Master Degree / Yüksek Lisans Tezleri

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

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Subject: search.filters.subject.Gold nanoparticles

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Now showing 1 - 3 of 3
  • Master Thesis
    Development of Mitochondria Targeted Gold Nanorods
    (Izmir Institute of Technology, 2019) Uçak, Hande; Özçelik, Serdar; Özçelik, Serdar; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Lung cancer has the largest number of lives for the global pattern of cancer death. However, the percentage of the cancer treatment is too low. Gold nanoparticles have a widely range in terms of biomedical applications in diagnosis, imaging because of their unique optical properties, simple synthesis techniques, biocompatibility and suitable for easy surface change. Redox reactions in the mitochondria generates a potential called as mitochondria membrane potential. The aim of the study is to design mitochondria targeted gold nanorods and to observe how the designed gold nanorods effects the mitochondria membrane potential by targeting the mitochondria on A549 and BEAS-2B cell lines. Gold nanorods were utilized by seed growth mediated method and the surface bioconjugation was performed with triphenyl phosphonium cation as a mitochondria targeted molecule. Poly (sodium-p-styrene sulfonate) was used to prevent aggregation during the bioconjugation process. Gold nanorods which had 30 nm x 10 nm in length and diameter depending on SEM images had well-defined absorption bands 513 nm and 774 nm in wavelength. Mito-pot analysis with the fluorescent intensity ratio and colocalization analysis with light intensity for targeting gold nanorods to mitochondria showed that the accumulation on mitochondria for TPP-GNR was higher than PSSGNR. TPP-GNR was more toxic than PSS-GNR for both of cell lines by investigations of MTT viability test. TPP-GNR targeted to mitochondria and it affected fundamental cellular functions in mitochondria. To concluded that accumulation on mitochondria was accomplished for TPP-GNR and the decreasing of mitochondria membrane potential was observed on this study.
  • Master Thesis
    Green Synthesis of Metal Nanoparticles and Their Applications as Plasmonic Substrates
    (Izmir Institute of Technology, 2018) Elveren, Beste; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan; 04.01. Department of Chemistry; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    Gold nanoparticles (GNPs) have been widely used in diagnostic, tissue engineering, and drug delivery fields, in the last decades. Generally, reducing gold salts to zero valent gold has been accomplished by harsh chemicals and strong reducing agents, which cause toxicity and eventually limiting the bioapplications. Green synthesis is a newly developing methodology to synthesize GNPs. Especially natural products and plants extracts are commonly preferred for green synthesis based on their natural content. Biological molecule-capped GNPs, are more biofriendly and biocompatible nano-materials that can be used for varied applications.1-3 Sensor applications; varying from biosensing to environmental analysis, are an important field that GNPs were intensively utilized.4-5 Cyanide ion (CN-) has been considered as one of the main pollutants of water, because of its rapid discharge. CN- is currently being used in industry such as; polymer synthesis6, noble metal mining7, pest control8, plastics production etc., at large scale. However, there is an unmet need for CN- detection and monitoring. Colorimetric detection of CN- that utilizes GNPs has been done by several researchers.9-10 However, in all these studies reduction of GNPs were done by strong reducing agents. Green synthesis of GNPs eliminates the toxic side-products that can be harmful to both environment and human health. To overcome this problem green synthesized GNPs were used to establish the sensor platform, which can be further employed for CN- detection. Oxidation of GNPs in the presence of cyanide molecules is a direct-forward, colorimetric and optical method that requires no toxic chemicals; therefore it is a greener approach towards CN- detection in water resources.
  • Master Thesis
    Development of Gold Nanoparticle-Based Plasmonic Assay Platform for Esherichia Coli Detection
    (Izmir Institute of Technology, 2017) Erdoğan, Duygu; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu; 04.01. Department of Chemistry; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    The traditional methods for pathogen detection have long detection time and insufficient sensitivity. Optical methods can overcome these drawbacks. There are solution based nanoparticle growth in the literature to enhance a surface sensitivity for biosensing applications. In this project, surface refractive index (RI) sensitivity was enhanced on solid support via gold growth to develop a label free, simple and costeffective methodology for bacteria screening. The gold nanoparticles (GNPs) were grown on solid support by using 20 μl of HAuCl4 / 80 μl of NH2OH at varied incubation times. Firstly, about 20 nm GNPs were synthesized and immobilized on polystyrene surfaces. Then, these GNPs were utilized as seed particles, and grown on solid support. During GNPs growth, a red shift in the plasmonic wavelength was observed. Morphological characterization showed that almost uniform gold growth could be achieved. The plasmonic platform sensitivity was validated by varied concentrations of sucrose, ethanol and BSA solutions, showing that the plasmonic platform gave a response to any small RI change. Next, two different E.coli bacterial strains’ adsorption was tested. Adsorption screenings for about 107 E.coli DH5-alpha cells/ml and 107 E.coli BL21(DE3) cells/ml in Phosphate Buffer Saline were made on growth gold surfaces. Further, E.coli BL21(DE3) containing milk and apple juice were also adsorbed on these gold surfaces with a 30 min incubation time. The results showed that these gold surfaces exhibit higher binding kinetics for bacteria. Therefore, the proposed LSPR-based label free methodology can be an alternative to the bacteria screening in water or food samples.