Phytoassisted synthesis of CuO and Ag-CuO nanocomposite, characterization, chemical sensing of ammonia, degradation of methylene blue.

The elimination of hazardous industrial pollutants from aqueous solutions is an emerging area of scientific research and a worldwide problem. An efficient catalyst, Ag-CuO was synthesized for the degradation of methylene blue, the chemical sensing of ammonia. A simple novel synthetic method was reported in which new plant material Capparis decidua was used for the reduction and stabilization of the synthesized nanocatalyst. A Varying amount of Ag was doped into CuO to optimize the best catalyst that met the required objectives. Through this, the Ag-CuO nanocomposite was characterized by XRD, SEM, HR-TEM, EDX, and FTIR techniques. The mechanism of increased catalytic activity with Ag doping involves the formation of charge sink and suppression of drop back probability of charge from conduction to valance band. Herein, 2.7 mol % Ag-CuO exhibited better catalytic activities and it was used through subsequent catalytic experiments. The experimental conditions such as pH, catalyst dose, analyte initial concentration, and contact time were optimized. The as-synthesized nanocomposite demonstrates an excellent degradation efficacy of MB which is 97% at pH 9. More interestingly, the as-synthesized catalyst was successfully applied for the chemical sensing of ammonia even at very low concentrations. The lower limit of detection (LLOD) also called analytic sensitivity was calculated for ammonia sensing and found to be 1.37 ppm.

Removal of organic pollutants through hydroxyl radical-based advanced oxidation processes.

The use of Advance Oxidation Process (AOPs) has been extensively examined in order to eradicate organic pollutants. This review assesses the efficacy of photolysis, O3 based (O3/UV, O3/H2O2, O3/H2O2/UV, H2O2/UV, Fenton, Fenton-like, hetero-system) and sonochemical and electro-oxidative AOPs in this regard. The main purpose of this review and some suggestions for the advancement of AOPs is to facilitate the elimination of toxic organic pollutants. Initially proposed for the purification of drinking water in 1980, AOPs have since been employed for various wastewater treatments. AOPs technologies are essentially a process intensification through the use of hybrid methods for wastewater treatment, which generate large amounts of hydroxyl (•OH) and sulfate (SO4·-) radicals, the ultimate oxidants for the remediation of organic pollutants. This review covers the use of AOPs and ozone or UV treatment in combination to create a powerful method of wastewater treatment. This novel approach has been demonstrated to be highly effective, with the acceleration of the oxidation process through Fenton reaction and photocatalytic oxidation technologies. It is clear that Advance Oxidation Process are a helpful for the degradation of organic toxic compounds. Additionally, other processes such as •OH and SO4·- radical-based oxidation may also arise during AOPs treatment and contribute to the reduction of target organic pollutants. This review summarizes the current development of AOPs treatment of wastewater organic pollutants.

The construction of novel CuO/SnO2@g-C3N4 photocatalyst for efficient degradation of ciprofloxacin, methylene blue and photoinhibition of bacteria through efficient production of reactive oxygen species.

Water pollution due to organic waste and various microorganisms cause severe health problems. Numbers of techniques are used to eliminate organic waste and microorganisms from water because water pollution is a substantial issue in the current era. In the present study, sustainable and effective CuO/SnO2@g-C3N4 nanocomposites were prepared via green and chemical approach. The photo degradation of ciprofloxacin (CIP) and methylene blue (MB) by the green synthesized nanocomposite were tested. Visible and dark conditions both were used to conduct this test. The results showed that the nanocomposite is much more effective in light than in dark conditions. The synthesized nanocomposite was also tested both in light and dark against highly drug resistant microorganisms' Bacillus subtilis (B.subtilis) and Escherichia coli (E.coli). As a result, the antibacterial evaluation revealed substantial antibacterial activity in the presence of light, with a zone of inhibition covering an area of 19 (±0.5) mm and 20 (±0.1) mm, respectively, against gram negative and gram positive bacteria such as E. coli and B. subtilis. The results showed that the CuO/SnO2@g-C3N4 nanocomposite is a stable, eco-friendly photocatalyst with significant resistance to CIP and MB degradation and a substantial inhibitory effect towards microorganisms in visible light.

Rapid photodegradation of toxic organic compounds and photo inhibition of bacteria in the presence of novel hydrothermally synthesized Ag/Mn-ZnO nanomaterial.

