hayrunnisa nadaroglu

Silica fume, also known as micro silica, is a by-product of the reduction of high-purity quartz with coal in electric furnaces in the production of silicon and ferrosilicon alloys. This material and laccase-modified silica fume used as alternative low-cost adsorbent materials for dye removal from aqueous solutions. The silica fume was modified to maximize its adsorption capacity. For this purpose, the laccase enzyme was purified and immobilized on silica fume. Batch adsorption experiments have been performed as a function of pH, contact time, temperature, and adsorbent dosage. The equilibrium data were analyzed using Langmuir and Freundlich adsorption isotherms. The Langmuir adsorption model provided a better fit to the data. The kinetic data were evaluated with pseudo-first-order and pseudo-second-order kinetic models. The adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R2. The thermodynamic parameters such as free energy, enthalpy, and entropy were also determined. These parameters indicated that the adsorption of Acid Fuchsin dye onto silica fume and laccase-modified silica fume was a spontaneous, endothermic, and entropy-driven process. The results show that both of them, especially laccase-modified silica fume, can be used as alternative low-cost adsorbents for dye removal from aqueous colored solutions or effluents.

It is seen that metal nanoparticles are used in many areas due to their antimicrobialeffects. For this reason, our study focused on the production of a-Fe2O3, NiOand CoO NPs of golden nanoparticles, which are easily obtained with the use ofErzincan grape extract, safe to use, environmentally friendly and cost-effective.Metal ions synthesized by the green synthesis method were characterized usingthe Scanning Electron Microscope (SEM) analysis. From the SEM diagrams ofthe synthesized nanoparticles, it was determined that the nanoparticles wereapproximately 5 to 65 nm in size. Both antimicrobial, genotoxicity and cytotoxicity effects were investigated to determine the rates at which nanoparticles can be used as biosafe. Synthesized a-Fe2O3, NiO and CoO NPs showed excellent antibacterial properties on pathogen bacteria against human. In addition, it was determined that a-Fe2O3, NiO and CoO M-NPs showed genotoxic properties in parallel with increasing concentrations. This study, as far as we know, is the first report on microbial a-Fe2O3, NiO and CoO NPs and their biological properties synthesized by this statistical approach.

Health risk assessment of nanomaterials is a new and important area emerging; obtaining nanoparticles by green synthesis method and performing cytotoxicity, genotoxicity and antimicrobial testing is an important endpoint. In vitro studies for nanoparticles (NPs) obtained by the non-toxic method offer many advantages, such as the study of the bioavailability of nanomaterials to sensitive target cells. It will be useful for investigating the toxic and genotoxic risks associated with nanoparticle exposure. In this study; silver nanoparticles (AgNPs) were synthesized by green synthesis using grape vinegar prepared by ourselves. The resulting Ag NPs were characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) methods and for different AgNPs concentrations in the range of 5-60 nm. The genotoxic effects of AgNPs were investigated using the Sister chromatid exchange (SCE) test and Micronucleus (MN) tests. Furthermore, the antibacterial and antifungal activities of the synthesized compound were tested against some pathogenic bacteria which are causative agents of the disease. As a result; it was found that the synthesized compound showed different degrees of inhibitory effect on the growth of pathogen strains compared to standard antibiotics. The findings are thought to provide clinically useful information in the treatment of many diseases using AgNPs at optimum concentrations (non-genotoxic concentrations).

In this study, the synthesis of ceria (CeO2) nanoparticles (NPs) was examined by the biosynthesis method. Then, enzyme-like features of synthesized nanoceria were examined. Peroxidase enzyme from fig (Ficus carica) was used as a synthesis and stabilizer reagent. Furthermore, it was investigated whether the obtained nanoceria has superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) activities. UV-VIS absorption spectroscopy was employed for monitoring of creation of ceria nanoparticles. The characteristics of the obtained ceria nanoparticles were studied with X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). Also, cerium oxide NPs showed enzyme-like activities, and its activities were determined with specific enzyme activity measuring methods. Surface morphology and size of the synthesized ceria were investigated by chromatographic techniques. The diameter of the biosynthesized ceria nanoparticles was determined to be 14 nm using XRD chromatogram. Advantages of unique properties of nanoceria have been promising for being enzyme-like reagent in nano-biotechnological investigations. This research explored and discussed if ceria nanomaterial s different kinds of enzymes. We examined their kinetics, mechanisms and applications, including in superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) activities. The results showed that the ceria oxide nanoparticles exhibited catalase, peroxidase and superoxide dismutase activities.