Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 3Citation - Scopus: 3Reusable polymer-based fluorescent sensor nanoprobe for selective detection of cd<sup>2+</sup> ions in real water sources(Royal Society of Chemistry, 2024) Karabıyık, Merve; Ebil, ÖzgençCadmium, which is classified as a highly toxic metal among all heavy metals, poses a threat to the environment and human health, even at trace levels. In this study, for the first time in the literature, a fluorescent sensor nanoprobe that can selectively detect Cd2+ ions in different real water sources has been developed by attaching a CdTe QD-4 amino TEMPO complex to an iCVD deposited cross-linked copolymer surface with high mechanical strength. Under the appropriate conditions such as pH, concentration, type of solvent and reaction time, the interaction between Cd2+ ions and the polymer-based QD-4AT nanoprobe was enhanced, and the detection of this target ion with high selectivity was made possible even in the environments with complex structures containing different heavy metal ions. The limit of detection (LOD) of Cd2+ ions with this proposed polymer sensor nanoprobe was found to be 0.195 mu M by using the linear detection region of 0.0784-2.5 mu M (R-2 > 0.997). In the literature, several sensor probes have been developed for the detection of Cd2+ ions and have only been investigated for single use in liquid media. The polymer sensor nanoprobe developed in this study has high sensitivity and selectivity in terms of detection limit compared to the previous ones, and the results obtained from the multiple use studies indicate that this nanoprobe can be used more than once for ion detection without loss of performance. This is a brand-new product for fluorescence sensing studies and will be a great source of inspiration for them.Article Citation - WoS: 8Citation - Scopus: 9Development of Plant-Based Biopolymer Coatings for 3d Cell Culture: Boron-Silica Quince Seed Mucilage Nanocomposites(Royal Society of Chemistry, 2023) Yılmaz, Hilal Deniz; Cengiz, Uğur; Derkuş, Burak; Arslan, Yavuz EmreSpheroid formation with spontaneous aggregation has captured interest in most cell culture studies due to its easy set-up and more reliable results. However, the economic and technical costs of the advanced systems and commercial ultra-low adhesive platforms have pushed researchers into pursuing alternatives. Nowadays, polymeric coatings, including poly-hydroxyethyl methacrylate and agar/agarose, are the commonly used polymers for non-adhesive plate fabrication, yet the costs and working solvent or heat-dependent preparation procedures maintain the need for the development of novel biomaterials. Here, we propose a greener and more economical approach for producing non-adherent surfaces and spheroid formation. For this, a plant waste-based biopolymer from quince fruit (Cydonia oblonga Miller, from Rosaceae family) seeds and boron-silica precursors were introduced. The unique water-holding capacity of quince seed mucilage (Q) was enriched with silanol and borate groups to form bioactive and hydrophilic nanocomposite overlays for spheroid studies. Moreover, 3D gel plates from the nanocomposite material were fabricated and tested in vitro as a proof-of-concept. The surface properties of coatings and the biochemical and mechanical properties of the nanocomposite materials were evaluated in-depth with techniques, and extra hydrophilic coatings were obtained. Three different cell lines were cultured on these nanocomposite surfaces, and spheroid formation with increased cellular viability was recorded on day 3 with a >200 & mu;m spheroid size. Overall, Q-based nanocomposites are believed to be a fantastic alternative for non-adherent surface fabrication due to their low-cost, easy operation, and intrinsic hydration layer forming capacity with biocompatible nature in vitro.Article Citation - WoS: 1Citation - Scopus: 1A Multi-Layered Graphene Based Gas Sensor Platform for Discrimination of Volatile Organic Compounds Via Differential Intercalation(Royal Society of Chemistry, 2023) Özkendir İnanç, Dilce; Ng, Zhi Kai; Başkurt, Mehmet; Keleş, Berfin; Vardar, Gökay; Şahin, Hasan; Tsang, Siu Hon; Palaniappan, Alagappan; Yıldız, Ümit Hakan; Teo, EhtSelective and sensitive detection of volatile organic compounds (VOCs) is of critical importance for environmental monitoring, disease diagnosis and industrial