Purified water is the most concerning issue these days, and utmost conventional practices are allied with various downsides. Therefore, an ecologically benign and easily amicable therapeutic approach is the requirement. In this wonder, nanometer phenomena bring an innovative change to the material world. It has the potential to produce nanosized materials for wide-ranging applications. The subsequent research highlights the synthesis of Ag/Mn-ZnO nanomaterial via a one-pot hydrothermal route with an efficient photocatalytic activity against organic dyes and bacteria. The outcomes revealed that the size of the particle (4-5 nm) and dispersion of spherically shaped silver nanoparticles intensely affected by employing Mn-ZnO as a support material. Use of silver NPs as a dopant activates the active sites of the support medium and provides a higher surface area to upsurge the degradation rate. The synthesized nanomaterial was evaluated against photocatalytic activity using Methyl orange and alizarin red as model dyes and confided that more than 70% of both the dyes degraded under 100 min duration. It is well recognize that the modified nanomaterial recreates an essential role in every light-based reaction, and virtually produced highly reactive oxygen species. The synthesized nanomaterial was also evaluated against E. coli bacterium both in light and dark. The zone of inhibition in the presence of Ag/Mn-ZnO was observed both in light (18 ± 0.2 mm) and dark (12 ± 0.4 mm). The hemolytic activity shows that Ag/Mn-ZnO has very low toxicity. Hence, the prepared Ag/Mn-ZnO nanomaterial might be an effective tool against the depletion of further harmful environmental pollutants and microbes.

Brief review: Applications of nanocomposite in electrochemical sensor and drugs delivery.

The recent advancement of nanoparticles (NPs) holds significant potential for treating various ailments. NPs are employed as drug carriers for diseases like cancer because of their small size and increased stability. In addition, they have several desirable properties that make them ideal for treating bone cancer, including high stability, specificity, higher sensitivity, and efficacy. Furthermore, they might be taken into account to permit the precise drug release from the matrix. Drug delivery systems for cancer treatment have progressed to include nanocomposites, metallic NPs, dendrimers, and liposomes. Materials' mechanical strength, hardness, electrical and thermal conductivity, and electrochemical sensors are significantly improved using nanoparticles (NPs). New sensing devices, drug delivery systems, electrochemical sensors, and biosensors can all benefit considerably from the NPs' exceptional physical and chemical capabilities. Nanotechnology is discussed in this article from a variety of angles, including its recent applications in the medical sciences for the effective treatment of bone cancers and its potential as a promising option for treating other complex health anomalies via the use of anti-tumour therapy, radiotherapy, the delivery of proteins, antibiotics, and vaccines, and other methods. This also brings to light the role that model simulations can play in diagnosing and treating bone cancer, an area where Nanomedicine has recently been formulated. There has been a recent uptick in using nanotechnology to treat conditions affecting the skeleton. Consequently, it will pave the door for more effective utilization of cutting-edge technology, including electrochemical sensors and biosensors, and improved therapeutic outcomes.

An Eco-Benign Biomimetic Approach for the Synthesis of Ni/ZnO Nanocomposite: Photocatalytic and Antioxidant Activities.

With the increasing demand for wastewater treatment and multidrug resistance among pathogens, it was necessary to develop an efficient catalyst with enhanced photocatalytic and antibacterial applications. The present study proposes a facile and green strategy for synthesizing zinc oxide (ZnO) decorated nickel (Ni) nanomaterials. The synthesized Ni/ZnO nanocomposite displays a high crystallinity and spherical morphology, which was systematically characterized by XRD, SEM, FT-IR, UV-visible spectroscopy, EDX, HRTEM, and XPS techniques. In addition, the bacteriological tests indicated that Ni/ZnO nanocomposite exhibits potent antibacterial activity against human pathogens, i.e., Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The inhibition zone observed in light and dark conditions for E. coli was 16 (±0.3) mm and 8 (±0.4) mm, respectively, which confirms the high efficacy of the nanocomposite in the presence of light compared to dark conditions. The detailed inhibition mechanism of said bacterium and damage were also studied through fluorescence spectroscopy and SEM analysis, respectively. Evaluation of antioxidant activity based on free radical scavenging activity revealed that the Ni/ZnO nanocomposite effectively scavenges DPPH. In the photocatalytic performance, the Ni/ZnO nanocomposite exhibited a remarkable degradation ability under the optimized condition, which was attributed to their controllable size, high surface area, and exceptional morphology. Good selectivity, high photodegradation, and antibacterial activities and satisfactory hemolytic behavior of the as-prepared nanocomposite make them able to become a potential candidate for superior biological performance and environmental remediation.

