Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Temporal Coherence of Single Photons Emitted by Hexagonal Boron Nitride Defects at Room Temperature(Amer Chemical Soc, 2026) Martinez-Pons, Juan Vidal; Kim, Sang Kyu; Behrens, Max; Izquierdo-Molina, Alejandro; Menendez Rua, Adolfo; Pacal, Serkan; Anton-Solanas, CarlosColor centers in hexagonal boron nitride (hBN) emerge as promising quantum light sources at room temperature, with potential applications in quantum communications, among others. The temporal coherence of emitted photons (i.e., their capacity to interfere and distribute photonic entanglement) is essential for many of these applications. Hence, it is crucial to study and determine the temporal coherence of this emission under different experimental conditions. In this work, we report the coherence time of the single photons emitted by an hBN defect in a nanocrystal at room temperature, measured via Michelson interferometry. The visibility of this interference vanishes when the temporal delay between the interferometer arms is a few hundred femtoseconds, highlighting that the phonon dephasing processes are 4 orders of magnitude faster than the spontaneous decay time of the emitter. We also analyze the single photon characteristics of the emission via correlation measurements, defect blinking dynamics, and its Debye-Waller factor. Our room temperature results highlight the presence of a strong electron-phonon coupling, suggesting the need to work at cryogenic temperatures to enable quantum photonic applications based on photon interference.Article Characterization and Energetic Property Evaluation of Novel Energetic Salts and Co-Crystals Formed with Nitropyrazoles and Pyridines(Amer Chemical Soc, 2025) Atceken, Nurunnisa; Bauer, Kaylyn M.; Nichol, Gary S.; Morrison, Carole A.; Pulham, Colin R.Nitropyrazoles are promising candidates to replace conventional explosives as they generally have positive heats of formation, good thermal stabilities, low friction and impact sensitivities and high energetic performance. In this study, 3,5-dinitropyrazole (DNP) and 3,4,5-trinitropyrazole (TNP) were combined with a series of pyridine derivatives to create nine new multicomponent crystals. Single-crystal X-ray diffraction shows that the herringbone-type packing observed in both DNP and TNP can be significantly altered to form puckered, wave-like and layered packing motifs. Differential scanning calorimetry and thermogravimetric analysis measurements show significant alteration in the thermal properties of the new materials, suggesting that the processing and energetic properties of DNP and TNP can be efficiently tuned through multicomponent crystallization. Preliminary impact sensitivity measurements performed on some of the materials also suggest that the mechanochemical responses of DNP and TNP can be altered through changing the crystal packing motifs. Overall, this study highlights the important role that multicomponent crystallization can play in tuning the structure/materials property relationships in energetic materials research.Article Protection of N-Type (Ni,Fe)TiSb Half-Heusler Materials Against Static and Cyclic Oxidation Using a Si-Doped Cr Coating(Amer Chemical Soc, 2025) Gurtaran, Mikdat; Zhang, Zhenxue; Li, Xiaoying; Dong, HanshanIn this study, Cr-Si coatings were deposited on N-type (Ni,Fe)TiSb thermoelectric (TE) materials by using a closed-field unbalanced magnetron sputtering PVD technique. Oxidation behavior was evaluated under both isothermal (static) conditions (500 degrees C for 10 h and 600 degrees C for 50 h) and thermal cycling regimens (500 and 600 degrees C for 10 or 50 1 h cycles). Mass gain, surface morphology, cross-sectional microstructure, elemental distribution, and phase composition were examined by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Regardless of exposure mode, uncoated samples oxidized severely: a duplex scale formed, consisting of an outer TiO2 layer and a subjacent NiSb-rich zone, accompanied by extensive cracking and delamination. In sharp contrast, the Cr-Si coatings remained thermally stable and highly oxidation-resistant, maintaining the substrate's