applications. Among VOCs, assay development for primary alcohols has captured significant research attention since their toxicity causes adverse effects on gastrointestinal and central nerve systems, resulting in irreversible blindness, and coma, and can be even fatal at high exposure levels. However, selective detection of primary alcohols is extremely challenging owing to the similarity in their molecular structure and characteristic groups. Herein, we have attempted to investigate the differential methanol (MeOH)-ethanol (EtOH) discriminative properties of single-layer, bi-layer, and multi-layer graphene morphologies. Chemiresistors fabricated using the three morphologies of graphene illustrate discriminative MeOH-EtOH responses, which is attributed to the phenomenon of differential intercalation of MeOH within layered graphene morphologies as compared to that of EtOH. This hypothesis is verified by density functional theory calculations, which revealed that the adsorption of EtOH molecules on the graphene surface is more energetically favorable as compared to that of MeOH molecules, thereby inhibiting their intercalation within the layered graphene morphologies. It is further evaluated that the degree of MeOH intercalation increases with increasing layers of graphene for obtaining differential MeOH-EtOH responses. Experimental results suggest possibilities to develop selective and sensitive MeOH assays fabricated using various graphene morphologies in a combinatorial sensor array format.Article Citation - WoS: 6Citation - Scopus: 6Polar Solvent-Free Room Temperature Synthesis of Cspbx3 (x = Br, Cl) Perovskite Nanocubes(Royal Society of Chemistry, 2023) Güvenç, Çetin Meriç; Kocabaş, Aşkın; Balcı, SinanConventionally, colloidal lead halide perovskite nanocubes have been synthesized by the hot-injection or ligand-assisted reprecipitation (LARP) methods. We herein demonstrate a polar solvent-free room temperature method for the synthesis of CsPbX3 (X = Br, Cl) nanocubes. In addition to the commonly used ligand pair of oleylamine and oleic acid, guanidinium (GA) has been used to passivate the surface of the nanocrystals. Our study demonstrates that GA inhibits the formation of low dimensional structures such as nanowires and nanoplatelets and further supports the formation of perovskite nanocubes. In fact, GA diminishes the restricted monomer-addition effect of long-chain oleylammonium (OLAM) ions to the nanocrystal. We show that above a critical GA/OLAM molar ratio, the synthesis yields homogeneous CsPbX3 (X = Br, Cl) nanocubes. Importantly, we observe the nucleation and growth kinetics of the GA-assisted CsPbBr3 nanocube formation by using in situ absorption and photoluminescence (PL) measurements. Small nanocrystals with an excitonic absorption peak at around 435 nm and photoluminescence (PL) maxima at 447 nm were nucleated and continuously shifted to longer wavelengths during the growth period. Crucially, our method allows the synthesis of CsPbCl3 nanocubes at room temperature without using polar organic solvents. The synthesized CsPbBr3, CsPb(Cl0.5Br0.5)3, and CsPbCl3 nanocubes have PL peaks at 508 nm, 443 nm, and 405 nm, photoluminescence quantum yields (PLQY) of 85%, 58% and 5%, and lifetimes of 18.98 ns, 18.97 ns, and 14.74 ns, respectively.Article Citation - WoS: 2Citation - Scopus: 2Size Driven Barrier To Chirality Reversal in Electric Control of Magnetic Vortices in Ferromagnetic Nanodiscs(Royal Society of Chemistry, 2022) Aldulaimi, W. A. S.; Okatan, Mahmut Barış; Şendur, Kürşat; Onbaşlı, Mehmet Cengiz; Mısırlıoğlu, İbrahim BurçNew high density storage media and spintronic devices come about with a progressing demand for the miniaturization of ferromagnetic structures. Vortex ordering of magnetic dipoles in such structures has been repeatedly observed as a stable state, offering the possibility of chirality in these states as a means to store information at high density. Electric pulses and magnetoelectric coupling are attractive options to control the chirality of such states in a deterministic manner. Here, we demonstrate the chirality reversal of vortex states in ferromagnetic nanodiscs via pulsed electric fields using a micromagnetic approach and focus on the analysis of the energetics of the reversal process. A strong thickness dependence of the chirality reversal in the nanodiscs is found that emanates from the anisotropy of