Synthesis of MnSe-Based GO Composites as Effective Photocatalyst for Environmental Remediations.

In this work, a manganese selenide/graphene oxide (MnSe/GO)-based composite was prepared for wet-chemical assisted method against organic dye; herein, methylene blue (MB) dye removal from the water was employed as a metal selenide-based photocatalyst. The synthesized MnSe/GO composite was systematically characterized by X-ray diffraction (XRD), Fourier transform electron microscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and UV-visible diffuse reflectance spectroscopy (UV-vis. DRS). The structural characteristic revealed the adequate synthesis of the sample with good crystallinity and purity of the obtained products. The morphological analysis indicates the formation of MnSe nanoflakes composed of tiny particles on their surface. At the same time, the GO nanosheets with high aggregation were formed, which may be due to the van der Waals forces. The bond interaction and compositional analysis studies confirmed and supported the structural findings with high purity. The optical analysis showed the bandgap energies of MnSe and their composites MnSe (1.7 eV), 7% GO-MnSe (2.42 eV), 14% GO-MnSe (2.6 eV), 21% GO-MnSe (3.02 eV), and 28% GO-MnSe (3.24 eV) respectively, which increase the bandgap energy after GO and MnSe recombination. Among different contents, the optimized 21% GO-MnSe composite displayed enhanced photocatalytic properties. For instance, a short time of 90 min was taken compared with other concentrations due to the narrow bandgap of MnSe and the highly conductive charge carrier's support, making the process to remove MB from water faster. These results show that the selenide-based photocatalyst can be an attractive candidate for future advanced photocatalysis applications.

Development of Efficient and Recyclable ZnO-CuO/g-C3N4 Nanocomposite for Enhanced Adsorption of Arsenic from Wastewater.

Arsenic (III) is a toxic contaminant in water bodies, especially in drinking water reservoirs, and it is a great challenge to remove it from wastewater. For the successful extraction of arsenic (III), a nanocomposite material (ZnO-CuO/g-C3N4) has been synthesized by using the solution method. The large surface area and plenty of hydroxyl groups on the nanocomposite surface offer an ideal platform for the adsorption of arsenic (III) from water. Specifically, the reduction process involves a transformation from arsenic (III) to arsenic (V), which is favorable for the attachment to the -OH group. The modified surface and purity of the nanocomposite were characterized by SEM, EDX, XRD, FT-IR, HRTEM, and BET models. Furthermore, the impact of various aspects (temperatures, pH of the medium, the concentration of adsorbing materials) on adsorption capacity has been studied. The prepared sample displays the maximum adsorption capacity of arsenic (III) to be 98% at pH ~ 3 of the medium. Notably, the adsorption mechanism of arsenic species on the surface of ZnO-CuO/g-C3N4 nanocomposite at different pH values was explained by surface complexation and structural variations. Moreover, the recycling experiment and reusability of the adsorbent indicate that a synthesized nanocomposite has much better adsorption efficiency than other adsorbents. It is concluded that the ZnO-CuO/g-C3N4 nanocomposite can be a potential candidate for the enhanced removal of arsenic from water reservoirs.

Diversity in boardroom and debt financing: A case from China.

The study aims to explore the role of gender diversity in debt financing choices among Chinese listed firms. The study used the Chinese listed firm's data from 1991 to 2022 from the Chinese Stock Market return. The study used the fixed effect regression analysis and revealed that gender diversity positively affects debt financing among Chinese firms. Additionally, mass theory results suggested that at least three females on the board significantly influence firms. It served as the voice of gender diversity to influence the board's decisions regarding debt financing. The study has several theoretical and practical implications. This study will enlighten the Chinese boardroom dynamics by reassuring them to add more females to diversity policies. It will benefit future studies on boardroom activities and debt financing in emerging economies. It will be practical guidance for the Chinese policymakers, governing authorities, and corporate executives. The study stresses the need for significant diversity on the board rather than one female presence on the board. Secondly, this study contradicts the stereotype perception that females are not making risky decisions.

