WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Disorder-Engineered Hybrid Plasmonic Cavities for Emission Control of Defects in hBN(American Chemical Society, 2026) Genc, Sinan; Yucel, Oguzhan; Aglarci, Furkan; Rodriguez-Fernandez, Carlos; Yilmaz, Alpay; Caglayan, Humeyra; Bek, AlpanDefect-based quantum emitters in hexagonal boron nitride (hBN) are promising building blocks for scalable quantum photonics due to their stable single-photon emission at room temperature. However, enhancing their emission intensity and controlling the decay dynamics remain significant challenges. This study demonstrates a low-cost, scalable fabrication approach to integrate plasmonic nanocavities with defect-based quantum emitters in hBN nanoflakes. Using the thermal dewetting process, we realize two distinct configurations: stochastic Ag nanoparticles (AgNPs) on hBN flakes and hybrid plasmonic nanocavities formed by AgNPs on top of hBN flakes supported on gold/silicon dioxide (Au/SiO2) substrates. While AgNPs on bare hBN yield up to a 2-fold photoluminescence (PL) enhancement with reduced emitter lifetimes, the hybrid nanocavity architecture provides a dramatic, up to 100-fold PL enhancement and improved uniformity across multiple emitters, all without requiring deterministic positioning. Finite-difference time-domain (FDTD) simulations and time-resolved PL measurements confirm size-dependent control over decay dynamics and cavity-emitter interactions. Our versatile solution overcomes key quantum photonic device development challenges, including material integration, emission intensity optimization, and spectral multiplexity.Article Lapatinib-Loaded ZIF-8 Nanoparticles: a Multifunctional Drug Delivery System With Anticancer, Antibacterial, and Antioxidant Properties(American Chemical Society, 2025) Aslan, Ezgi; Sanli-Mohamed, GulsahThe pitfalls of conventional chemotherapy, including poor solubility, off-target toxicity, and multidrug resistance, have driven the development of nanoparticle-based delivery systems. Here, we report the facile one-pot synthesis of lapatinib-encapsulated zeolitic imidazolate framework-8 (LAP@ZIF-8) nanoparticles. The formulation achieved an encapsulation efficiency of 72.4% and a drug loading capacity of 6.6%. Comprehensive physicochemical characterization confirmed uniform hexagonal morphology (SEM), favorable hydrodynamic size (236 +/- 2 nm; DLS), positive surface charge (+29 mV; zeta-potential), high crystallinity (XRD), and excellent thermal stability (TGA). LAP release was pH-responsive, with similar to 77% cumulative release at pH 5.5 (tumor-mimicking) versus 43% at pH 7.4 after 96 h. Serum-protein binding (<11%) and hemolysis (<2%) assays demonstrated good biocompatibility. In vitro, LAP@ZIF-8 exhibited potent, selective cytotoxicity toward HER2-positive SK-BR-3 breast-cancer cells (72 h IC50 = 1.2 mu g mL-1) while sparing HER2-negative MCF-7 cells. Importantly, both free LAP and LAP@ZIF-8 were well-tolerated by nontumorigenic MCF-10A mammary epithelial cells: viability remained >= 90% at <= 1 mu g mL-1 and exceeded 50% even at 100 mu g mL-1, indicating that the IC50 was not reached and providing a preliminary safety window for healthy tissues. Beyond its anticancer effects, the nanocarrier displayed broad-spectrum antibacterial activity (minimum bactericidal concentrations: 5 mg mL-1 for Staphylococcus aureus and 10 mg mL-1 for Escherichia coli) and moderate antioxidant capacity (DPPH IC50 = 666 mu g mL-1). Collectively, these results position LAP@ZIF-8 as a versatile, pH-sensitive platform that combines selective anticancer efficacy with low toxicity to healthy cells alongside ancillary antibacterial and antioxidant properties suitable for multimodal therapy.Article Sandwich-Structured Coating for Ultraviolet Protection and Thermal Management Applications(American Chemical Society, 2025) Kartal, U.; Yurddaskal, M.During the day, exposure to UV radiation poses risks to human health, while managing heat exchange is important for comfort in protective textiles. Recently, infrared-reflective materials have attracted attention, particularly for reducing the infrared transmission and moderating the thermal emission. In this study, titanium dioxide/copper–aluminum/titanium dioxide (TiO<inf>2</inf>/Cu–Al/TiO<inf>2</inf>, TCAT) sandwich-structured coatings were deposited on polyester fabric using magnetron sputtering. Deposition times (40 and 90 s) were varied to adjust Al and Cu layer thicknesses between 20 and 55 nm, and the resulting films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV–vis spectroscopy, and thermal imaging. The coatings retained moderate visible transmittance on glass, whereas on woven polyester fabric, they formed an optically dense barrier with near-zero UV transmittance, suppressing light penetration across the visible to near-infrared (VIS–NIR) range. In conjunction with the emissivity-aware interpretation of thermography, these results substantiate substrate-independent UV shielding and optical/thermal barrier behavior of the TCAT multilayer. Thermal imaging qualitatively indicated reduced apparent surface temperature for coated fabrics compared to uncoated ones, suggesting partial thermal shielding. These results demonstrate the feasibility of integrating multifunctional coatings into daily-use polyester textiles, offering effective UV protection and the potential for thermal management in protective applications. © 2025 The Authors. Published by American Chemical SocietyArticle Time-Resolved Stokes Polarization Analysis of Single Photon Emitters in Hexagonal Boron Nitride(American Chemical Society, 2025) Samaner, C.; Ateş, S.Solid-state quantum emitters are pivotal to the advancement of quantum technologies, particularly in quantum computation and communication, where the polarization of single photons serves as a key information carrier. Precise characterization of polarization is essential for understanding the underlying dynamics and minimizing polarization-related errors in emitter design. In this study, we employ the Rotating Quarter-Wave Plate (RQWP) method to perform comprehensive polarization analysis of quantum emitters in hexagonal boron nitride (hBN). By capturing both time-averaged and time-resolved polarization characteristics, we present the first demonstration of dynamic Stokes parameter evolution from single-photon emitters in hBN. Our work demonstrates a powerful method for revealing complex polarization dynamics that were previously inaccessible and provides new insights into the behavior of solid-state quantum emitters. The methods introduced here are broadly applicable to polarization studies across a range of solid-state quantum systems. © 2025 Elsevier B.V., All rights reserved.Article Citation - WoS: 7Citation - Scopus: 7Breaking the Boundaries of the Goldschmidt Tolerance Factor With Ethylammonium Lead Iodide Perovskite Nanocrystals(American Chemical Society, 2024) Güvenç, Çetin Meriç; Toso, Stefano; Ivanov, Yurii P.; Saleh, Gabriele; Balcı, Sinan; Divitini, Giorgio; Manna, LiberatoWe report the synthesis of ethylammonium lead iodide (EAPbI3) colloidal nanocrystals as another member of the lead halide perovskites family. The insertion of an unusually large A-cation (274 pm in diameter) in the perovskite structure, hitherto considered unlikely due to the unfavorable Goldschmidt tolerance factor, results in a significantly larger lattice parameter compared to the Cs-, methylammonium- and formamidinium-based lead halide perovskite homologues. As a consequence, EAPbI3 nanocrystals are highly unstable, evolving to a nonperovskite delta-EAPbI3 polymorph within 1 day. Also, EAPbI3 nanocrystals are very sensitive to electron irradiation and quickly degrade to PbI2 upon exposure to the electron beam, following a mechanism similar to that of other hybrid lead iodide perovskites (although degradation can be reduced by partially replacing the EA+ ions with Cs+ ions). Interestingly, in some cases during this degradation the formation of an epitaxial interface between (EA x Cs1-x )PbI3 and PbI2 is observed. The photoluminescence emission of the EAPbI3 perovskite nanocrystals, albeit being characterized by a low quantum yield (similar to 1%), can be tuned in the 664-690 nm range by regulating their size during the synthesis. The emission efficiency can be improved upon partial alloying at the A site with Cs+ or formamidinium cations. Furthermore, the morphology of the EAPbI3 nanocrystals can be chosen to be either nanocube or nanoplatelet, depending on the synthesis