Photonics / Fotonik
Permanent URI for this collectionhttps://hdl.handle.net/11147/2590
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Book Part Citation - Scopus: 3Advances and Future Perspective of Graphene Field Effect Transistors (gfets) for Medical Diagnostics and Point-Of Tools(World Scientific Publishing, 2022) İnanç, Dilce; Mutlu, Mustafa Umut; Karabacak, Soner; Yıldız, Ümit HakanRecently, major focus has been centered to enhance the capability of graphenebased devices and to facilitate utilization of graphene for biological applications by lowering its toxicity. In this chapter, from synthesis to applications, many of the conspicuous characteristics of graphene have been elaborately reviewed. We primarily focused on graphene-based field effect transistor (FET) for medical diagnostics and point-of-care applications. The device configurations and their application potential as well as sensing capability of various graphene FETs (GFETs) have been discussed. Here, we have also presented several aspects and advantages of GFETs in medical applications while discussing their pros and cons in commercialization. We address the advances and challenges for GFET-based sensing platforms for the medical applications and elaborate the combination strategy of GFETs with the existing commercial systems. © 2023 by World Scientific Publishing Co. Pte. Ltd.Article Citation - Scopus: 1A Perspective on the State-Of Functionalized 2d Materials(American Institute of Physics, 2023) Duran, Tuna; Yayak, Yankı Öncü; Aydın, Hasan; Peeters, François M.; Yağmurcukardeş, MehmetTwo-dimensional (2D) ultra-thin materials are more crucial than their bulk counterparts for the covalent functionalization of their surface owing to atomic thinness, large surface-to-volume ratio, and high reactivity of surface atoms having unoccupied orbitals. Since the surface of a 2D material is composed of atoms having unoccupied orbitals, covalent functionalization enables one to improve or precisely modify the properties of the ultra-thin materials. Chemical functionalization of 2D materials not only modifies their intrinsic properties but also makes them adapted for nanotechnology applications. Such engineered materials have been used in many different applications with their improved properties. In the present Perspective, we begin with a brief history of functionalization followed by the introduction of functionalized 2D materials. Our Perspective is composed of the following sections: the applications areas of 2D graphene and graphene oxide crystals, transition metal dichalcogenides, and in-plane anisotropic black phosphorus, all of which have been widely used in different nanotechnology applications. Finally, our Perspectives on the future directions of applications of functionalized 2D materials are given. The present Perspective sheds light on the current progress in nanotechnological applications of engineered 2D materials through surface functionalization. © 2023 Author(s).Article Citation - WoS: 5Citation - Scopus: 4Polarity Induced Vapochromism and Vapoluminescence of Polythiophene Derivatives for Volatile Organic Compounds Classification(Elsevier, 2023) Karabacak, Soner; Qun, David Lee Chao; Ammanath, Gopal; Yeasmin, Sanjida; Yağmurcukardeş, Mehmet; Palaniappan, Alagappan; Liedberg, Bo; Yıldız, Ümit HakanPolarity induced vapochromic and vapoluminescent properties of cationic poly-3-alkoxythiophene derivatives (PT) casted on polyvinylidene fluoride (PVDF) membranes are reported. PT with six different pendant groups are designed to differentially interact with volatile organic compounds (VOC) of varying polarities, thereby enabling their classification. PT exhibit a rapid vapochromic response with a concurrent modulation of vapoluminescence due to the non-covalent cation-? interactions between the pendant groups and the PT backbone. Adsorption of VOC on pendant groups alters the conformation of PT backbone, thus resulting in an increase in intensity and blue shifting of fluorescence emission within the visible spectrum. The vapoluminescent responses are found to be more sensitive with a limit of detection (LOD) of ?7 ppm and