Effect of light-dark conditions on inhibition of Gram positive and gram negative bacteria and dye decomposition in the presence of photocatalyst Co/ZnO nanocomposite synthesized by ammonia evaporation method.

Environmental pollution and various bacterial strains cause severe health problems. Thus a need exists to synthesize new materials and develop new techniques which can be used against these hazardous pathogens and components. In this research work, sustainable and effective Co/ZnO nanocomposites were prepared via a new hydrothermal technique and ammonia evaporation method. The synthesized nanomaterial was analytically characterized through various techniques such as X-ray diffraction (XRD), UV-vis spectroscopy, Scanning electron microscope (SEM), High transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The as prepared nanocomposite was tested for photodegradation of methylene blue (MB). This test was performed both in visible light and in dark condition. The results demonstrate that the said material is more efficient in light compared to dark conditions and decomposed more than 80% MB dye only in 60 min. The synthesized nanomaterial Co/ZnO was also tested against highly drug resistant bacteria Escherichia coli and Staphylococcus aureus both in light and dark. Hence, the antibacterial assessment indicates the zone of inhibition in visible light of Co/ZnO counter with Escherichia coli is 15 (±0.2) and for Staphylococcus aureus is 18 (±0.4) mm and in dark for Escherichia coli is 11 (±0.6) and for Staphylococcus aureus is 14 (±0.1) mm. Moreover, the detail mechanism, reactive oxygen species production and bacterial surface damage were also observed. We demonstrate that Co/ZnO nanomaterial is stable, eco-friendly photocatalyst shows high strength against MB degradation and also shows strong inhibition effect against pathogens in visible light.

Optimization of Platinum Nanoparticles (PtNPs) Synthesis by Acid Phosphatase Mediated Eco-Benign Combined with Photocatalytic and Bioactivity Assessments.

Noble metal nanoparticles (NMNPs) are viable alternative green sources compared to the chemical available methods in several approach like Food, medical, biotechnology, and textile industries. The biological synthesis of platinum nanoparticles (PtNPs), as a strong photocatalytic agent, has proved as more effective and safer method. In this study, PtNPs were synthesized at four different temperatures (25 °C, 50 °C, 70 °C, and 100 °C). PtNPs synthesized at 100 °C were smaller and exhibited spherical morphology with a high degree of dispersion. A series of physicochemical characterizations were applied to investigate the synthesis, particle size, crystalline nature, and surface morphology of PtNPs. The biosynthesized PtNPs were tested for the photodegradation of methylene blue (MB) under visible light irradiations. The results showed that PtNPs exhibited remarkable photocatalytic activity by degrading 98% of MB only in 40 min. The acid phosphatase mediated PtNPs showed strong bacterial inhibition efficiency against S. aureus and E. coli. Furthermore, it showed high antioxidant activity (88%) against 1,1-diphenyl-2-picryl-hydrazil (DPPH). In conclusion, this study provided an overview of the applications of PtNPs in food chemistry, biotechnology, and textile industries for the deterioration of the natural and synthetic dyes and its potential application in the suppression of pathogenic microbes of the biological systems. Thus, it could be used as a novel approach in the food microbiology, biomedical and environmental applications.

Uncaria rhynchophylla mediated Ag/NiO nanocomposites: A new insight for the evaluation of cytotoxicity, antibacterial and photocatalytic applications.

The increase of microbial resistance poses threats to human health. Therefore, efficient treatment of microbial resistance is a global challenge.. During this study, the Ag/NiO nanocomposite was fabricated via simple and ecofriendly method, using Uncaria rhynchophylla extract as a reducing and capping agent to avoid the aggregation of as synthesized nanomaterials. Here, a range of characterization techniques were employed to characterize the sample which includes UV-vis spectroscopy, X-ray diffraction, FTIR spectroscopy, electron diffraction spectroscopy (EDX), scanning electron microscopy (SEM). Furthermore, the resultant nanocomposite demonstrated an efficient ability for the inhibition of both gram-positive and gram negative pathogenic multidrug resistant bacteria. Additionally, the Ag/NiO nanocomposite showed a durable antioxidant effect against DPPH that could still reach 63% at very low concentration, i.e. 0.5 mg/mL. Interestingly, the synthesized nanocomposite is efficient for the production of reactive oxygen species (ROS) and shows no hemolytic activity. Likewise, the Ag/NiO nanocomposite displayed excellent photocatalytic activity to degrade 85% methylene blue (MB) by 4 mg/25 mL and could be used for waste water treatment. It is believed that synthesized nanostructure with desirable morphology and preparation simplicity can be promising material for antimicrobial, antioxidant and catalytic applications.

