Fonksiyonel konjuge polimerler

The considerable role of conjugated polymers (CPs) in emerging synthetic bio-applications, optical, electronic, diodes, and display technologies, represents the promising way in which considerable endeavors have been directed towards the realization of many aspects of conducting organic polymers. Conducting polymers are known as "synthetic metals", making them fundamental materials in many research fields because of their outstanding characteristics. They exhibit both excellent conductivity and high mechanical strengths and processability. The use of CPs as an excellent immobilization platform for biomolecules led to the development of efficient biosensors, which were easy to process, had the ability to conduct electricity at any desired level, had a low cost, and straightforward preparation techniques. CPs provide high surface area, adjustable morphology by arranging the thickness of the polymer film and offer extensive stability of the enzymes incorporated in them. Furthermore, these materials also facilitate structural and electronic modifications which can be used in detecting a target compound in any test solution. The polymer structure can be tuned to accomplish the desired properties, producing a sensitive and reproducible microenvironment for biological reactions to mimic the naturally occurring environments of the biological molecules. Among vast number of CPs, poly(p-pheneylene)s (PPP)s and polythiophenes (PT)s are the most promising class of polymer in terms of relatively high photoluminescence, electroluminescence quantum efficiencies and thermoxidative stability and so on. Conjugated structure of CPs can create excellent one-dimensional surface for energy transport of electrons and strong UV absorption. Especially, their fluorescence feature is one of the most susceptible to environmental change and this allows for eminent selectivity in signaling reporter group materials and provides advantages for CPs to be used in sensor technologies including pH sensors, temperature sensors and recently developed biosensors. Recent innovative strategies for the syntheses of functional polymeric structures bearing polypeptides, amino-rich and water soluble groups have received enormous interest in the fields of biomedicine, drug delivery, biomineralization, bioconjugations, and tissue engineering. Taking account of the unique advantages of these strategies, in this thesis, we focused on the combination of PPPs and PTs with polypeptide, amino and water soluble groups in the same conjugated backbone. In the first part of thesis, a simple and efficient approach for the electrochemical deposition of polypeptides as bio-based covering materials for surface design is described. The method involves N-carboxyanhydride (NCA) ring-opening polymerization from its precursor to form a thiophene-functionalized polypeptide macromonomer (T-Pala), followed by electropolymerization. The obtained conducting polymer, namely polythiophene-g- polyalanine (PT-Pala), was characterized and utilized as a matrix for biomolecule attachment. The biosensing applicability of PT-Pala was also investigated by using glucose oxidase (GOx) as a model enzyme to detect glucose. The designed biosensor showed a very good linearity for 0.01–1.0 mM glucose. Finally, the antimicrobial activities of newly synthesized T-Pala and PT-Pala were also evaluated by using the disc diffusion method. In the second part of thesis, we report a novel approach for fabrication of multifunctional conjugated polymers, namely poly(p-phenylene)s (PPPs) possessing polypeptide (poly-L-lysine, PLL) and hydrophilic poly(ethylene glycol) (PEG) side chains. The approach is comprised of the combination of Suzuki coupling and in situ N-carboxyanhydride (NCA) ring-opening polymerization (ROP) processes. First, polypeptide macromonomer was prepared by ROP of the corresponding NCA precursor using (2,5-dibromophenyl) methanamine as an initiator. Suzuki coupling reaction of the obtained polypeptide and PEG macromonomers both having dibromobenzene end functionality using 1,4-benzenediboronic acid as the coupling partner in the presence of palladium catalyst gave the desired polymer. A different sequence of the same procedure was also employed to yield polymer with essentially identical structure. In the reverse sequence mode, low molar mass monomer (2,5-dibromophenyl)methanamine, and PEG macromonomer were coupled with 1,4- benzenediboronic acid in a similar way followed by ROP of the L-Lysine NCA precursor through the primary amino groups of the resulting polyphenylene. In the third part of thesis, a novel approach for bioconjugation associated with a fluorescent conjugated polymer is demonstrated. For this purpose, a conjugated polymer, poly(p-phenylene) (PPP), with lateral substituents, namely primary amino groups and poly(ethylene glycol) (PEG) chains, as a potential building block for polymer bioconjugates was synthesized and characterized. The synthesis was achieved through Suzuki polycondensation reaction in the presence of Pd(PPh3)4 catalyst by using independently prepared PEG and amino functionalized dibromo benzenes in conjunction with benzene diboronic acid. For the evaluation of the bioactive PPP labeled with folic acid (FA) as a potential targeted cell imaging probe, HeLa and A549 cancer cells were used. Cytotoxicity assay showed that the polymer was not toxic to either of the cells. Additionally, the fluorescence images showed that, depending on the level of the FA receptors on the cell surfaces, the fluorescent intensity in HeLa cells was obviously higher than A549 cells when treated with FA conjugated PPP-NH2-g-PEG polymer. The resulting FA/PPP-NH2-g-PEG conjugate was successfully used as a bioconjugate for targeting and specifically imaging FA receptor positive HeLa human cervical cancer cells. Summary, we successfully achieved the systhesis, characterization and some bioapplications of complex macromolecular architecture based on conjugated polymers bearing polypeptide, water soluble pendant ,PEG, and primary amine groups. The systhesis of polypeptide squences were achieved by NCA-ROP technique based on transformation of α-amino acids to urethane derivatives which have possibility to obtain polypeptides in the well-designed and desicive control of molecular weight with one spot intra-molecular cyclization reaction in the presence of primary amino functional initiators. We succesfully used the primary amino functional thiophene and phenyl compounds as NCA-ROP initiator to obtain macromonomers having electropolymerization ability and possibility to give Suzuki coupling polymerization. After the obtaining of conjugated polymers bearing polypeptide and primary amine groups based on PPP and PTs, some biofunctional material was used in the step of bioapplications.