Preparation and characterization of WS2 decorated and immobilized on chitosan and polycaprolactone as biodegradable polymers nanofibers: Photocatalysis study and antibiotic-conjugated for antibacterial evaluation.

In the present work, WS2 nanoparticles and immobilized on chitosan and polycaprolactone as biodegradable polymers as photocatalyst were developed and studied for photocatalytic degradation of representative Neomycin as an aminoglycoside antibiotic. The WS2 nanoparticles were synthesized using the hydrothermal method. Further, the photocatalyst were characterized by different analytical instruments energy dispersive X-ray spectrometer (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and UV-Vis absorption spectroscopy, in order to understand their physical and optical properties. The mean crystallite sizes of WS2 nanoparticles, WS2/chitosan nanofibers and WS2/polycaprolactone nanofibers were 80.00, 70.14 and 68.71 nm, respectively. The optical absorption study revealed the presence of direct band-to-band transition with band-gap ranging from 2.0 to 1.8 eV for WS2, WS2/chitosan nanofibers and WS2/polycaprolactone nanofibers, respectively. The photocatalytic activity of the three photocatalyst was tested by UV-light-induced degradation of Neomycin antibiotic. The WS2/chitosan nanofibers and WS2/polycaprolactone nanofibers photocatalyst showed high amount of photodegradation in comparison to WS2 nanoparticles. The optimum degradation using WS2, WS2/chitosan nanofibers and WS2/polycaprolactone nanofibers occurred under UV light at pH:7 in 40 min. The bactericidal test was determined under light illumination (visible source light) and that the neomycin conjugated WS2/chitosan nanofibers and WS2/polycaprolactone nanofibers demonstrated good efficiency in antibacterial efficiency compared to pure WS2/chitosan nanofibers and WS2/polycaprolactone nanofibers.

Synthesis and characterization of Sb2S3-CeO2/chitosan-starch as a heterojunction catalyst for photo-degradation of toxic herbicide compound: Optical, photo-reusable, antibacterial and antifungal performances.

Heterostructured Sb2S3-CeO2 composites and Sb2S3-CeO2 on chitosan-starch nanocomposites have been provided with chemical manner. The characterization was performed by various instruments such as, scanning electron microscopy, Brunauer-Emmett-Teller surface area measurements, X-ray diffraction analysis, energy dispersive X-ray spectrometer and UV-Vis absorption spectroscopy. The mean crystallite sizes of CeO2, Sb2S3-CeO2 and Sb2S3-CeO2/chitosan-starch are 25.12, 51.11 and 64.12 nm, respectively. The energy band gaps of CeO2, Sb2S3-CeO2 and Sb2S3-CeO2/chitosan-starch are appraised to be 3.01, 2.41, and 2.23 eV, respectively. Photocatalytic properties of the as-prepared products for degradation of Paraquat as a toxic organic compound are investigated under UV light irradiation at room temperature. The Sb2S3-CeO2 and Sb2S3-CeO2/chitosan-starch exhibited high photocatalytic performance. Moreover, the possible mechanism of photocatalytic degradation for Paraquat was proposed. The photocatalyst as hydroxide form existing in the product provides more OH during the degradation process, as well as influences the band gap of the product due to present the electron-hole pairs. The optimum effects such as time and pH were obtained 7 and 30 min for photo-degradation process. The antibacterial and fungicidal property of Sb2S3-CeO2/chitosan-starch nanocomposites was investigated and demonstrates good efficiency in antimicrobial efficiency compared to CeO2, and Sb2S3-CeO2.

Preparation and characterization of MnS2/chitosan­sodium alginate and calcium alginate nanocomposites for degradation of analgesic drug: Photocorrosion, mechanical, antimicrobial and antioxidant properties studies.

MnS2, MnS2/Chitosan­sodium Alginate (MnS2/CS-NaAlg) and MnS2/Chitosan-Calcium Alginate (MnS2/CS-CaAlg) nanocomposites were prepared via the chemical procedure. The characterization was performed by various instruments such as energy dispersive X-ray spectrometer (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) elemental map analysis, Fourier transform infrared spectrometry (FT-IR), Brunauer-Emmett-Teller (BET) surface area measurements, UV-Vis absorption spectra and X-ray absorption spectroscopy. The mean crystallite sizes of MnS2, MnS2/CS-NaAlg and MnS2/CS-CaAlg are 60.12, 71.25 and 74.54 nm, respectively. From Kubelka-Munk equation, the energy band gaps of MnS2, MnS2/CS-NaAlg and MnS2/CS-CaAlg are estimated to be 2.83, 2.71 and 2.41 eV, respectively. The investigation of photocatalysis properties was performed by degradation of tramadol under UV light illumination. The optimum of experimental variables such as pH and time on photo-degradation were found 3 and 60 min, respectively. The results show that the efficiency photocatalysis of MnS2/CS-NaAlg and MnS2/CS-CaAlg nanocomposites under was higher than MnS2. The antibacterial and fungicidal property of MnS2/CS-NaAlg and MnS2/CS-CaAlg nanocomposites was investigated and demonstrates good efficiency in antimicrobial efficiency compared to MnS2. The MnS2, MnS2/CS-NaAlg and MnS2/CS-CaAlg have been shown excellent mechanical and antioxidant properties.