integrity during both static and cyclic tests. After exposure, coated samples showed negligible mass gain, no discernible morphological change, and no mechanical damage, confirming that the Cr-Si layer markedly enhances thermal durability and prevents surface degradation.Article Molecular Engineering of Exchange Bias in Fe3GeTe2/Molecule Heterostructures(Amer Chemical Soc, 2025) Sharma, Mayank; Jo, Junhyeon; Avedissian, Garen; Bayindir, Bertug; Kang, Jun; Sahin, Hasan; Hueso, Luis E.Molecules offer a versatile route to tailor magnetism through chemical design and spin-state control. When integrated with surface-sensitive layered magnets, molecules can not only exhibit tunable magnetic properties or even activate distinct magnetic phases but can also interact with the layered magnets to manipulate their magnetic dynamics. Here, we demonstrate tunable exchange bias in hybrid heterostructures composed of the layered ferromagnet Fe3GeTe2 (FGT) and metallophthalocyanine (MPc) molecules having different central transition ions: MnPc, ZnPc, and H2Pc. The MnPc/FGT system exhibits a robust exchange bias of 1000 Oe at 10 K, with a record-high exchange bias-to-coercivity ratio of 0.37, attributed to the antiferromagnetic nature of MnPc. Surprisingly, the diamagnetic ZnPc induces a finite exchange bias of 200 Oe, highlighting the contribution of the emerging spinterface effect. In contrast, the metal-free H2Pc yields no exchange bias, underscoring the essential role of designed molecules for magnetic interaction. First-principles calculations reveal energetically favorable stacking configurations and spin alignments, in agreement with experimental observations. These results highlight the potential of molecular functionalization on magnetism, enabling the on-demand engineering of layered magnetic systems.Article Citation - WoS: 1Citation - Scopus: 1Electrochemical Sensors for Rapid Cardiovascular Disease Diagnostics(Amer Chemical Soc, 2025) Sanko, Vildan; Tekin, H. CumhurCardiovascular diseases (CVDs) remain a leading cause of death, particularly in developing countries, where their incidence continues to rise. Traditional CVD diagnostic methods are often time-consuming and inconvenient, necessitating more efficient alternatives. Rapid and accurate measurement of cardiac biomarkers released into body fluids is critical for early detection, timely intervention, and improved patient outcomes. Electrochemical methods offer a robust solution by enabling rapid, sensitive, selective, and multiplex detection of CVD biomarkers, paving the way for early diagnosis and treatment advancements. This review highlights the performance and potential of electrochemical sensors for detecting specific CVD biomarkers and related organic molecules. It explores electrochemical sensing mechanisms, their evolution, the integration of nanotechnology, and diverse sensing platforms. It also examines emerging technologies such as microfluidic, smartphone-integrated sensors, and microneedle- and tattoo-based sensors. Challenges and opportunities in integrating electrochemical sensors into point-of-care (POC) and wearable devices are discussed. Finally, the review compares commercial CVD sensors with existing methods and outlines future directions to advance the field.Article Enabling Fluorescence Lifetime Imaging Multiplexing Using UnaG Through Its Modification With Canonical and Noncanonical Amino Acids(Amer Chemical Soc, 2025) Terekhova, Valentina V.; Bodunova, Daria V.; Gorokhov, Egor S.; Tsoraev, Georgy V.; Sidorenko, Svetlana V.; Vasilev, Ruslan A.; Kirpichnikov, Mikhail P.Fluorogen-activating proteins are powerful molecular tools for microscopy, including functional imaging. These proteins serve as an alternative to GFP-like proteins, as they do not require oxygen for chromophore maturation. However, the restricted selectivity of proteins to chromophores, combined with the limited number of spectral channels of conventional fluorescent microscopes, hinders the development of multicolor synthetic dyes. Additionally, the poor cell and tissue permeability of synthetic chromophores further limits their utility. In this work, we address these challenges