Facile synthesis of silver modified zinc oxide nanocomposite: An efficient visible light active nanomaterial for bacterial inhibition and dye degradation.

The present study reports the synthesis of silver (Ag) decorated zinc oxide (ZnO) nanocomposite via green synthesis method by using Acacia arabica plant leaves extract as both reducing and capping agent. The results clearly indicate a uniform distribution of Ag nanoparticles (NPs) over ZnO surface. Various analytical and spectroscopic techniques were used for investigating the formation and morphology of as-synthesized Ag/ZnO nanocomposites. Emergence of SPR at 424 and 378 nm confirmed the synthesis of AgNPs and ZnO respectively. The confirmation of elemental composition and crystal structure of prepared nanomaterials (NMs) was carried out via EDX and XRD analysis. Results obtained from HRTEM and SEM analysis indicated small sized spherically shaped NMs. The as-synthesized was checked for its photocatalytic activity towards degradation of MB in the presence as well as absence of light irradiation. Results of degradation study revealed that Ag/ZnO exhibits remarkable photocatalytic activity in the presence of light whereby removing 90% of MB within 80 min. Moreover, the antibacterial activity of synthesized nanocomposite was examined in both visible light and dark conditions. The experiment showed that nanomaterial depicts enhanced antibacterial activity in light in comparison to dark. The results showed that the inhibition diameter of Ag/ZnO nanocomposite in light was found to be 18 (±0.2), 22 (±0.3) against E. coli and S. aureus respectively. The inhibition zone of the said nanomaterial against E. coli and S. aureus in dark was 11 (±0.3), 14 (±0.5) respectively. These results conclude that activity is delivered both in the presence of visible light and dark but efficiency of antibacterial activity is found to be more in visible light in comparison.

Phytoassisted synthesis and characterization of palladium nanoparticles (PdNPs); with enhanced antibacterial, antioxidant and hemolytic activities.

With increasing demand for the treatment of microbial resistance around the globe, it is necessary to develop metallic nanoparticles , ideally by the use of nontoxic medium i.e. plant constituents, that could arrest the microbial growth. For this reason, small and highly crystalline PdNPs were effectively synthesized by using Eryngium caeruleum leaf extract as both the reducing and capping agent. During the synthesis of PdNPs, the size and shape were made controlled by using different solvents i.e., ethanol, methanol and aqueous extract of Eryngium caeruleum. A series of physicochemical characterizations were applied to inquire the synthesis, crystal structure, particles size, and surface morphology of PdNPs. Furthermore, the PdNPs demonstrated excellent potential for the inactivation of gram-positive and gram-negative bacteria, where the methanol-PdNPs exhibited maximum growth inhibition zones against tested bacteria as compared to ethanol-PdNPs and aqueous-PdNPs. Besides, PdNPs showed better antioxidant activity to effectively scavenge 2, 2 diphenyl-1-picrylhydrazyl (DPPH). More importantly, the synthesized PdNPs are not only active for ROS generation but also show no hemolytic activity. We believe that this greener approach uncovered the useful and efficient applications of highly active PdNPs and their biocompatibility.

Photoinhibition and photocatalytic response of surfactant mediated Pt/ZnO nanocomposite.

