Browsing by Author "Bekmezci, M."

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Characterisation, Antibacterial and Antioxidant Effects of Mountain Tea (Sideritis L.) Mediated Silver Nanoparticles in Preventing Dna Damage
(Springer, 2025) Gur, T.; Bekmezci, M.; Meydan, I.; Seckin, H.; Sen, F.
Nanoparticle-based products formed by combining atomic and molecular level materials find their place in many fields such as industry, cosmetics, medicine and pharmacy. In our study, we synthesised Ag NPs from mountain tea (Sideritis L.) using green chemistry method and demonstrated their material properties by characterisations such as SEM, EDX, FT-IR, XRD and UV-Vis spectroscopy. It was observed that the obtained silver nanoparticles formed inhibition zone diameters of 18 mm, 10 mm and 10 mm against Bacillussubtilis ATCC 6633, Pseudomonasaeruginosa ATCC 27853 and Staphylococcusaureus ATTC 29213 bacteria, respectively. Candidaalbicans ATTC 90028 pathogen, which we used as a fungus, formed a zone diameter of 10 mm. In addition the effect of Ag NPs against DNA damage was determined by gel electrophoresis method. In the images, it is seen that the damaged DNA in the 2 end well is preserved due to the increase in concentration. The effects of Ag NPs used in the 5th and 6 th wells are much better seen compared to the others. Ag NPs showed strong resistance to possible DNA damage. DPPH method was used to investigate the antioxidant effects of AgNPs produced by green synthesis, which is a biological procedure, and as a result, the radical quenching activity of mountain tea was found to be quite good with a value of 80% compared to the positive control BHA. We hope that Ag NPs synthesised from mountain tea, whose structure and properties have been extensively elucidated by various methods, may have a wide range of uses that can serve humanity.
Evaluation of Antioxidant, Antibacterial and Thermal Stability Properties of Silver Nanoparticles Synthesised With Infundibulicybe Gibba Extract
(Springer, 2025) Meydan, I.; Seckin, H.; Kocak, Y.; Okumus, E.; Bekmezci, M.; Sen, F.
Mushrooms have been used by people for centuries for various purposes due to their unique taste, high nutritional content and pharmacological effects. Bioactive components in the structure of mushrooms are an important biological source for the green synthesis of silver nanoparticles (AgNPs) as reducing and stabilizing agents. In this study, AgNPs/Ig were synthesized using the mushroom species Infundibulicybe gibba. The color transformation of the formed nanoparticles from yellow to brown occurred and peaked at 370 nm in the UV-Vis spectrum. The nanoparticles had amorphous shape and their molecular characterization was determined by Fourier transform infrared spectroscopy (FTIR). AgNPs/Ig was much more stable (- 50.02 mV) and its hydrodynamic diameter was much lower (216.50 nm) compared to the mushroom extract. A significant increase in the antioxidant activity (IC50 5.66 mg/ml) and thermal stability of the formed nanoparticles was determined. Lipid peroxidation inhibition of the extract and nanoparticles was measured as IC50 value of 6.75 and 5.51 mg/ml, respectively. In the antimicrobial analysis results, while the mushroom extract did not show any inhibition against the selected microorganisms, AgNPs/Ig showed a low antimicrobial activity. As a result, the synthesis of AgNPs/Ig was carried out through green synthesis, which is environmentally friendly, safe, cost-effective, easy to use and does not contain toxic chemicals, and it has been revealed that AgNPs synthesized using this mushroom species have advantageous potential for use.
Pt-Based Catalysts for Alcohol Oxidation
(Elsevier, 2021) Burhan, H.; Arikan, K.; Bekmezci, M.; Gurc, T.; Şen, F.
The development of fuel cell technologies and the use of clean energy sources have recently accelerated considerably. Fuel cells are electrochemical devices that convert chemical energy into electrical energy with an efficiency of 40%-80%. Fuel cells have many advantages, such as high efficiency, environmental friendliness, silent operation, and light weight, and it can be applied in vehicles and power plants. A fuel cell consists of an anode, the electrolyte medium that transmits the hydrogen ion and the cathode. As the fuel feeds from the anode alcohol, the cathode meets the oxygen source for the air itself. As a result of reactions in the electrodes, electrical energy is produced and water vapor from cathode, waste fuel, and CO2 is given off from the anode as by-products. In this chapter, detailed information about the types and properties of platinum-based catalysts for the alcohol oxidation of fuel cells and their applications are provided by compiling information from the research literature. In addition, economic evaluations were made by specifying the positive and negative aspects of these materials. © 2021 Elsevier Inc. All rights reserved.
Role of Trametes Multicolor in Green Nanotechnology Based Antioxidant, Antimicrobial, Lipid Peroxidation Inhibition From Fungi To Nanoparticles
(Springer, 2024) Kocak, Y.; Okumus, E.; Meydan, I.; Seckin, H.; Bekmezci, M.; Sen, F.
Fungi as source for new-bio based materials has a wide range of potential uses in the pharmaceutical, cosmetic, and medical sectors. They contain abundant natural bioactive chemical resources. This study reports the use of Trametes multicolour (Tm) mushroom extract for the ecofriendly production of silver nanoparticles (AgNPs). The color of the mushroom extract turns dark brown after a certain period of time when combined with metal. (AgNPs/Tm) and then showed maximum absorption at 318 nm, the wavelength of the surface plasmon resonance of AgNPs. The morphology of AgNPs/Tm was spherical and an EDX peak in the 3 keV region indicated the presence of Ag atoms. The binding properties of the biocomponents involved in NPs handling and stabilising the NPs were identified using Fourier transform infrared spectroscopy (FTIR) data. The synthesized NPs exhibited much higher stability (- 37.63 mV), antioxidant activity (IC50 18.92 mg/ml) and inhibition against lipid peroxidation (IC50 7.46 mg/ml) compared to the mushroom extract. Although there was a significant decrease in the hydrodynamic diameter of the NPs, there was an increase in their thermal stability and antimicrobial activity. As a result, the existence and current potential of a new biomaterial suitable for cost-effective and large-scale production in the synthesis of AgNPs has been demonstrated for the first time.