by combining time-resolved methods with the rational design of the UnaG protein, which utilizes bilirubin as a natural chromophore. To turn UnaG into a palette of probes for fluorescence lifetime imaging microscopy (FLIM), we solved two practical problems: first, we determined the limits of bilirubin lifetime variations in response to changes in the protein structure and, second, we determined what minimal structural changes can be reliably distinguished by lifetime analysis in cellula. Combining classical point mutagenesis and the translational introduction of noncanonical amino acids, we generated UnaG with fluorescence lifetimes ranging from hundreds of picoseconds to nanoseconds. We explored the potential for further modification of the UnaG protein matrix to optimize spectral and temporal characteristics of bilirubin fluorescence and its quantitative detection through time-resolved approaches.Article Fabrication of Flexible Nanoporous Platinum Films Via One-Pot Liquid Crystal Templated Synthesis(Amer Chemical Soc, 2025) Demir, Seren; Polat, Pelin; Tertemiz, Necip Ayhan; Vural, Beyza; Babahan, Elian Melissa; Orhan, Ozan Baran; Balci, Fadime MertNanoporous platinum (NPP) thin films are crucial for applications in electrocatalysis, fuel cells, nanophotonics, and gas sensing. Conventional fabrication methods, such as dealloying, often leave residual elements that degrade the performance of the NPP thin films in applications such as electrocatalysis. In this study, for the first time, we introduce a novel method to fabricate ultrapure, flexible, large-area NPP thin films through a one-pot, liquid crystal-templated synthesis. A hexagonal lyotropic liquid crystal (LLC) phase, composed of a strong acid, a nonionic surfactant, water, and hexachloroplatinic acid, serves as a template. The LLC films, prepared with hexachloroplatinic acid concentrations of 0.1-0.5 M, exhibit distinct optical textures under a polarizing optical microscope and display low-angle diffraction patterns when analyzed with an X-ray diffractometer. Calcination at 450 degrees C yields ultrapure, conductive, and black colored NPP films. Importantly, we fabricate freestanding NPP thin films and successfully transfer them onto both rigid and flexible substrates. Bending tests reveal that a four-layer flexible NPP film having a thickness of around similar to 174 nm maintains a stable sheet resistance (similar to 30 ohm/sq) after several hundred bend cycles (1000 cycles). These findings highlight the potential of ultrapure NPP films with high nanopore and ligament density for applications in electrocatalysis, fuel cells, gas sensors, broadband absorbers, bioelectronics, and flexible electronics.Article Durable ZrB2–ZrC Composite Materials as Advanced Electrodes for High-Performance Supercapacitors(Amer Chemical Soc, 2025) Paksoy, Aybike; Gungor, Ahmet; Yildirim, Ipek Deniz; Arabi, Seyedehnegar; Erdem, Emre; Balci-Cagiran, OzgeBoride and carbide-based materials attract increasing attention as promising options for energy storage applications. This research focuses on synthesizing pure boride and carbide compounds of zirconium (ZrB2 and ZrC) and their composite powders using mechanical activation-assisted route and subsequent heating processes. The chemical and microstructural characterization results indicate that the synthesized composite powders are of high purity, possess submicron-scale particle sizes (below 400 nm), and exhibit a high surface area of up to 9.41 m2/g. Supercapacitor devices, using the resulting powders as symmetrical electrodes, exhibit high energy density values ranging from 5.8 to 8.8 Wh/kg. The ZrB2-15 wt % ZrC composite sample achieves the highest power density at 155 W/kg, compared to 118 W/kg for the pure ZrB2 sample. Cycling tests demonstrate exceptional capacitance retention (99.4-99.9%) and cyclic stability, even after 5000 cycles, highlighting the high durability of the composite samples. These findings show that ZrB2-ZrC composites exhibit high energy and power density values and excellent cycling performance, making them strong candidates for use in high-performance supercapacitor devices.Article Citation - WoS: 