Master Degree / Yüksek Lisans Tezleri

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

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Department: search.filters.department.Thesis (Master)--İzmir Institute of Technology, BioengineeringSubject: search.filters.subject.Thin films

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  • Master Thesis
    Development of Conductive Oxide Based Thin Film Modified Electrodes and Biosensors Applications
    (Izmir Institute of Technology, 2021) Özyüzer, Lütfi; Yurttaş, Betül; Özyüzer, Lütfi; Erdem Gürsan, Kadriye Arzum; 01. Izmir Institute of Technology; 04.05. Department of Pyhsics; 04. Faculty of Science
    From the first biosensor produced in 1956 to the present day, biosensors have been highly developed and diversified. In biosensor manufacturing, thin films have become a rapidly emerging field. Depending on the thin film material used, thin films have many advantageous properties for biosensors, such as high surface-to-volume ratio, conductivity, stability, specificity, biocompatibility, and good electrocatalytic activity. Dopamine is a neurotransmitter that has a significant impact on the emergence and treatment of certain diseases such as Alzheimer's and Parkinson's diseases. Dopamine monitoring is important for the prevention of these diseases, and it is a favorable option to use biosensors, which are useful and practical tools, instead of time-consuming and expensive conventional methods. For this purpose, in this thesis, a non-enzymatic electrochemical biosensor based on thin film electrodes was developed for monitoring dopamine levels. The electrodes were developed by deposition of Zn2SnO4 (ZTO) thin film on ITO thin film substrate by DC magnetron sputtering technique. The properties of the electrodes were determined by thickness, optical transmittance, XRD and SEM analysis. Electrochemical analysis, namely CV, EIS and DPV measurements, were performed before and after the electrodes were sonicated and modified with APTES before their application to the voltammetric detection of dopamine. In addition, electrochemical measurements were performed before/after sonication, APTES modification. Dopamine was detected by a voltammetric method using DPV technique. Furthermore, experiments in the presence of interferents such as ascorbic acid (AA), uric acid (UA) etc. showed that the thin film electrodes can be successfully applied for voltammetric determination of dopamine. As a result, the biosensor technology developed in this study has the potential to be wearable in the future, enabling non-invasive monitoring of dopamine levels in body fluids such as saliva, tears and sweat.
  • Master Thesis
    The Effect of Metal Doping on Tio2 for Photocatalytic Applications
    (Izmir Institute of Technology, 2019) Alduran, Yeşim; Öztürk, Orhan; Özyüzer, Lütfi; Özyüzer, Lütfi; Öztürk, Orhan; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Recently, the photocatalysis method has been an active research area as a promising solution for environmental cleaning method, leading to self-cleaning and sterilization of solar cell surfaces to produce water dissociation reaction. Titanium dioxide (TiO2) is the most suitable semiconductor for photocatalytic applications due to its high oxidation potential and high efficiency when irradiated by ultraviolet light (UV). Undoped and Ruthenium (Ru+) doped TiO2 thin films were prepared using magnetron sputtering technique. All thin films were grown on SLG different ratios like 1 sec, 3 secs, 5 secs and 7 secs to set shutter position in magnetron sputter target. Transparent substrate SLG is coated with nearly 50 nm TiO2 thin films without compromising any optical properties. Samples were heat treated for two hours at 500°C to get the anatase phase crystal structure. The crystallization peaks of TiO2 are proved to get the anatase phase. Photocatalytic activity of TiO2 thin films are determined after 1, 3, 5 and 24 hours with organic pollution as a methylene blue dye degradation under UV light. The degradation of methylene blue was investigated kinetically and photocatalytic activity rate constants of the photocatalysts were calculated. All thin films could not reach super hydrophilicity state. Undoped TiO2 contact angle 47.309o and Ru doped TiO2 63.218o were evaluated. The photocatalytic degradation percentage of Methylene Blue was reached 87%, after 24 hours of UV irradiation, when using Ru-doped TiO2 thin film. Consequently, the anatase phase of Ru-doped TiO2 thin films are found best photocatalytic activity in self-cleaning performance.