Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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  • Master Thesis
    Fluorescent Gold Ion Sensors: Design, Synthesis and Imaging
    (01. Izmir Institute of Technology, 2021) Kaya, Beraat Umur; Emrullahoğlu, Mustafa
    Of all transition metals, gold has long sustained attention owing to its unique chemical and physical properties. Beyond that, the ease of processing gold allows its use in science, industry, and in various chemical, biological, and medical applications. For example, gold is used in medicine to treat rheumatoid arthritis, asthma, cancer, and brain and skin lesions. However, the extensive use of gold compounds can adversely impact the natural environment and biological systems due to their potential toxicity. For those reasons, identifying trace amounts of gold species in solution and cell media is crucial. Unlike the detection methods of atomic absorption spectroscopy, atomic emission spectroscopy, and inductively coupled plasma spectrometry, fluorescence-based detection methods offer easy sample preparation, rapid response, high sensitivity, reproducibility, and efficiency, all at a low cost. Today, various types of fluorescent sensors selective to gold ions have been designed, typically with BODIPY, fluorescein, rhodamine, naphthalimide, and coumarin-based fluorophores. In the work for this thesis, for the first time an enyne-derived BODIPY-based sensor was designed and synthesised to identify Au3+ ions, after which photophysical changes in the presence and absence of the analyte were examined both in solutions and in cells.
  • Master Thesis
    Design and Synthesis of a Bodipy Based Probe for Cadmium Ions
    (01. Izmir Institute of Technology, 2021) Cebeci, Miray; Emrullahoğlu, Mustafa
    Given the severely toxic effects of heavy metals on living systems and the environment in general, identifying and quantifying heavy metal ions in synthetic samples and in vivo are highly significant activities. One such heavy metal, cadmium, allows only a low level of tolerable exposure and can thus have fatal consequences or cause critical health problems such as ostial disorders, nephrotic syndromes, various types of cancer even in extremely low concentrations. Although several standard techniques for detecting cadmium have been used, including atomic absorption and emission spectroscopy and inductively coupled plasma mass spectrometry, all of them require complex instruments that are also expensive, time-consuming to use, and hardly portable. For that reason, sensitive, selective, less labour-intensive methods of detecting cadmium ions are greatly needed. In response, fluorogenic or chromogenic methods afford high analyte sensitivity and selectivity, easy sample preparation, and easy monitoring, all with affordable instrumentation. Against that background, this thesis reports the design, synthesis, and development of a fluorescent molecular sensor that can detect Cd2+ ions within spectroscopic behavior and living cells. In the design, based on the mechanism of intramolecular charge transfer (ICT), borondipyrromethene (BODIPY) dye was used as a signal reporter due to its unique properties, and di-(2-picolyl)amine (DPA) was chosen to represent the recognition unit. Altogether, the sensor offers rapid response, high selectivity, and high sensitivity in detecting Cd ions is reversible with the aid of CN- and can be used to efficiently image Cd2+ species in vitro.
  • Master Thesis
    Design and Synthesis of a Bodipy Based Probe for Mercury Ions
    (01. Izmir Institute of Technology, 2021) Tütüncü, Büşra Buse; Emrullahoğlu, Mustafa
    The detection of heavy metal ions in living systems and aqueous environments has attracted significant attention in recent years, especially the detection of mercury, one of the most toxic heavy metals on Earth. To reduce mercury's lethal effects on the human body, animals, and marine life trace amounts of mercury species can be detected by using classical spectroscopic techniques for example atomic absorption and emission spectroscopy, high-performance liquid chromatography, and inductively coupled plasma mass spectrometry. However, because those techniques are time-consuming and expensive, fluorescence analysis, which offers high selectivity and sensitivity, has emerged as a suitable alternative for detecting mercury species. In the work presented here, a new BODIPY -based fluorescent probe functionalised with a phenylhydrazine unit was designed and synthesised for the selective and sensitive detection of mercury species. The probe's detection limit was determined to be 29 nM, and the probe could detect mercury species in living cells without any changes in cell morphology.
  • Master Thesis
    Desing and Synthesis of Bodipy Based Photosensitizers for Photodynamic Therapy
    (Izmir Institute of Technology, 2019) Dartar, Suay; Emrullahoğlu, Mustafa; Emrullahoğlu, Mustafa
    Photodynamic therapy is a promising modality for the non-invasive treatment of several cancerous and non-cancerous diseases. PDT is more preferable than other therapies due to its low damage to non-targeted tissues and its controllable characteristics. The therapy involves the activation of a photosensitizer under light illumination to generate singlet oxygen which is the cytotoxic agent employed against the cancerous tissues. Thus, there is currently a great effort to develop various photosensitizers. Among these, BODIPY based photosensitizers are distinguished due to certain characteristics, including excellent photostability, high extinction coefficients and high resistance to photobleaching. In this study, we aimed to synthesize and develop new BODIPY based photosensitizers for the use of photodynamic therapy agents. BODIPY skeleton was devised using the dibromoethylene unit from the 2,6-positions in order to enhance the π-conjugation system for red shift to longer wavelengths resulting in a deep penetration of tissue. Heavy atoms such as bromine were introduced to the BODIPY core to ensure the transition from singlet states to triplet states via intersystem crossing for the generation of singlet oxygen. Photophysical properties and spectroscopic measurements of photosensitizers were performed successfully. Finally the photodynamic activities of photosensitizers in cancerous cells were also investigated.
  • Master Thesis
    Design and Synthesis of Bodipy Based Phosgene Sensor
    (Izmir Institute of Technology, 2018) Sayar, Melike; Emrullahoğlu, Mustafa
    Phosgene was used in World War I as a chemical warfare agent and now, it is used as only a chemical intermediate in the industrial field according to laws. Because of the result of exposure to phosgene, its detection plays a significant role to protect civilians against terrorist attacks, and also to warn people if there would be any leakage in industrial facilities. To determine the phosgene, there are several methods like gas chromatography, which has several disadvantages such as poor portability and sensitivity and high cost or requiring of sophisticated procedures. However, fluorescence analysis has high sensitivity, resolution, and simplicity which provides real-time visual detection of analytes. For this thesis, boron-dipyrromethene (BODIPY) dye was used as the signal reporter by synthesizing the new BODIPY derivative, to benefit from its outstanding photophysical properties. In addition to that, as the main purpose of this thesis, this is the first time an o-aminobenzyl amine group was used due to be the phosgene-specific reactive motif for research in phosgene sensing which is an investigation of photophysical properties of designed BODIPY derivative in the absence and presence of phosgene.