PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7645

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  • Article
    Dimensionality Effects in Anisotropic Single Layers TiSe5 and TiTe5: a Comparative Study of 2D Sheets and 1D Nanochains
    (IOP Publishing Ltd, 2026) Can Dogan, Kadir; Kutay Tamdogan, Omer; Bozkurt, Yagmur; Cetin, Zebih; Yagmurcukardes, Mehmet
    In this study, we present a comprehensive first-principles investigation of the structural, vibrational, and electronic properties of titanium pentachalcogenide structures in both two-dimensional (2D) and one-dimensional (1D) nanochain (NC) forms. Total energy and geometry optimizations reveal that the 2D TiX5 (X = Se, Te) structures exhibit in-plane anisotropy arising from the trigonal prismatic TiX3 units interconnected via the chalcogenide chains. Phonon band dispersions and elastic tensor elements confirm the dynamical and mechanical stability of the 2D layers, respectively. Electronically, while TiTe5 is a metal, TiSe5 possesses direct band gap semiconducting behavior. In addition, free-standing 1D NC counterparts, which are sub-units of the 2D structures, are investigated by means of their stability. Three stable 1D NCs, namely TiTe5-NC, TiSe7-NC, and TiTe7-NC, are found to be composed of edge-sharing TiX6-like units with either five- or seven-fold coordination. The dynamically stable 1D NCs are shown to be semiconductors with relatively larger band gaps as compared to 2D layers. Predicted Raman spectra reveal clear signatures of vibrational mode evaluations as a result of quantum confinement from the 2D layer to the 1D NC. Moreover, finite-temperature ab-initio quantum molecular dynamics simulations at 300 K confirm the thermal stability of both the 2D TiX5 layers and 1D NC derivatives, showing that the Ti-based systems retain their structural integrity under ambient conditions and are feasible candidates for experimental synthesis. Our findings highlight the formation of stable semiconducting 1D NCs of Ti-pentachalcogenides from their 2D counterparts.
  • Article
    Developing Gold Nanoparticles Decorated With Carbon-Dots for Multiplexed Cellular Imaging
    (IOP Publishing Ltd, 2025) Kavuranpala, Tugce; Saydullaeva, Iroda; Ozcelik, Serdar
    This study focuses on developing a novel hybrid nanomaterial composed of gold nanoparticle decorated with carbon dots, termed AuNP@C-dot, as a versatile platform for multiplexed imaging. Structural and spectral characterizations confirmed the successful conjugation of C-dots to AuNPs via covalent bonding, as evidenced by FTIR, X-ray photoelectron spectra, HRTEM analyses, and UV-Vis and fluorescence spectroscopies. The fluorescence intensities of C-dots are doubled through the conjugation to the AuNPs. The conjugation of fluorescent C-dots to plasmon-resonant AuNPs enables simultaneous multicellular imaging by taking advantage of the fluorescent signaling of C-dots and the scattering signaling of AuNPs. In vitro studies using human lung cell lines (A549 and BEAS-2B) confirmed the multiplexed imaging and revealed efficient cellular uptake and subcellular localization of AuNP@C-dots, including nuclear translocation, which is critical for radiotherapy and photodynamic therapy. Cell viability assessments utilizing a colorimetric assay for measuring cell metabolic activity and a colony formation assay demonstrated good biocompatibility of AuNP@C-dots at relevant concentrations. It can be envisioned that the AuNP@C-dot hybrid system may improve the detection and monitoring of cell health and disease due to its dual-modal imaging capability. Furthermore, they could be used for supervising controlled release of therapeutic agents, tailored for enhanced treatment efficacy. This study demonstrates the potential of C-dot-conjugated AuNPs as a multifunctional tool with inherent control mechanisms for the next-generation cellular analysis, drug administration, and diagnostic strategies.