Browsing by Author "Ecik, Esra Tanriverdi"

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BODIPY Precursors and Their Cyclotriphosphazene Derivatives: Synthesis, Photochemical Properties and Their Application in PDT
(Pergamon-Elsevier Science Ltd, 2024) Gul, Elif Yildiz; Karatas, Elanur Aydin; Dogan, Hatice Aydin; Ciftci, Gonul Yenilmez; Ecik, Esra Tanriverdi
Photodynamic therapy (PDT) is a treatment method consisting of common combination of oxygen, light energy and a light absorbing molecule called a photosensitizer. In this work, four new compounds consisting of BODIPY precursors and BODIPY-cyclotriphosphazene derivatives were synthesized to investigate the PDT effects. The chemical structures of the compounds were characterized and then their photophysical properties were determined by spectroscopic techniques. The precursor BODIPYs and their cyclotriphosphazene derivatives exhibited similar properties such as strong absorption intensity, high photostability and low fluorescence profile in the NIR region. Additionally, the singlet oxygen production capacities of these compounds were determined using the photobleaching technique of 1,3-diphenylisobenzofuran (DPBF) under light illumination. By introducing iodine atoms into the molecule, which are responsible for the intersystem transition (ISC) enhancement, a more efficient singlet oxygen production was achieved in both the iodinated-BODIPY and its cyclotriphosphazene derivative. Anticancer activities of the precursor BODIPYs and their cyclotriphosphazene derivatives in the absence and presence of light illumination were evaluated on cancerous cell lines (PC3 and DU145) and non-tumorigenic prostate epithelial PNT1a cell. The compounds triggered the death of cancer cell PC3 the more significantly in the presence of red light compared to the healthy cells (PNT1a).
Enhanced Photodiode Performance: Au/Boron-dipyrromethene Structure Unveiling High Photosensitivity and Efficiency
(Elsevier Sci Ltd, 2025) Duman, Songul; Gul, Elif Yildiz; Aydemir, Murat; Selvitopi, Harun; Ozer, Tuba Oznuluer; Ecik, Esra Tanriverdi
In this study, the classical boron-dipyrromethene (4,4- difuoro-4-borata-3a-azonia-4a-aza-s-indacene, BODIPY) unit (C1), its halogenated derivative (C2), and disytryl derivative (C3), which are known for their absorption properties in the near-infrared (NIR) region, were synthesized. Chemical and photophysical investigations were carried out to reveal the complex features of the molecules using a range of spectroscopic techniques and their energies were calculated by Density Functional Theory (DFT) with the same basis set. The BODIPY thin films were coated on n-Si substrates using a spin coater to examine the effect of interlayer on photodiode/photovoltaic properties and Au/BODIPY (C1, C2, C3)/n-Si/Ag photodiodes having rectifying behavior were fabricated. The thermionic emission theory (TET) and modified Norde's functions were utilized to determine the rectification ratio, ideality factor, series resistance, and barrier height values of diodes. The values of barrier height, ideality factor, and rectification ratio at +/- 2 V were calculated as 0.81 eV, 1.83 and 2.47x103 for the Au/C1/n-Si/Ag diode, 0.83 eV, 1.63, and 7.06 x103 for the Au/C2/n-Si/Ag diode and 0.84 eV, 1.51 and 2.14x104 for the Au/C3/ n-Si/Ag diode in the dark from the TET, respectively. The values of FF (%) and efficiency were calculated as 38 and 1.51 for the Au/C1/n-Si/Ag diode, 47 and 2.03 for the Au/C2/n-Si/Ag diode, and 56 and 3.68 for the Au/ C3/n-Si/Ag diode under 100 mW/cm2 illumination, respectively. With remarkable electrical properties, the Au/ C3/n-Si/Ag photodiode stood out among the others, performing better in both dark and light conditions. Therefore, the produced diodes based on the BODIPY thin film can be employed as photodiodes/photovoltaics in optoelectronic applications.
Erlotinib-Modified Bodipy Photosensitizers for Targeted Photodynamic Therapy
(Wiley-VCH Verlag GmbH, 2023) Gul, Elif Yildiz; Karatas, Elanur Aydin; Dogan, Hatice Aydin; Karatas, Omer Faruk; Cosut, Buenyemin; Ecik, Esra Tanriverdi
Photodynamic therapy (PDT) is an innovative, non-invasive and highly selective therapeutic modality for tumours and non-malignant diseases. BODIPY based molecules can function as new generation photosensitizers (PSs) in various PDT applications. Despite numerous conjugated PS systems are available, BODIPYs containing erlotinib lagged behind other photosensitizer units. In this study, smart photosensitizers containing BODIPY, erlotinib and hydrophilic units were prepared for the first time, their physicochemical properties and PDT effects were investigated. Compared with non-halogenated compound, halogenated derivatives possessed much lower fluorescence profile as well as the good ROS generation ability under red light. In vitro PDT studies were performed on both healthy (PNT1a) and prostate cancerous cells (PC3) to determine the selectivity of the compounds on cancerous cells and their effects under light. The halogenated conjugates, exposed to low dose of light illumination exhibited potent activity on cancer cell viability and the calculated IC50 values proved the high phototoxicity of the photosensitizers. It was also determined that the PSs have very low dark toxicity and that the light illumination and ROS formation are required for the initiation of the cell death mechanism. As a result, erlotinib modified BODIPYs could serve as promising agents in anticancer photodynamic therapy.
Fabrication of Hybrid Photodiode Systems: Bodipy Decorated Cyclotriphosphazene Covalently Grafted Graphene Oxides
(Royal Society Chemistry, 2020) Ozcan, Emrah; Aksoy, Burcu Topaloglu; Ecik, Esra Tanriverdi; Dere, Aysegul; Karabulut, Abdulkerim; Yakuphanoglu, Fahrettin; Cosut, Bunyemin
Combination of graphene sheets with various organic/inorganic functional groups could enhance the applications of graphene-based hybrid materials. Among them, BODIPY dyes are critically important due to their unique photonic properties and cyclophosphazenes are an excellent scaffold to anchor two or more chromophores. Thus, many attractive photonic characteristics can be shown in graphene/cyclophosphazene-BODIPY hybrid systems. Herein, the construction, synthesis and development of graphene-based hybrids (GO-CP-BODIPY) for enhanced photosensor applications were shown. Moreover, the photo-electrochemical properties of the novel hybrids were studied in particular using a photoconductivity measurement system. The produced photodiodes were quite sensitive to exposure light and exhibited photoconducting behavior under illumination light. The values of ideality factor and barrier height, which are two of the basic electrical parameters of a photodiode, were determined with the help of current-voltage characteristics for different light intensities. In addition to the dark current, it was found that a photocurrent was formed by the effect of illumination. Furthermore, the capacitanceversustime measurements performed at different light intensities showed that the device exhibited photocapacitive behavior. It is considered that the produced device in this study could be used in organic-based optoelectronic applications, especially as a photodiode or photosensor.