal effects that also depended on the surface modification and at a lower minimum inhibition concentration compared with the separate components. A hybrid nanoformulation of the PCA prodrug and ZnO NPs offers effective sustained-release inhibition of S. aureus growth.     

Antibacterial and photocatalytic behaviour of green synthesis of Zn0.95Ag0.05O nanoparticles using herbal medicine extract

The present work aimed to synthesize Zn_0.95Ag_0.05O (ZnAgO) nanoparticles using rosemary leaf extracts as a green chemistry method. The characterization of Ag-doped ZnO nanoparticles was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet–visible spectrophotometry (UV–visible). The XRD, FTIR, and UV–visible spectra confirmed the formation of the presence of hexagonal ZnAgO nanoparticles. FESEM micrograph shows that the nanoparticles have been distributed homogeneously and uniformly. The morphology of ZnAgO nanoparticles is quasi-spherical configuration. Also, the mean particle size is in the range of 22–40 nm. The photocatalytic degradation of methylene blue in the presence of Ag-doped ZnO nanoparticles is nearly 98.5% after exposing 100 min. The ultraviolet lamp was used as the light source for photocatalyst degradation. The disc diffusion method was chosen to study the antibacterial activity of as-synthesized ZnAgO nanoparticles. Antibacterial activity of Zn_0.95Ag_0.05O nanoparticles against Staphylococcus aureus and Escherichia coli revealed that the as-synthesized ZnAgO nanoparticles were efficient in inhibition of bacterial growth.     

Construction of Er-doped ZnO/SiO2 composites with enhanced antimicrobial properties and analysis of antibacterial mechanism

Herein, silica carrier was used as underlying structure to prepare composite material loaded with rare earth element Er and Zn. Rare earth elements can improve antimicrobial effects of ZnO due to their specific electronic structure. Er–ZnO/SiO₂ hybrid antibacterial material was prepared through sol-gel method and its structure and morphology were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma emission spectroscopy and Brunauer-Emmett-Teller measurements. E. coli and S. aureus were selected as model bacteria to assess antibacterial activity of prepared hybrid material by plate coating method. Er–ZnO/SiO₂ exhibited good antibacterial activity towards E. coli and S. aureus. Increase in Er³⁺ concentration from 0.12% to 1.10% led to increase in antibacterial performance followed by subsequent decrease. Improving effect of Er relied on the molar ratio of Er doped in ZnO/SiO₂ hybrid material. The optimal sample was found to be 0.60%Er–ZnO/SiO₂, with antibacterial rates of 93.71% and 70.46% against E. coli and S. aureus, respectively. Antibacterial mechanism was assessed by fluorescence detection of reactive oxygen species. In addition, flame atomic absorption spectrometry was used to measure the amount of released Zn²⁺. Results also showed that 0.60%Er–ZnO/SiO₂ hybrid material generated more reactive oxygen species, released more Zn²⁺ ions, and had the largest surface area, which improved its antibacterial rate. Thus, Er enhanced antibacterial properties of ZnO/SiO₂, providing these composite materials with great potential as antibacterial products.     

Preparation and antibacterial properties of titanium-doped ZnO from different zinc salts

To research the relationship of micro-structures and antibacterial properties of the titanium-doped ZnO powders and probe their antibacterial mechanism, titanium-doped ZnO powders with different shapes and sizes were prepared from different zinc salts by alcohothermal method. The ZnO powders were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), and the antibacterial activities of titanium-doped ZnO powders on Escherichia coli and Staphylococcus aureus were evaluated. Furthermore, the tested strains were characterized by SEM, and the electrical conductance variation trend of the bacterial suspension was characterized. The results indicate that the morphologies of the powders are different due to preparation from different zinc salts. The XRD results manifest that the samples synthesized from zinc acetate, zinc nitrate, and zinc chloride are zincite ZnO, and the sample synthesized from zinc sulfate is the mixture of ZnO, ZnTiO₃, and ZnSO₄ · 3Zn (OH)₂ crystal. UV-vis spectra show that the absorption edges of the titanium-doped ZnO powders are red shifted to more than 400 nm which are prepared from zinc acetate, zinc nitrate, and zinc chloride. The antibacterial activity of titanium-doped ZnO powders synthesized from zinc chloride is optimal, and its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) are lower than 0.25 g L⁻¹. Likewise, when the bacteria are treated by ZnO powders synthesized from zinc chloride, the bacterial cells are damaged most seriously, and the electrical conductance increment of bacterial suspension is slightly high. It can be inferred that the antibacterial properties of the titanium-doped ZnO powders are relevant to the microstructure, particle size, and the crystal. The powders can damage the cell walls; thus, the electrolyte is leaked from cells.     