conditions.Article Citation - WoS: 2Citation - Scopus: 2Exploring Noncentrifugal Sugar as a Partial Replacement for White Sugar in Low Methoxyl Pectin Confectionery Gels: Impacts on Physical and Rheological Properties(American Chemical Society, 2024) Fakhar, Hafiz Imran; Çavdaroğlu, Elif; Hayat, Muhammad Qasim; Janjua, Hussnain A.; Oztop, Mecit HalilNoncentrifugal sugar (NCS) is an unrefined, dark brown sugar containing minerals and plant secondary metabolites, unlike refined white sugar (WS). This study explored using NCS in confectionary jellies as an alternative sugar. We used different concentrations of NCS and WS to prepare low methoxyl pectin (LMP) confectionery gels characterized by their physical and rheological properties along with time-domain nuclear magnetic resonance (TD-NMR) relaxometry. The strongest LMP gel, with a hardness of 0.94 N, was achieved by substituting 25% of WS with NCS at a low CaCl2 concentration (0.075 M). Gels with up to 50% WS replaced by NCS showed comparable hardness to standard LMP gels made solely with WS at a 0.15 M CaCl2 concentration, attributed to NCS's unique constituents. The NCS-WS gel exhibited the shortest T2 values (139.8 ms) and self-diffusion coefficient values (4.99 x 10-10 m2/s), indicating a denser, more cross-linked structure that restricted water mobility. These findings suggest NCS's complex role in affecting LMP gels' chemical and physical properties, highlighting its potential as a partial WS replacement in LMP gelation-based products, with an additional source of minerals and antioxidants.Article Citation - WoS: 13Citation - Scopus: 11Bottom-Up Synthesis of Platinum Dual-Atom Catalysts on Cerium Oxide(American Chemical Society, 2024) Mekkering, Martijn J.; Laan, Petrus C. M.; Troglia, Alessandro; Bliem, Roland; Kızılkaya, Ali Can; Rothenberg, Gadi; Yan, NingWe present here the synthesis and performance of dual-atom catalysts (DACs), analogous to well-known single-atom catalysts (SACs). DACs feature sites containing pairs of metal atoms and can outperform SACs due to their additional binding possibilities. Yet quantifying the improved catalytic activity in terms of proximity effects remains difficult, as it requires both high-resolution kinetic data and an understanding of the reaction pathways. Here, we use an automated bubble counter setup for comparing the catalytic performance of ceria-supported platinum SACs and DACs in ammonia borane hydrolysis. The catalysts were synthesized by wet impregnation and characterized using SEM, HAADF-STEM, XRD, XPS, and CO-DRIFTS. High-precision kinetic studies of ammonia borane hydrolysis in the presence of SACs show two temperature-dependent regions, with a transition point at 43 degrees C. Conversely, the DACs show only one regime. We show that this is because DACs preorganize both ammonia borane and water at the dual-atom active site. The additional proximal Pt atom improves the reaction rate 3-fold and enables faster reactions at lower temperatures. We suggest that the DACs enable the activation of the water-O-H bond as well as increase the hydrogen spillover effect due to the adjacent Pt site. Interestingly, using ammonia borane hydrolysis as a benchmark reaction gives further insight into hydrogen spillover mechanisms, above what is known from the CO oxidation studies.Article Citation - WoS: 2Citation - Scopus: 3Nkx3.1 Expression Contributes To Epithelial-Mesenchymal Transition of Prostate Cancer Cells(American Chemical Society, 2023) Saydullaeva, Iroda; Debeleç Bütüner, Bilge; Korkmaz, Kemal SamiStudies demonstrate that inflammation synergizes with highgrade aggressive prostate tumor development and ultimately metastatic spread, in which a lot of work has been done in recent years. However, the clear mechanism of inflammation inciting prostate cancer remains largely uncharacterized. Our previous study has shown that the conditioned media (CM)-mediated LNCaP cell migration is partially correlated with the loss of expression of the tumor suppressor NKX3.1. Here, we continue to investigate the inflammation-mediated migration of prostate cancer cells, and the role of NKX3.1 in this process to gain insights into cell migration-related changes comprehensively. Earlier, the model of inflammation in the tumor micro environment