the demagnetizing fields. Our results indicate that chiral switching of the magnetic moments in thin discs can give rise to a transient vortex-antivortex lattice not observed in thicker discs. This difference in the chirality reversal mechanism emanates from profoundly different energy barriers to overcome in thin and thicker discs. We also report the polarity-chirality correlation of a vortex that appears to depend on the aspect ratio of the nanodiscs.Article Citation - WoS: 17Citation - Scopus: 18Development of a Hydrocolloid Bio-Ink for 3d Bioprinting(Royal Society of Chemistry, 2022) Yıldırım, Özüm; Arslan Yıldız, AhuA new generation of bio-inks that are soft, viscous enough, stable in cell culture, and printable at low printing pressures is required in the current state of 3D bioprinting technology. Hydrogels can meet these features and can mimic the microenvironment of soft tissues easily. Hydrocolloids are a group of hydrogels which have a suitable gelling capacity and rheological properties. According to the literature, polysaccharide-based hydrocolloids are used in the food industry, wound healing technologies, and tissue engineering. Quince seed hydrocolloids (QSHs), which consist of mostly glucuronoxylan, can easily be obtained from quince seeds by water extraction. In this study, the use of a QSH as a bio-ink was investigated. The suitability of QSH for the printing process was assessed by rheological, uniformity and pore factor analyses. Appropriate printing parameters were determined and the characterization of the bioprinted QSHs was performed by SEM analysis, water uptake capacity measurement, and protein adsorption assay. The bioprinted QSHs had excellent water uptake capacity and showed suitable protein adsorption behaviour. Analyses of the biocompatibility and cellular viability of bioprinted QSHs were conducted using NIH-3T3 fibroblast cells and the results were found to be high during short and long-term cell culture periods. It was proved that QSH is a highly promising bio-ink for 3D bioprinting and further tissue engineering applications.Article Citation - WoS: 2Citation - Scopus: 2Magnetic Single-Layer Nanoribbons of Manganese Oxide: Edge- and Width-Dependent Electronic Properties(Royal Society of Chemistry, 2022) Sözen, Yiğit; Topkıran, Uğur; Şahin, HasanIn the present work, the structural, magnetic, and electronic properties of the two- and one-dimensional honeycomb structures of recently synthesized MnO [Zhang et al., Hexagonal metal oxide monolayers derived from the metal-gas interface, Nat. Mater., 2021, 20, 1073-1078] are investigated by using first-principles calculations. Our calculations show that the single-layer 2D MnO crystal has a degenerate antiferromagnetic (AFM) ground state and a relatively less favorable ferromagnetic (FM) state. In addition, the magnetic anisotropy calculations unveil that the easy-axis direction for magnetism originating from unpaired electron states in manganese atoms is normal to the crystal plane. Electronically, while the FM MnO is a direct semiconductor with a narrow bandgap, AFM phases display large indirect bandgap semiconducting behavior. Moreover, the calculations on nanoribbons of MnO reveal that zigzag-edged ribbons display metallic behaviors, whereas armchair-edged nanoribbons are semiconductors. Magnetically, for both zigzag- or armchair-edged nanoribbons, the AFM order perpendicular to the nanoribbon growth direction is found to be favorable over the other AFM and FM orders. Moreover, depending on the edge symmetry and ribbon width, forbidden bandgap values of nanoribbons display distinct family behaviors.Article Citation - WoS: 6Citation - Scopus: 7Interface-Dependent Phononic and Optical Properties of Geo/Moso Heterostructures(Royal Society of Chemistry, 2022) Yağmurcukardeş, Mehmet; Sözen, Yiğit; Başkurt, Mehmet; Peeters, François M.; Şahin, HasanThe interface-dependent electronic, vibrational, piezoelectric, and optical properties of van der Waals heterobilayers, formed by buckled GeO (b-GeO) and Janus MoSO structures, are investigated by means of first-principles calculations. The electronic band dispersions show that O/Ge and S/O interface formations result in a type-II band alignment with direct and indirect band gaps, respectively. In contrast, O/O and S/Ge interfaces give rise to the formation of a type-I band alignment with an indirect band gap. By considering