a wider dynamic range as compared to the vapochromic responses with a LOD of ?60 ppm for the detection of a model VOC: chloroform. Notably, all the PT illustrate an instantaneous recovery of colour and luminescence upon desorption of VOC. PT interaction with VOC of varying polarities was ascertained using density functional theory (DFT) and principal component analysis (PCA) methodologies. In summary, the polarity induced vapochromic and vapoluminescent properties of PT could yield a selective and sensitive vapochromic and fluorometric dual-mode VOC detection platform. © 2023Article 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: 49Citation - Scopus: 54Highly Porous Poly(o-Phenylenediamine) Loaded Magnetic Carboxymethyl Cellulose Hybrid Beads for Removal of Two Model Textile Dyes(Springer, 2022) Arıca, Tuğçe Aybüke; Balcı, Fadime Mert; Balcı, Sinan; Arıca, Mehmet YakupEnsuring the removal of complex dyes from wastewater is a topic of great interest as it is vital for the environment. The present study reports a facile preparation method for poly(o-phenylenediamine) [p(o-PDA)] micro-particles loaded to magnetic carboxymethyl cellulose (CMC) hydrogel beads as adsorbents. The prepared products were characterized by FTIR, TGA, VSM, SEM, BET, and zeta sizer. The Fe3O4@p(o-PDA)@CMC beads were used for the removal of Reactive Blue 4 (RB-4) and Congo Red (CR) textile dyes from an aqueous medium. Different factors, such as adsorbent dose, initial pH, ionic strength, contact time, temperatures, and initial RB-4 and CR concentrations were examined. The maximum adsorption capacities of the RB-4 dye and CR at optimum pH 5 reached 398.7 and 524.6 mg/g in 120 min, respectively. The adsorption of RB-4 and CR on the hybrid magnetic beads can be due to the electrostatic, hydrogen bonding, and π-π interactions. Moreover, the magnetic hybrid beads showed easy regeneration ability and good reusability. The adsorbent can be a very good candidate for the efficient removal of micro-pollutant from wastewater.Article Citation - WoS: 4Citation - Scopus: 4Identification of a Magnetic Phase Via a Raman Spectrum in Single-Layer Mnse: an Ab Initio Study(Elsevier, 2022) Yayak, Yankı Öncü; Şahin, Hasan; Yağmurcukardeş, MehmetMotivated by the recent experimental realization of single-layer two-dimensional MnSe [ACS Nano2021, 15, 13794-13802], structural, magnetic, elastic, vibrational, and electronic properties of single-layer MnSe are investigated by using density functional theory-based calculations. Among four different magnetic phases, namely, ferromagnetic (FM) and Nẽel-, zigzag-, and stripy-antiferromagnetic (AFM) phases, the Nẽel-AFM structure is found to be the energetically most favorable phase. Structural optimizations show the formation of in-plane anisotropy within the structures of zigzag- and stripy-AFM phases in single-layer MnSe. For the dynamically stable four magnetic phases, predicted Raman spectra reveal that each phase exhibits distinctive vibrational features and can be distinguished from each other. In addition, the elastic constants indicate the mechanical stability of each magnetic phase in single-layer MnSe and reveal the soft nature of each phase. Moreover, electronic band dispersion calculations show the indirect band gap semiconducting nature with varying electronic band gap energies for all magnetic phases. Furthermore, the atomic orbital-based density of states reveals the existence of out-of-plane orbitals dominating the top valence states in zigzag- and stripy-AFM phases, giving rise to the localized states. The stability of different magnetic phases and their distinct vibrational and electronic properties make single-layer MnSe a promising candidate for nanoelectronic and spintronic applications.Article Citation - WoS: 17Citation - Scopus: 19Strong Coupling of Carbon Quantum Dots in Liquid Crystals(American Chemical Society, 2022) Sarısözen, Sema; Polat, Nahit; Mert Balcı, Fadime; Güvenç, Çetin Meriç; Kocabaş, Çoşkun; Yağlıoğlu, Halime Gül; Balcı, SinanCarbon quantum dots (CDs) have recently received a tremendous amount of interest owing to their attractive optical properties. However, CDs