have been optimized by our research group; here, we continue to investigate the time-dependent effect of CM exposure together with NKX3.1 changes, in which we observed that these changes play important roles in gaining heterogeneous epithelial-to-mesenchymal transition (EMT) phenotype. Hence, this is an important parameter of tumor progression; we depleted NKX3.1 expression using the CRISPR/Cas9 system and examined the migrating cell clusters after exposure to inflammatory cytokines. We found that the migrated cells clearly demonstrate reversible loss of E-cadherin expression, which is consistent with subsequent vimentin expression alterations in comparison to control cells. Moreover, the data suggest that the AR mediated transcriptional program also contributes to mesenchymal-to-epithelial transition (MET) in prostate cancer progression. Furthermore, the quantitative proteomic analysis showed that migrated subpopulations from the same cell line presented different phenotypes in which the proteins overexpressed are involved in cell metabolism and RNA processing. According to KEGG pathway analysis, the ABC transporters were found to be the most significant. Thus, the dynamic process of cellular migration favors diverse genetic compositions under changing tumor microenvironments. The different levels of invasiveness are supported by shifting the cells in between these EMT and MET phenotypes.Article Citation - WoS: 8Citation - Scopus: 8Design and Performance Comparison of Polymer-Derived Ceramic Ambigels and Aerogels(American Chemical Society, 2023) Soraru, Gian Domenico; İçin, Öykü; Semerci, Tuğçe; Ahmetoğlu, Çekdar VakıfThis work reports the synthesis and characterization of preceramic-and polymer-derived SiOC aerogels obtained from a commercial siloxane resin. The preceramic aerogels were obtained by ambient pressure drying (ambigels) and CO2 supercritical drying. Despite different drying processes, the final ceramic ambi/aerogels have very similar microstructural features in density, porosity, pore size, and specific surface area. Both materials have shown promising results for oil sorption and water cleaning. Supercritically dried-SiOC aerogel had low thermal conductivity with 0.046 W.m(-1).K-1 at RT and 0.073 W.m(-1).K-1 at 500 degrees C. These results suggest that substituting the rather complicated and expensive CO2-SC drying with the more friendly and cheap ambient pressure drying can be done without having to accept significant microstructural/property degradation.Article Citation - WoS: 7Citation - Scopus: 7Investigating the Effects of Pa66 Electrospun Nanofibers Layered Within an Adhesive Composite Joint Fabricated Under Autoclave Curing(American Chemical Society, 2023) Esenoğlu, Gözde; Tanoğlu, Metin; Barışık, Murat; İplikçi, Hande; Yeke, Melisa; Nuhoğlu, Kaan; Türkdoğan, Ceren; Martin, Seçkin; Aktaş, Engin; Dehneliler, Serkan; Gürbüz, Ahmet Ayberk; İriş, Mehmet ErdemEnhancing the performance of adhesively joined composite components is crucial for various industrial applications. In this study, polyamide 66 (PA66) nanofibers produced by electrospinning were coated on unidirectional carbon/epoxy prepregs to increase the bond strength of the composites. Carbon/epoxy prepregs with/without PA66 nanofiber coating on the bonding region were fabricated using the autoclave, which is often used in the aerospace industry. The single lap shear Charpy impact energy and Mode-I fracture toughness tests were employed to examine the effects of PA66 nanofibers on the mechanical properties of the joint region. Scanning electron microscopy (SEM) was used to investigate the nanofiber morphology and fracture modes. The thermal characteristics of Polyamide 66 nanofibers were explored by using differential scanning calorimetry (DSC). We observed that the electrospun PA66 nanofiber coating on the prepreg surfaces substantially improves the joint strength. Results revealed that the single lap shear and Charpy impact strength values of the composite joint are increased by about 79 and 24%, respectively, by coating PA66 nanofibers onto the joining region. The results also showed that by coating PA66 nanofibers, the Mode-I fracture toughness value was improved by about 107% while the glass transition temperature remained constant.