2Citation - Scopus: 2Modulating Cancer Stem Cell Characteristics in CD133+ Melanoma Cells through Hif1α, KLF4, and SHH Silencing(Amer Chemical Soc, 2025) Ozdil, Berrin; Güler, Günnur; Avci, Cigir Biray; Calik-Kocaturk, Duygu; Gorgulu, Volkan; Uysal, Aysegul; Guler, Gunnur; Aktug, HuseyinMalignant melanoma is a highly aggressive form of skin cancer, partly driven by a subset of cancer stem cells (CSCs) with remarkable capacities for self-renewal, differentiation, and resistance to therapy. In this study, we examined how silencing three key genes-Hif1 alpha, KLF4, and SHH-affects CSC characteristics. Using small interfering RNA (siRNA)-based approaches, we observed significant changes at both the gene and protein levels, shedding light on how these pathways influence melanoma progression. Our results demonstrated that silencing these genes reduces the stem-like features of CSCs. Notably, Hif1 alpha silencing triggered a marked decrease in hypoxia-related gene expression, while targeting SHH led to a reduction in Gli1, a downstream effector of SHH signaling, highlighting its potential as a therapeutic target. We also observed changes in epigenetic markers such as HDAC9 and EP300, which play crucial roles in maintaining stemness and regulating gene expression. Interestingly, these interventions appeared to reprogram CSCs, pushing them toward a phenotype distinct from both traditional CSCs and non-stem cancer cells (NCSCs). Our findings emphasize the importance of targeting key signaling pathways in melanoma CSCs and underscore the value of mimicking the tumor microenvironment in experimental models. By revealing the dynamic plasticity of melanoma CSCs, this study offers fresh insights into potential therapeutic strategies, particularly using siRNA to modulate pathways associated with tumor progression and stem cell behavior.Article Citation - WoS: 2Citation - Scopus: 2Integration of Leu-Asp Cell Attachment Motif Into Self-Assembling Peptide Sequences for Nanofibrillar Hydrogel Formation in Wound Healing(Amer Chemical Soc, 2025) Tarim, Burcu Sirma; Sırma Tarım, Burcu; Tamburaci, Sedef; Top, Ayben; Uysal, Berk; Top, AybenFunctionalizing peptide sequences with cell adhesion motifs enhances their cellular bioactivity. Numerous studies have focused on incorporating the Arg-Gly-Asp (RGD) motif into peptide hydrogels; however, the integration of other bioactive domains has yet to be comprehensively investigated. In this study, one of the essential fibronectin-derived cell-binding domains, Leu-Asp-Val (LDV), was integrated into the self-assembling peptide to obtain extracellular matrix (ECM)-mimetic nanofibrillar hydrogelators. IBP1A (NH2-KLDVKLDVKLKV-CONH2) and IBP1B (NH2-KLDVKLDVKLDV-CONH2) peptides were designed accordingly. These peptides self-assemble into hydrogels in phosphate-buffered saline (PBS) at pH 7.4 and deionized water at neutral pH with storage modulus values between similar to 200 and similar to 2000 Pa. Flow curves and the cyclic strain sweep data confirmed that the hydrogels have shear thinning, injectability, and self-healing properties. Flexible nanofibrillar morphology was observed in the TEM images. Nanofibril widths of IBP1A and IBP1B networks were measured as 8.2 +/- 1.1 and 4.5 +/- 0.8 nm, respectively. In vitro tests were also conducted to evaluate these peptides in wound healing applications. The IBP1A peptide with a +3 charge at neutral pH exhibited modest antibacterial activity against Gram (+) and Gram (-) bacteria. In vitro cell culture experiments show that the IBP1A and IBP1B hydrogels promoted the growth of fibroblast cells and glycosaminoglycan secretion compared with the KLDL12 control peptide, which does not contain the LDV motif. The designed hydrogels induced cell attachment within 72 h by altering the cell morphology similar to their natural 3D microenvironment, whereas cells exhibited spindle-like morphology on the KLDL12 hydrogel and tissue culture polystyrene (TCP). Moreover, IBP1B accelerated in vitro wound healing by facilitating fibroblast migration. These results suggest that these bioactive injectable peptide hydrogels have potential in wound healing and skin tissue regeneration.