Adsorption and photocatalysis efficiency of magnetite quantum dots anchored tin dioxide nanofibers for removal of mutagenic compound: Toxicity evaluation and antibacterial activity.

The Magnetite Fe3O4 quantum dots anchored SnO2 nanofibers (Fe3O4 QDs/SnO2 NFs) have been synthesized using the facile one step hydrothermal method. The characteristic structure of synthesized Fe3O4 QDs/SnO2 NFs was analyzed using X-ray diffraction, Transmission electron Microscopy, Scanning electron microscopy, UV-vis diffuse reflectance, photoluminescence spectroscopy, and N2 adsorption-desorption instrumental techniques. The crystallites size of Fe3O4QDs/SnO2 NFs was 7.0nm. The average diameters of Fe3O4QDs/SnO2 NFs were 7.25nm. BET surface area of Fe3O4QDs/SnO2 NFs has been found 53.064m2/g. The activity of Fe3O4 QDs/SnO2 NFs samples were compared towards adsorption and degradation of mutagenic compound such as Ethyl methanesulfonate (EMS). The Fe3O4 QDs/SnO2 NFs demonstrates 93.85% and 56.85% photo degradation and adsorption activity towards 10ppm EMS solution in 30 and 40min, respectively. Fe3O4 QDs/SnO2 NFs shows maximum removal of EMS at pH5. Additionally, cytotoxicity test showed that the newly developed catalyst has low cytotoxic effects on three kinds of human cells. The antibacterial activity evaluation against two bacterials, including Staphylococcus aureus (ATCC 43300), and Pseudomonas aeruginosa (ATCC 27853) was considered. It was found that the MIC values for the antibacterial assay in the presence of Fe3O4 QDs/SnO2 NFs were around 0.38mM with 83.4, and 85.5% inhibition for the S. aureus, and P. aeruginosa bacterial strains, respectively.

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.

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.

Degradation photocatalysis of tetrodotoxin as a poison by gold doped PdO nanoparticles supported on reduced graphene oxide nanocomposites and evaluation of its antibacterial activity.

In this project, synthesis of pure and gold doped PdO-reduced graphene oxide nanocomposites by sonochemical and deposition-precipitation process was performed and characterized using X-ray diffraction (XRD), transmission electronic microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The specific surface area of synthesized un-doped and Au doped PdO-RGO nanocomposites is 83.2, 109.1m2g-1 and total pore volume is 0.31, 0.40cm3g-1, respectively. With Tetrodotoxin as a target pollutant, photocatalytic system of UV+photocatalyst+H2O2 was set up. Some influencing parameters, including H2O2 dosage and initial pH value were investigated and the stability of the photocatalyst was also studied during the photocatalysis. The optimum values of operating parameters were found at an initial pH value of 5.0, a H2O2 dosage of 0.15mmol/L-1 and photocatalyst dosage of 0.08g. Under the optimal conditions, the highest removal rate of Tetrodotoxin achieved 95%. Compared with the traditional photo-Fenton system, the UV+photocatalyst+H2O2 system can not only improve the degradation efficiency of Tetrodotoxin, but also reduce the dosage of H2O2 and thus reduce the processing cost. Antibacterial properties of un-doped and Au doped PdO-RGO nanocomposites were investigated by gram negative bacteria Escherichia coli and gram positive Staphylococcus aureus. The results showed that the antibacterial activity enhanced by Au PdO-RGO nanocomposites.