have broad absorption and emission spectra limiting their application ranges. We herein, for the first time, show synthesis of water-soluble red emissive CDs with a very narrow line width (∼75 meV) spectral absorbance and hence demonstrate strong coupling of CDs and plasmon polaritons in liquid crystalline mesophases. The excited state dynamics of CDs has been studied by ultrafast transient absorption spectroscopy, and CDs display very stable and strong photoluminescence emission with a quantum yield of 35.4% and a lifetime of ∼2 ns. More importantly, we compare J-aggregate dyes with CDs in terms of their absorption line width, photostability, and ability to do strong coupling, and we conclude that highly fluorescent CDs have a bright future in the mixed light-matter states for emerging applications in future quantum technologies.Article Citation - WoS: 4Citation - Scopus: 3Hg(ii)-Mediated Intramolecular Cyclization of Alkynyl Hydrazones: Towards a New Reaction-Based Sensing Approach for Hg(ii) Ions(Wiley, 2022) Tütüncü, Büşra Buse; Cebeci, Miray; Emrullahoğlu, MustafaDrawing upon an intramolecular cyclization/annulation reaction sequence mediated by Hg2+ ions, a BODIPY-based fluorescent probe decorated with an alkynyl hydrazone motif responds rapidly and selectively to Hg2+ ions, with a detection limit of 29 nM and a fluorescence turn-on ratio of 15-fold. With the addition of Hg2+ ions, the BODIPY-based alkynyl hydrazone transforms into a pyrazole ring to mediate a turn-on emission response clearly observable to the naked eye under visible light excitation.Article Citation - WoS: 4Citation - Scopus: 4A Cyclopalladated Bodipy Construct as a Fluorescent Probe for Carbon Monoxide(Wiley, 2022) Çevik Eren, Merve; Eren, Ahmet; Dartar, Suay; Tütüncü, Büşra Buse; Emrullahoğlu, MustafaBy introducing a palladium ion into the backbone of BODIPY, we devised a cyclopalladated BODIPY construct that was almost non-emissive in the absence of any analyte but became highly fluorescent upon interacting with carbon monoxide (CO) in solution and in living cells. A process of ortho-carbonylation and depalladation mediated by the specific binding of CO to palladium, promoted the release of the heavy atom from the fluorophore and consequently generated a fluorescence signal with an exceptionally high (60-fold) enhancement ratio.Article Citation - WoS: 3Citation - Scopus: 1Transition Metal Salt Promoted, Green, and High-Yield Synthesis of Silver Nanowires for Flexible Transparent Conductive Electrodes(Wiley-Blackwell, 2021) Sarısözen, Sema; Tertemiz, Necip Ayhan; Arıca, Tuğçe Aybüke; Polat, Nahit; Kocabaş, Çoşkun; Mert Balcı, Fadime; Balcı, SinanSilver nanowires (AgNWs) have attracted considerable interest from both academia and industry owing to their excellent electrical, optical, and chemical properties. For large-scale synthesis of AgNWs, the polyol method involving ethylene glycol, a toxic alcohol, has been widely used. We herein report on a facile, green, high yield, transition metal salt promoted, open atmosphere method for the synthesis of high quality AgNWs in a glycerol-water mixture. We have shown that transition metal salts have a strong influence on the morphology of AgNWs. Importantly, in the presence of copper(II) chloride, AgNWs with a high aspect ratio of around 400 (length, 36 μm; diameter, 90 nm) were obtained. Additionally, for the first time, we have demonstrated AgNWs based flexible transparent conductive electrodes (TCEs) on poly(sodium 4-styrenesulfonate) (PSS) treated polyethylene terephthalate (PET) substrate with a sheet resistance of 34 Ω/sq and transmittance of 91 % at 550 nm. The PSS layer on the PET substrate generated a highly hydrophilic surface, which boosts interaction of AgNWs with the PET surface. We envision that our results would play a significant role both in the synthesis of AgNWs with high aspect ratio and also in designing new rigid and flexible TCEs having high transmittance and low sheet resistance for applications especially in printable solar cells, organic light emitting diodes, and high performance flexible electronics.
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