Water pollution and bacterial resistance are universal problems. Drugs and protocols have been employed to deal with involved microbes and pollutants but these customary chemicals have many limitations. It is essential to produce new methods and materials to deal with these deleterious microbes. In the present contribution, highly efficient and stable nanocomposite of platinum activated zinc oxide was synthesized by a new plant extract and surfactant assisted protocol. The cetylpyridinium chloride was applied as surfactant to obtain high dispersion of spherical ZnO. The platinum ions were reduced on the ZnO surface by the use of Rhazya stricta plant extract. The prepared nanomaterial was used for photoinactivation of multidrug resistant bacterium Escherichia coli (E. coli). The synthesized nanomaterial showed strong E. coli inhibition efficiency in the presence of light and the observed diameter of zone of inhibition was 21 ±0.4. The effect of light on the inhibition of E.coli was studied by measuring the activated oxygen radicals inside the bacterium cell. The surface morphology of E.coli before and after treatment with Pt/ZnO was studied by SEM. Such effect was not observed in dark. The toxicity of the synthesized nanomaterials was also studied through haemolytic activity and the result shows that the nanomaterial prepared by the said method has very low toxicity. The photocatalytic degradation of methylene blue (MB) was also investigated in the presence of the synthesized nanomaterials. Effect of different parameters such as concentration of Pt/ZnO, Irradiation time and dye concentrations were also studied. An incredible photocatalytic deprivation of MB (98 %) was observed for Pt/ZnO nanocomposite as compared to individual Pt (48%) and ZnO (71%) nanoparticles after 5 minutes of irradiations. Further research is required to investigate the applications of Pt/ZnO nanocomposite.

A Tagetes minuta based eco-benign synthesis of multifunctional Au/MgO nanocomposite with enhanced photocatalytic, antibacterial and DPPH scavenging activities.

In this research work, facile, economical and eco-benign experimental procedure were adopted to synthesize Au/MgO nanocomposite with the help of Tagetes minuta leaves extract. Phytochemicals present in the leaves of Tagetes minuta were acting as reducing and stabilizing agents to avoid aggregation of nanomaterials during the preparation of Au/MgO nanocomposite. The biologically synthesized nanocomposite were systematically characterized by UV-vis spectroscopy, Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared microscopy (FTIR), High resolution transmission electron microscopy (HRTEM), Thermogravimetric analysis (TGA), dynamic light scattering (DLS) and elemental mapping. UV-visible spectrum confirmed the presence of MgO and Au due to the presence of two SPR peaks at 315 nm and 528 nm, respectively. Moreover, the Au/MgO nanocomposite exhibited superior photocatalytic, antibacterial, hemolytic, and antioxidant activities. Photocatalytic performance tests of Au/MgO nanocomposite were- appraised by the rapid degradation of the methylene blue (MB) under UV light illumination. More importantly, after four successive cycles of MB degradation, the photocatalytic efficacy remained unchanged, which ensures the stability of the Au/MgO nanocomposite. Furthermore, the antibacterial tests showed that the advanced nanocomposite inhibited the growth of Escherichia coli, Bacillus subtilis, and Staphylococcus aureus with zones of inhibition 18 (±0.3), 21 (±0.5), and 19 (±0.4) mm, respectively. The cytotoxicity study revealed that Au/MgO nanocomposite is nontoxic to ordinary healthy RBCs. Interestingly, the Au/MgO nanocomposite also possesses an excellent antioxidant activity, whereby effectively scavenging 82% stable and harmful DPPH. Overall, the present study concludes that eco-benign Au/MgO nanocomposite has excellent potential for the remediation of bacterial pathogens and degradation of MB.

Biomedical response under visible-light irradiation promoted by new hydrothermally synthesized SiO2-Zn@Fe2O3 nanofibers.

In the presence of Fe3O4 nano-fibers, we prepared SiO2-Zn@Fe2O3 hybrid Nano-fibers through a novel and simple one-pot redox reaction between ZnSO4 & SiO2. The Fe3O4 exterior nano-fibers would be homogenously covered by SiO2 coating to arrange a distinctive core-shell construction and then Zn nanoparticles are intercalated in the covering of SiO2. The synthesized nanofibers were tested for photodegradation of methylene blue (MB). The result showed that 99 % MB was degraded in 60 min. Furthermore, the antibacterial potential of SiO2-Zn@Fe2O3 nanofibers was tested against E. coli and S. aureus bacteria both in light and dark. The impact of different analysis such as Reactive oxygen species (ROS) analysis, irradiation effect on bacterial inhibition, concentration effect of SiO2-Zn@Fe2O3 nanofibers and reduction of DPPH studied. The findings clearly demonstrate that ROS is produced in the presence of SiO2-Zn@Fe2O3 nanofibers in bacterial cells and is responsible for their inhibition. Findings have shown that synthesized nanostructures can also increase the stability of DPPH radicals with increasing concentrations of nanomaterials, making them a strong candidate for DPPH reduction. The overall results show that the efficacy of SiO2-Zn@Fe2O3 nanofibers for inhibition was more pronounced than that of individual iron oxides.

