Functionalization and fabrication of polymer based device platform architectures for sensor applications

Söylemez, Saniye
In this thesis, two types of sensors: Conjugated polymer based amperometric biosensors and a chemiresistive sensor (polymer/SWCNT) for clinical and food applications were designed, fabricated and characterized. Three chapters in this thesis focused on ethanol, glucose and cholesterol biosensors based on functional polymer/MWCNT composition, different peptide sequence containing polymer, and also copolymer of two different functional monomers, respectively. After successful electrochemical deposition of the polymers on the graphite electrode surfaces, immobilization of alcohol oxidase (AOx), glucose oxidase (GOx) and cholesterol oxidase (ChOx) were carried out. Since conjugated polymer based biosensors are recognized to be a next generation building architecture for highly sensitive and fast biosensing systems, in this thesis, it is aimed to create new biosensor systems for the quantitative detection of ethanol, glucose and cholesterol which are thought to play an important role to prevent several diseases. To construct a chemiresistive sensor, nanowires (NWs), especially carbon nanotubes (CNTs), as the basis for chemiresistor research were used. In this work, single walled carbon nanotubes (SWCNTs) due to their excellent conductivity, exceptional aspect ratios, and numerous methods available for functionalization were favored. The first step generates a surface wherein P4VP-SWCNT dispersion was spray-coated and covalently linked to the surface. The P4VP dispersant not only displays a favorable interaction with SWCNTs to stabilize debundled dispersion, but it also allows further modifications on its nucleophilic pyridyl nitrogens with alkyl halides. In the second step, a post-functionalization of P4VP-SWCNT surface via reacting with 2- bromoethanol was implemented. Finally, GOx was immobilized on the modified surface to detect glucose in beverages. As a conclusion, all devices constructed in this thesis present four new examples in biosensing applications that overcome challenges associated with analysis time, selectivity and also requirement of pretreatment of the samples. Sensor performances were also evaluated for each sensor. Additionally, surface features of the sensors and molecules were fully characterized using NMR, SEM, XPS, CV, FT-IR and Raman techniques depending on the type of sensor. To further test the sensing performance, the sensors were tested towards their specific analytes and showed promising feasibility for the quantitative analysis in beverages and human blood samples.


Synthesis of bistriphenylamine- and benzodithiophene-based random conjugated polymers for organic photovoltaic applications
CETIN, Asli; ISTANBULLUOGLU, Cagla; HACIOGLU, Serife Ozdemir; CEVHER, ŞEVKİ CAN; Toppare, Levent Kamil; Çırpan, Ali (2017-11-15)
In this study, donor-acceptor random polymers containing benzotriazole acceptor and bistriphenylamine and benzodithiophene donors, P1 and P2, were successfully synthesized by Stille coupling polymerization. The effect of bistriphenylamine moiety and thiophene -conjugated linker on electrochemical, spectroelectrochemical, and optical behaviors of the polymers were investigated. Optoelectronic properties and photovoltaic performance of the polymers were examined under the illumination of AM 1.5G, 100 mWcm(-2)...
Fabrication of a promising immobilization platform based on electrochemical synthesis of a conjugated polymer
Buber, Ece; SÖYLEMEZ, SANİYE; UDUM, YASEMİN; Toppare, Levent Kamil (2018-07-01)
Since conjugated polymers are an important class of materials with remarkable properties in biosensor applications, in this study, a novel glucose biosensor based on a conjugated polymer was fabricated via the electropolymerization of the monomer 10,13-bis(4-hexylthiophen-2-yl)dipyridol[3,2-a:2',3'-c]phenazine onto a graphite electrode surface. Glucose oxidase (GOx) was used as the model biological recognition element. As a result of the enzymatic reaction between GOx and glucose, the glucose amount was det...
Bioactive surface design based on conducting polymers and applications to biosensors
Ekiz, Fulya; Toppare, Levent Kamil; Timur, Suna; Department of Biotechnology (2012)
An underlying idea of joining the recognition features of biological macromolecules to the sensitivity of electrochemical devices has brought the concept of biosensors as remarkable analytical tools for monitoring desired analytes in different technological areas. Over other methods, biosensors have some advantages including high selectivity, sensitivity, simplicity and this leads to solutions for some problems met in the measurement of some analytes. In this context, conducting polymers are excellent alter...
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The synthesis , spectroscopic and electrochemical properties of a series of donor-acceptor (DA) type polymers by changing the donor unit (thiophene, dithienopyrrole) polymer backbone were investigated.The synthesized CoP1 and CoP2 were designed to investigate the effect of copolymerization and insertion of perylene tetracarboxylic dimide (PDI) on the structure of benzotriazole (BTz) based polymers. For CoP1 1,7-dibromo-perylene diimide,4,7-dibromo-2-dodecyl-2H-benzo[d][1,2,3]triazole and 2,5 bis(tributylsta...
Fabrication of microfluidic devices for dielectrophoretic and acoustophoretic applications using high precision machining
Soheila, Zenaili; Çetin, Barbaros; Özer, Mehmet Bülent; Süleyman, Büyükkoçak (2014-07-03)
In this study, the fabrication of microfluidic devices for dielectrophoretic and acoustophoretic based applications with high-precision CNC machining has been presented. For both devices, molds out of stainless steel have been fabricated, and polymer molding is implemented. For dielectrophoretic device, the metal electrodes have been fabricated using high-precision machining and embedded into the device during the molding process. For acoustophoretic device, piezoelectric slides have been embedded into the ...
Citation Formats
S. Söylemez, “Functionalization and fabrication of polymer based device platform architectures for sensor applications,” Ph.D. - Doctoral Program, Middle East Technical University, 2018.