the Bethe-Salpeter equation (BSE) on top of G0W0 approximation, it is shown that different interfaces can be distinguished from each other by means of the optical absorption spectra as a consequence of the band alignments. Additionally, the low-and high-frequency regimes of the Raman spectra are also different for each interface type. The alignment of the individual dipoles, which is interface-dependent, either weakens or strengthens the net dipole of the heterobilayers and results in tunable piezoelectric coefficients. The results indicate that the possible heterobilayers of b-GeO/MoSO asymmetric structures possess various electronic, optical, and piezoelectric properties arising from the different interface formations and can be distinguished by means of various spectroscopic techniques.Article Citation - WoS: 13Citation - Scopus: 14Synthesizing and Evaluating the Photodynamic Efficacy of Asymmetric Heteroleptic A(7)b Type Novel Lanthanide Bis-Phthalocyanine Complexes(Royal Society of Chemistry, 2021) Önal, Emel; Tüncel, Özge; Albakour, Mohamad; Gümüşgöz Çelik, Gizem; Gül Gürek, Ayşe; Özçelik, SerdarIn this study heteroleptic A(7)B type novel Lu(iii) and Eu(iii) lanthanide phthalocyanines (LnPc(Pox)[Pc '(AB(3)SH)]) with high extinction coefficients have been synthesized as candidate photosensitizers with reaction yields higher than 33%. The singlet oxygen quantum yields of LuPc(Pox)[Pc '(AB(3)SH)] and EuPc(Pox)[Pc '(AB(3)SH)], respectively, were measured 17% and 1.4% by the direct method in THF. The singlet oxygen quantum yield of LuPc(Pox)[Pc '(AB(3)SH)] in THF is the highest among lutetium(iii) bis-phthalocyanine complexes to date. The photodynamic efficacy of the heteroleptic lanthanide phthalocyanines was evaluated by measuring cell viabilities of A549 and BEAS-2B lung cells, selected to representing in vitro models for testing cancer and normal cells against potential drugs. The cell viabilities demonstrated concentration dependent behavior and were varied by the type of phthalocyanines complexes. Irradiation of the cells for 30 minutes with LED array at 660 nm producing flux of 0.036 J cm(-2) s(-1) increased cell death for LuPcPox-OAc, LuPc(Pox)[Pc '(AB(3)SH)] and ZnPc. The IC50 concentrations of LuPc(Pox)[Pc '(AB(3)SH)] and ZnPc were determined to be below 10 nM for both cell lines, agreeing very well with the singlet oxygen quantum yield measurements. These findings suggest that LuPc(Pox)[Pc '(AB(3)SH)] and particularly LuPcPox-OAc are promising drug candidates enabling lowered dose and shorter irradiation time for photodynamic therapy.Article Citation - WoS: 34Citation - Scopus: 34Decellularised Extracellular Matrix Decorated Pcl Polyhipe Scaffolds for Enhanced Cellular Activity, Integration and Angiogenesis(Royal Society of Chemistry, 2021) Dikici, Serkan; Aldemir Dikici, Betül; MacNeil, Sheila; Claeyssens, FrederikWound healing involves a complex series of events where cell-cell and cell-extracellular matrix (ECM) interactions play a key role. Wounding can be simple, such as the loss of the epithelial integrity, or deeper and more complex, reaching to subcutaneous tissues, including blood vessels, muscles and nerves. Rapid neovascularisation of the wounded area is crucial for wound healing as it has a key role in supplying oxygen and nutrients during the highly demanding proliferative phase and transmigration of inflammatory cells to the wound area. One approach to circumvent delayed neovascularisation is the exogenous use of pro-angiogenic factors, which is expensive, highly dose-dependent, and the delivery of them requires a very well-controlled system to avoid leaky, highly permeable and haemorrhagic blood vessel formation. In this study, we decorated polycaprolactone (PCL)-based polymerised high internal phase emulsion (PolyHIPE) scaffolds with fibroblast-derived ECM to assess fibroblast, endothelial cell and keratinocyte activity in vitro and angiogenesis in ex ovo chick chorioallantoic membrane (CAM) assays. Our results showed that the inclusion of ECM in the scaffolds increased the metabolic activity of three types of cells that play a key role in wound healing and stimulated angiogenesis in ex ovo CAM assays over 7 days. Herein, we demonstrated that fibroblast-ECM functionalised PCL PolyHIPE scaffolds appear to have great potential to be used as an active wound dressing to promote angiogenesis and wound healing.