Photo-assisted inactivation of highly drug resistant bacteria and DPPH scavenging activities of zinc oxide graphted Pd-MCM-41 synthesized by new hydrothermal method.

A major current biomedical challenge is to find materials that are specific, have high efficiency and with long lasting stability to serve as antimicrobial agents. In this contribution we examined new bifunctional nanostructural materials (ZnO/Pd-MCM-41) which were synthesized by a new hydrothermal procedure. To deposit active cites i.e. ZnO, a new protocol was followed in which catechol was used as a precipitating agent. Results indicated that nanostructures comprising palladium nanocrystals of a small size dispersed consistently within the hexagonal pores of the MCM-41 and also ZnO was successfully coated on mesoporous Pd-MCM-41 and that the mesoporous Pd-MCM-41 structure has been well-maintained upon modification of ZnO. The ZnO/Pd-MCM-41 is promising antibacterial agent and have efficient light inhibition activity towards Escherichia coli (E. coli), Psedomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The inhibition zone of irradiated ZnO/Pd-MCM-41 nanostructure against E. coli, P. aeruginosa and S. aureus were (17 ± 0.4) mm, 18 (±0.4) mm and 22 (±0.2) mm respectively while that in dark were (9 ± 0.5) mm, 11 (±0.3) mm and 13 (±0.4) mm respectively. The production of reactive oxygen species and hemolytic assay were also analyzed. Different parameters affecting the photo-inhibition efficiency of ZnO/Pd-MCM-41 were also studied. Likewise, the antioxidant activity of these nanostructures was studied against DPPH stabilization. Results indicated that the synthesized nanostructures are highly active and stabilized 99 % DPPH at very low concentration i.e. 1.4 mg/mL.

A facile fabrication of silver/copper oxide nanocomposite: An innovative entry in photocatalytic and biomedical materials.

In this work, principles and techniques of green chemistry were implemented which exploit environmentally and economically friendly methods using an accessible and non-toxic medium, that is water and ascorbic acid (Vit.C), which leads to the synthesis of silver/ copper oxide (Ag/CuO) nanocomposite. Vit.C was used to furnish the synthesis of excellent and controlled crystalline silver nanoparticles (AgNPs), copper oxide (CuO) and Ag/CuO nanocomposite. Moreover, the structures of all the synthesized nanomaterials were confirmed by wide range of characterization techniques which include UV-vis spectroscopy, FTIR, X-ray diffraction and Electron Diffraction Spectroscopy. However external and internal morphology of newly synthesized nanomaterials were examined by using Scanning Electron Microscopy and High resolution Transmission Electron Microscopy, respectively. The prepared nanomaterials were evaluated for catalytic decomposition of methyl orange (MO) in dark, visible light and UV light. The results showed that 20 %, 50 % and 90 % degradation of MO in 40 min was observed in dark, visible light and UV light, respectively. To further explore the biological potential of synthesized Ag/CuO nanocomposite, we also evaluated it for an inactivation of bacteria where Escherichia coli has 17(±0.5 mm) and Staphylococcus aureus has 20 (±0.6 mm) zone of inhibition in light. The results showed that reactive oxygen species (ROS) were produced in the presence of light and Ag/CuO. These ROS are the main source of inactivation of bacteria. The prepared nanomaterial has also good efficiency against DPPH stabilization. Further study is required to investigate the hidden applications of the as synthesized nanomaterials.

Biogenic metal nanoparticles as a potential class of antileishmanial agents: mechanisms and molecular targets.

Leishmaniasis, a category 1 disease, has remained neglected for decades, and therefore, has developed into a severe health problem worldwide. Unfortunately, the available antileishmanial drugs are limited, and the parasites have shown an inevitable resistance toward most of these drugs. All these factors pose a barrier to control the parasite at present. Hence, new strategies are needed to develop more effective and less toxic nanomedicines that could treat and manage the Leishmania parasite. One of these effective strategies is to construct nanometals with biologically active molecules that could possess dynamic antileishmanial activities with desirable biocompatibility. In this review paper, antileishmanial potencies of different metal nanoparticles, with particular emphasis on biogenic metal nanoparticles from 2011 to 2019, are summarized. The mechanisms by which metal-based nanomedicines kill Leishmania are also discussed.