Telomeraz Aktivitesi Tayinine Yönelik Yüksek Enerji Dönüşümlü Floresan Partiküllerin Biyosensör Olarak Kullanımı

Abstract

Within the scope of this thesis study, it is aimed to develop a descriptive fluorophore-probe that can detect telomerase from body fluid with silica nanoparticles by using the high energy up-conversion feature of rare earth elements and the sensitive selection ability of antibody interaction processes. Telomerase is an enzyme that has been reported in the literature to be highly activated in cells with immortal ability (cancer cells). Based on this, a biosensor that will detect the secretion amount of telomerase may be a hope in treatment for general cancer screening and its early diagnosis. Cancer, which is a very common and mortal disease today, is a disease that can be treated if diagnosed at an early stage. Anomalies in the amount and activity of telomerase provide preliminary information to scientists in this context. For this reason, it is aimed to develop a fluorophore probe that can detect the presence of telomerase in body fluid with new generation probes. In this study, silica nanoparticles were chosen as the main body. Silica nanoparticles were synthesized by the method known as the Stöber method in the literature, and auxiliary linking groups (NH, OH, etc.) were attached to them through modification treatments. As a preliminary test, the modified silica nanoparticles were made with the "transferrin" antibody, which is related to iron, which has a physiologically and biologically important place in the organism. The transferrin antibody was successfully bound to basic silica nanoparticles, and its antigen capture and detection ability and capacity were measured and reported by assays. These preliminary experiments, conducted before the trial of high energy conversion ‘’silica@lanthanide’’ UCNPs probes with unique emission properties for the early diagnosis of cancer, also became a biosensor to measure the amount of transferrin antigen in body fluid. After the successful completion of the preliminary tests, the europium lanthanide element was placed in the core of the synthesized silica particles in order to ensure higher and sharper signal differences received from the protein to be measured, and this structure was supported with an organic material that will serve as an antenna to make the signal received higher and more permanent. Then, Si@Eu (Eu doped silica NPs) particles were modified and decorated with "telomerase" antibody. Experiments were carried out with these fluorophore nanoprobes, which were prepared to capture telomerase antigen. Ambient absorption signals were evaluated by interacting with commercial antigen and antigens extracted from real cancer cells. In these analyses, surface characterization, surface potential and electron microscope examinations at every stage of modification, FT-IR, electrophoresis, UV spectrometry and spectrofluorometry analyzes were performed and the results were successfully reported. The logical data obtained as a result of this study were as follows; 1) Silica nanoparticles have been turned into a probe in preliminary trials and have shown promise as a medical sensor that will allow total iron binding capacity (TIBC) analysis. 2) Silica nanparticles were converted into fluorophore probes and became up-conversion (UCNPs) probes, which managed to capture commercial antigen and real antigen at significant rates. 3) In electrophoresis analyses, it was seen that the band images, dissociation behaviors and sharpness obtained as a result of the competition of UCNPs nanoprobes with the commercial dye Cy2@Green were not only biosensors, but also a good marker. In summary, a stable immunoprobe was developed thanks to the useful and processable structures of silica nanoparticles, the emission stability of lanthanides and the high selectivity of antibody-antigen interactions. . A sensor platform to be used in the early diagnosis of cancer, which is the main subject of the thesis, has been successfully produced.