Degradation of macrolide antibiotics via sono or photo coupled with Fenton methods in the presence of ZnS quantum dots decorated SnO2 nanosheets.

The ZnS quantum dots decorated SnO2 nanosheets were prepared by a hydrothermal synthesis method. The characteristic structure of ZnS QDs/SnO2 nanocomposites was analyzed using several instruments such as X-ray diffraction, transmittance electron microscopy, atomic force microscopy, X-ray photoelectron and UV-vis and photoluminescence spectroscopy. The average diameters of SnO2 nanosheets and ZnS QDs/SnO2 nanocomposites were 12.5 and 3.6 nm, respectively. The merits of sono-photo-Fenton treatment process were investigated using degradation of Roxithromycin. The process involved ultrasound and UV irradiation, and hydrogen peroxide generated in situ. The treatment performance of the US/UV/catalyst process was superior to the constituent processes and synergistic mechanisms in the US/UV/catalyst process were the result of the promotion of hydroxyl radical generation. For the constituent processes, the US/catalyst system showed to the best efficiency with used catalyst compared to the conventional Fenton reaction. It was also observed that the addition of catalyst to the test solution undergoing UV irradiation substantially improved Roxithromycin and clarithromycin degradation. The best experimental conditions for efficient CLA and RXM degradation in the US/UV/catalyst/H2O2 system were pH0 3, hydrogen peroxide concentration of 6 mmol L-1, ZnS QDs/SnO2 nanocomposites dose of 0.3 g L-1 and ultrasonic power of 75 W. The antibacterial experiment was investigated under visible light illumination and the ZnS QDs/SnO2 nanocomposite showed good efficiency as antibacterial.

Microwave-assisted photocatalysis of neurotoxin compounds using metal oxides quantum dots/nanosheets composites: Photocorrosion inhibition, reusability and antibacterial activity studies.

Water pollution caused by different pollutants is one of the challenging tasks for the scientific community. We have prepared and characterized a material for removal of pollutant compounds. ZnO quantum dots decorated CuO nanosheets and TiO2 quantum dots decorated WO3 nanosheets composites have been prepared using a hydrothermal method. The as synthesized catalysts were characterized by various techniques. The crystallite sizes of CuO NSs and WO3 NSs were to be obtained 12.5 and 13.25nm and when dopped with ZnO and TiO2 size reduces to 3.2 and 3.9nm, respectively. The energy band gap of the CuO NSs, WO3 NSs, ZnO QDs/CuO NSs and TiO2 QDs/WO3 NSs composite are calculated to be 2.01, 2.61, 1.86 and 2.32eV, respectively. The prepared catalysts are efficiently utilized for the photocatalytic degradation of two neurotoxin compounds under UV and UV coupled with microwave irradiation. The prepared catalyst composites reveal excellent photocatalytic degradation of neurotoxin compound by degrading it up to 75% under UV and UV/microwave irradiation. The photocalysis efficiency in UV/microwave system is higher than UV system. The result shows that the ZnO QDs/CuO NSs and TiO2 QDs/WO3 NSs composites have excellent photocorrosion inhibition and reusability properties. Thus, prepared samples with positive surface potential upon interaction with negative surface potential of Enterococcus faecalis and Micrococcus luteus.

Preparation and characterization of Fe3O4-Ag2O quantum dots decorated cellulose nanofibers as a carrier of anticancer drugs for skin cancer.

The Best performance drug delivery systems designed with Fe3O4-Ag2O quantum dots decorated cellulose nanofibers which that grafted with Etoposide and Methotrexate. Morphology properties were characterized by Scanning and Transmittance electron microscopy. The crystalline structure of prepared sample was evaluated using by X-ray diffraction. The vibrating sample magnetometer analysis was used for magnetic behavior of samples. The size distributions of Fe3O4-Ag2O QDs/Cellulose fibers nanocomposites indicate that the average diameter was 62.5nm. The Saturation magnetization (Ms) indicates the Fe3O4-Ag2O QDs/Cellulose fibers nanocomposites have ferromagnetic properties in nature. For make carrier, the Iron and Silver should be binds to cellulose nanofibers and to drug molecules and observe in UV-vis spectroscopy. The drug release kinetics was studied in vitro as spectrophotometrically. The release of Etoposide and Methotrexate were carried out with a constant speed, and the equilibrium reached at 24 and 30h with a total amount 78.94% and 63.84%, respectively. The results demonstrated that the obtained Fe3O4-Ag2O quantum dots/cellulose fibers nanocomposites could be applied for drug delivery systems. Cytotoxicity and antioxidant study confirmed the activity of the drug incorporated in nanocomposites. In addition, the cytotoxicity of drug was increased when loaded on nanocomposites, compared to pure Fe3O4-Ag2O quantum dots/cellulose fibers nanocomposites.