Preparation of heterostructure g-C3N4/ZnO nanorods for high photocatalytic activity on different pollutants (MB,RhB, Cr(VI) and eosin)

The g-C₃N₄/ZnO nanorods were prepared by simple hydrothermal, grinding and calcination methods. The characterization of g-C₃N₄/ZnO nanorods was done by different analytical techniques such as SEM, TEM, XRD, XPS, FT-IR and UV–Vis. g-C₃N₄/ZnO nanorods with heterostructures have been successfully synthesized without changing the structure between the monomers, which broadens the visible light response range and improves several major pollutants in water degradation rate. Photocatalytic studies were done for the degradation of MB, RhB, Cr(VI) and eosin which are almost fully degraded. The experimental results show that the photocatalytic performance of the nanorods is much better than others. The g-C₃N₄/ZnO photocatalyst has excellent stability and repeated cycle performance. Basing on the results of comprehensive free radical trapping test and ESR tests, it is proposed that the main active substance of the catalyst for degrading dyes is ·0₂^-, and ·OH played significant roles in the degradation process. A good photocatalytic mechanism has been proven.     

Phytofabrication,Characterization and Antibacterial Activity of <Emphasis Type="Italic">Cassia auriculata</Emphasis> Leaf Extract Derived CuO Nanoparticles

A simple, eco-friendly phytosynthesis of copper oxide nanoparticles (CuO NPs) using Cassia auriculata leaf extract was reported. The prepared CuO NPs was characterized by UV–vis spectroscopy which exhibited the surface plasmon resonance (SPR) band at 380–385 nm. TEM and EDX analysis confirmed that CuO NPs were spherical and in size range of 30–35 nm with identified elements Cu and O. X-ray diffraction (XRD) spectrum showed the crystalline nature of the prepared CuO NPs. FTIR spectrum confirmed the presence of Cu–O functional groups. CuO NPs showed significant antibacterial efficacy against all the tested bacterial strains, i.e., Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. CuO NPs showed strong antibacterial action against B. subtilis and E. coli than P. aeruginosa and S. aureus. The results of this study revealed that C. auriculata leaf extract was found to be an effective bio-reducing agent for CuO NPs synthesis and also the antibacterial efficacy of phytofabricated CuO may be useful for its applications in medical and textile industries.     

Development of mesoporous Bi2WO6/g-C3N4 heterojunctions via soft- and hard-template-assisted procedures for accelerated and reinforced photocatalytic reduction of mercuric cations under vis light irradiation

In this study, mesoporous Bi₂WO₆/g-C₃N₄ heterojunctions were developed using soft and hard templates [triblock copolymer surfactant (F127) and mesoporous silica (MCM-41), respectively]. The performance of the developed heterojunctions was assessed through the photocatalytic reduction of mercuric cations under Vis light illumination, with HCOOH being adopted to provide sacrificial holes agent. Surface measurements demonstrated that the fabricated specimens acquired large specific surface areas when compared with the neat ingredient. Furthermore, a transmission electron microscopy (TEM) analysis of the developed heterojunctions showed the homogeneous distribution of the spherical Bi₂WO₆ nanoparticles (NPs) on the surface of g-C₃N₄ nanosheets. Meanwhile, an accelerated rate (700 μ·mol·g^?1·h^?1) of photocatalytic mercuric cation reduction with improved efficiency (approximately 100%), compared with those of the pure ingredients [rate of 55 μ·mol·g^?1·h^?1 and efficiency of 13% for g-C₃N₄ nanosheets; rate of 95 μ·mol·g^?1·h^?1 and efficiency of 20% for mesoporous Bi₂WO₆ NPs], was accomplished via testing of the Bi₂WO₆/g-C₃N₄ heterojunction comprising 4 wt% Bi₂WO₆ after 40 min of illumination. Evidently, the efficiency of the photocatalytic reduction of mercuric cations endorsing the Bi₂WO₆/g-C₃N₄ heterojunction comprising 4 wt% Bi₂WO₆ NPs is 7.7 and 5 times more when compared with those of the neat g-C₃N₄ nanosheets and mesoporous Bi₂WO₆ NPs, respectively. The improved performance of the fabricated heterojunctions in the photocatalytic reduction of mercuric cations could be ascribed to i) fast diffusion of the mercuric cations through the mesoporous texture to the active ensembles, ii) greater specific surface area, iii) limited bandgap magnitude, iv) homogenous dispersion of the Bi₂WO₆ NPs on the surface of the nanosheets, and v) finite particle dimension of the mesoporous Bi₂WO₆ NPs. The durability and stability of the Bi₂WO₆/g-C₃N₄ heterojunctions were confirmed via their recyclability, which was maintained for up to five runs without pronounced activity loss.     

