Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 11Citation - Scopus: 10UV Light Promoted Dihydrolipoic Acid and Its Alanine Derivative Directed Rapid Synthesis of Stable Gold Nanoparticles and Their Catalytic Activity(Nature Portfolio, 2024-10-21) Temur, Nimet; Dadi, Seyma; Nisari, Mustafa; Ucuncuoglu, Neslihan; Avan, Ilker; Ocsoy, IsmailIn general, colloidal gold nanoparticles (AuNPs) have been synthesized in heated or boiling water containing HAuCl4 precursor with sodium citrate as reducing stabilizing reagent. Although temperature plays a driving for synthesis of AuNPs, elevated temperature in thermal reduction method causes aggregation of the AuNPs. The preferential, rapid and strong binding of dihydro-lipoic acid and its derivatives on surface of AuNPs via thiol - Au chemistry promote the production of very stable AuNPs. In this study, we have developed citric acid (CA), dihydrolipoic acid (DHLA) and DHLA-Alanine (DHLA-Ala) directed rapid synthesis of ultra-stable AuNPs, DHLA@AuNPs and DHLA-Ala@AuNPs, under the UV (311 nm) irradiation at room temperature (RT: 25 degrees C) in around 10 min (min). CA is used as a potential reducing agent to expedite both reduction of Au3+ ion and AuNP formation, DHLA and DHLA-Ala act as stabilizing agents by replacing CA molecules on surface of AuNPs in order to produce quite stable AuNP. It is worthy to mention that reduction of Au3+ ion, formation and surface stabilization of AuNPs are consequently occurred in one step. We also investigated how experimental parameters including reaction time and temperature, pH of reaction solution, affect formation of the AuNPs. The effects of salt concentration and storage temperature were studied to show stability of the AuNPs. The synthesized DHLA@AuNPs and DHLA-Alanine@AuNPs were characterized via UV-Vis spectrophotometer (UV-Vis), scanning transmission electron microscope (STEM), dynamic light scattering (DLS) and Zeta potential (ZT) devices. The reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was efficiently catalyzed by the AuNPs in the presence of sodium borohydride in aqueous solution.Article Citation - WoS: 5Citation - Scopus: 7Rational Design of EDTA-Incorporated Nanoflowers as Novel and Effective Endodontic Disinfection Against Biofilms(Springer, 2023-10-03) Aslan, Tugrul; Dadi, Seyma; Kafdag, Ozgur; Temur, Nimet; Ildiz, Nilay; Ocsoy, Ismail; Ustun, YakupThe ethylenediaminetetradiacetic acid (EDTA) is one of the most commonly used irrigation solutions. Although EDTA has a very low antimicrobial property, it is used to remove inorganic part of smear layer in areas of root canal system. Herein, we developed EDTA-incorporated nanoflowers (EDTA NFs), for the first time, as novel and effective irrigation solution with quite high antimicrobial property to provide complete disinfection in root canal system. We both systematically elucidated the formation of the EDTA NFs with various techniques, and their catalytic and antimicrobial activities in the presence of hydrogen peroxide (H2O2) were documented through intrinsic EDTA property and peroxidase-like activities.Book Part Citation - Scopus: 1Green Magnetic Nanoparticles in Enzyme Immobilization(Elsevier, 2024) Dadi, Seyma; Alrifai, Wardishan Kassem; Öçsoy, IsmailEnzymes as highly efficient biocatalysts are widely used in various biotechnological sectors including cosmetic, textile, food, and detergent. However, their practical applications can be hampered due to high expense and challenges in the extraction, separation, and purification steps. Additionally, enzymes have limited activity and stability at high temperature and different pH values. Aiming to overcome these challenges, various nanoparticles (NPs) have been used as supporting matrices and carriers for enzyme immobilization. Among the NPs, in recent years, green magnetic nanoparticles (GMNPs) have attracted great attention as ideal support material for enzyme immobilization owing to their exceptional properties, such as their easy preparation, low toxicity, biocompatibility, and lower diffusion limitation. These properties enable the immobilized enzymes on GMNPs to be used in many different applications. This chapter aims to summarize the recent developments about enzyme immobilization on magnetic nanoparticles and GMNPs and their practical applications. © 2024 Elsevier B.V., All rights reserved.