Ultraviolet/ultrasound-activated persulfate for degradation of drug by zinc selenide quantum dots: Catalysis and microbiology study.

In this study, wet chemical method used for ZnSe quantum dots (QDs) and characterized by, UV-vis, photoluminescence spectroscopy, X-ray diffraction and transmission electron microscopy. The crystallites size of ZnSe QDs was 4.0nm. The average diameters of ZnSe QDs were 3.0-5.3nm. Ritalin was degraded using the UV/ZnSe QDs/persulfate process. The several parameters investigated for the influence of Rtialin degradation were the temperature, the persulfate concentration, and the initial Ritalin concentration. The values of optimum parameters ware room temperature, concentration persulfate 5mmol/L and initial Ritalin concentration 0.09mmol/L. Comparative analyses showed the maximum degradation of Ritalin was found for ZnSe/persulfate under ultra-visible and ultra-sonic irradiation process. Comparative analysis showed the maximum degradation of Ritalin was found for ZnSe/persulfate under ultra-visible and ultra-sonic irradiation process. The values of first-order rate constants from degradation of Ritalin at 25°C were 0.96×10-2, 1.09×10-2, 1.59×10-2 and 2.19×10-2 for US/PS, UV/PS, ZnSe/US/PS and ZnSe/UV/PS system, respectively. The antibacterial activity evaluation against two bacterials, including Gram-positive bacteria Staphylococcus aureus (ATCC 43300), Bacillus megaterium (ATCC 14581) and Gram-negative bacteria Pseudomonas aeruginosa (ATCC 27853), Micrococcus luteus (ATCC 4698) was considered. It was found that the MIC values for the antibacterial assay in the presence of ZnSe QDs were around 0.30mM with 64.0, 66.0, 79.2, and 83.5% inhibition for the S. aureus, B. megaterium, P. aeruginosa and M. luteus bacterial strains, respectively. Then, results show that the ZnSe QDs have antibacterial activity.

Zn doped CdO nanoparticles: Structural, morphological, optical, photocatalytic and anti-bacterial properties.

Pure and zinc-doped CdO NPs (Zn-CdO NPs) were synthesized through a facile co-precipitation method. The structural, morphology, chemical composition, optical and antibacterial activity of the NPs were studied with respect to pure and Zn-doped CdO concentration (0-7.5mol.%). Scanning electron microscope (SEM) images reveal that pure and Zn-doped CdO NPs were in the nano-scale regime with different crystalline morphology. The energy dispersive X-ray spectroscopy (EDS) spectrum predicts the presence of Cadmium (Cd), Zinc (Zn) and Oxygen (O) in the prepared samples. Optical studies divulge that Zn2+ doping CdO decreases the band gap energy (Eg) (3.36-3.02eV) with an increase in Zn2+ doping concentration. Optical absorption spectrum of CdO red-shifted as the Zn concentration varied from 2.5mol.% to 7.5mol.%. PL spectra displayed a strong UV emission peak at 380nm. Enhanced Visible emission at 430 and 522nm with Zn2+ doping interprets the defect density in CdO by occupying Cd2+ vacancies with Zn2+ ions. Photocatalytic studies revealed that 7.5% Zn-doped CdO NPs show maximum degradation for atrazine (ATZ) as herbicide pollution under UV irradiation. Antibacterial studies against (Gram positive) and (Gram negative) bacteria's authenticate that Zn2+ doped CdO nanostructures exhibit excellent antibacterial activity against all bacteria's with an increase in doping concentration.

Synthesis and characterization of core-shell bimetallic nanoparticles for synergistic antimicrobial effect studies in combination with doxycycline on burn specific pathogens.

Nano-medicine is a breakthrough discovery in the healthcare sector. Doxycycline is a new generation antibiotic which is proved to be a boon in the treatment of patients with complicated skin infections. We have tried to explore the benefits of synthesized bimetallic silver-gold nanoparticles in combination with new generation antibiotic for burn infections. The bimetallic nanoparticles synthesized by core-shell method were characterized using scanning electron microscopy equipped with an energy dispersive spectrometer, transmission electron microscopy, X-ray diffraction and UV-Vis spectroscopy. The calculated average particle sizes of the Ag-Au NPs were found to be 27.5nm. The Ag-Au core-shell BNPs show a characteristic Plasmon peak at 525nm which is broad and red shifted. The synergistic antimicrobial activity of doxycycline conjugated bimetallic nanoparticles was investigated against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Micrococcus luteus. This combined therapeutic agent showed greater bactericidal activity. Synergy of antibiotic with bimetallic nanoparticles is quite promising for significant application in burn healing therapy. The mechanism of the antibacterial activity was studied through the formation of reactive oxygen species (ROS) that was later suppressed with antioxidant to establish correlation with the Ag-Au NPs antimicrobial activity. Ag-Au NPs showed effective antiproliferative activity toward A549 human lung cancer (CCL-185) and MCF-7 human breast cancer (HTB-22) cell lines.