Evaluation of physicochemical and biological properties of SnO2 and Fe doped SnO2 nanoparticles

In recent decades, nanoparticle synthesis has been used for various physical and chemical methods. However, different toxic chemicals are used during this synthesis process to address these concerns, which has multiple effects on environmental toxicity and high cost. To avoid these problems, we need a cost-effective and environmentally friendly approach. In this study, green synthesis was used to make tin oxide (SnO₂) and ferrous doped tin oxide (SFO) nanoparticles (NPs) from Morinda citrifolia leaf extracts. The X-ray diffraction patterns of SnO₂ and SFO NPs reveal a tetragonal crystalline structure. From the FESEM image of synthesized SnO₂ and SFO NPs, their spherical structure and chemical composition were identified by EDX spectrum. Through the DLS spectrum, the hydrodynamic size was observed at 66 and 61 nm for SnO₂ and SFO NPs, respectively. In the FTIR spectrum, the O–Sn–O stretching vibration peak arises at (606 & 509 cm^?1 for SnO₂ NPs) and (613 & 538 cm^?1 for SFO NPs). Photoluminescence is used in materials to detect surface defects and impurity levels. The antibacterial activity of the SnO₂, SFO NPs, and conventional antibiotics like amoxicillin NPs is effectively inhibited against S. aureus and E. coli bacterial strains. SFO NPs exhibit a higher antibacterial activity as compared to SnO₂ and amoxicillin. The anticancer efficacy of increased SFO NPs compared to SnO₂ NPs was tested against (MDA-MB-237) human breast cancer cells. These results suggest that Fe ions modified SnO2 NPs could be used in healthcare industrial applications to improve human health.     

Evaluation of the biocompatibility and growth inhibition of bacterial biofilms by ZnO,Fe3O4 and ZnO@Fe3O4 photocatalytic magnetic materials

Magnetic nanostructured materials have found numerous biomedical applications. However, the influence of a magnetic field on the inhibition of pathogenic microorganisms has been poorly explored. Zinc and Iron nano-structured oxides have been widely used due to their biocompatibility and their excellent optoelectronic and magnetic properties. Nevertheless, little effort has been devoted to demonstrate their antibacterial activity at doses that are not harmful to mammalians. In this work, ZnO, Fe₃O₄ (MNPs) and ZnO@Fe₃O₄ (NCs) were synthesized and fully characterized. The materials exhibit good antibacterial activity to inhibit the growth of Staphylococcus aureus (S. aureus) and Helicobacter pylori (H. pylori) both, as planktonic cells and as biofilms structures at low doses. The photocatalytic activity of the materials (NCs) was demonstrated when radiated suspensions of NCs and microorganisms (MOs) exhibited higher inhibition growth of MOs in comparison to non-radiated assays. The materials show better antibacterial activity for biofilm growth inhibition in comparison to commercially available antibiotics. Magnetic antimicrobial films were fabricated by in situ deposition of MNPs in Arabic gum (AG) solution. The films exert enhanced antibacterial activity against S. aureus growth due to Fe³⁺lixiviation and magnetic disruption. Regarding the biocompatibility of the materials, ZnO modifies significantly biochemical parameters in Wistar rats after acute administration. Our results show that the composite ZnO@Fe₃O₄ at low doses: (a) exerts an optimum inhibition on the biofilm formation of microorganisms due to its synergetic activity of lixiviation of ions and oxidative activity; (b) good biocompatibility of the composite with living cells. These properties suit ZnO@Fe₃O₄ as potential candidates for the development of new anti-biofilm formulation.     

Silver-zinc oxide nanocomposite: From synthesis to antimicrobial and anticancer properties

A green method by Verbascum speciosum was used to synthesize zinc oxide nanoparticles (ZnO NPs). ZnO NPs were coated with silver to synthesize Ag–ZnO nanocomposite (NCs). The physicochemical properties of Ag–ZnO NCs were analyzed by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential. The FTIR indicated the peak of Zn–O vibration and some hydroxyl and carboxyl groups. PXRD analyses confirmed the synthesis of ZnO NPs and Ag–ZnO NCs. Due to the size of the crystallite obtained from PXRD, solid-phase sizes (from FESEM and TEM images), and dynamic sizes from DLS, agglomeration was observed. The Ag–ZnO NCs showed a negative charge surface (?49.3 mV). Ag–ZnO NCs had a high antibacterial activity towards two most important infectious bacteria (i.e., Escherichia coli and Staphylococcus aureus) and anticancer activity against human liver-carcinoma cells (HepG2). Later, it depended on time and concentration of Ag–ZnO NCs. The cytotoxicity properties of Ag–ZnO NCs were also studied against NIH-3T3 as a normal cell, where the results verified the lower cell toxicities of nanocomposite than the HepG2.