Development of a biosensor system to analysis of a breast cancer biomarker her3

Bu tezde, meme kanserinin erken teşhisine yönelik bir biyosensör sistemi tasarlanmıştır. Bunun için indinyum kalay oksit (ITO) elektrot yüzeyinde 3-aminopropiltrietoksisilan (3- APTES) ile kendinden oluşan monotabaka (KOT) oluşturulmuştur. Bu yöntem ile anti-HER3’ ün yüzeye kovalent olarak bağlanması sağlanmıştır. Her bir immobilizasyon adımı ve tasarlanan biyosensörle elden edilen HER3 ölçümleri döngüsel voltametri (CV) ve elektrokimyasal impedans spektroskopisi (EIS) yöntemleri kullanılarak incelenmiştir. Biyosensörün başarılı sonuçlar vermesi için tüm adımlar optimize edilmiştir.In this thesis, a new biosensor system is designed for the early diagnosis of breast cancer. For this, on the surface of indiumtinoxide (ITO) electrode was formed by self assembled monolayers (SAM) with (3-aminopropyl)triethoxysilane (3-APTES). With this method, the anti-HER3 was provided to bind covalently on the surface. Immobilization steps and determination of HER3 by designed biosensor were analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). All steps of the biosensor has been optimized to succeed results

Fabrication of a highly sensitive disposable immunosensor based on indium tin oxide substrates for cancer biomarker detection

Anti-HER-3 antibody was used for the first time in a disposable immunosensor based on indium tin oxide (ITO) substrate for HER-3 quantification. Anti-HER-3 was immobilized onto ITO substrate by 3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde. This highly sensitive immunosensor was capable of detecting concentrations of HER-3 down to the femtogram/ml level by investigating changes in the charge transfer resistance (R-ct) using electrochemical impedance spectroscopy (EIS). Construction of ITO layers was carefully investigated using a broad range of techniques such as voltammetry, EIS, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Meanwhile, in an immunosensor system, the single frequency impedance technique was first used for characterization of interaction between HER-3 and anti-HER-3. Eventually, the proposed ITO-based immunosensor was applied to artificial serum samples spiked with HER-3. (C) 2013 Elsevier Inc. All rights reserved.TUBITAK (Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109 T 172]; Namik Kemal University Scientific Research Projects FundNamik Kemal University [NKUBAP.00.10.YL.13.03]; Namik Kemal University Scientific and Technological Research CenterNamik Kemal UniversityThis work was financially supported by TUBITAK (Scientific and Technological Research Council of Turkey, project 109 T 172). In addition, we thank the Namik Kemal University Scientific Research Projects Fund (project NKUBAP.00.10.YL.13.03) and the Namik Kemal University Scientific and Technological Research Center

A Novel Biosensing System Using Biological Receptor for Analysis of Vascular Endothelial Growth Factor

An immunosensor with rapid and ultrasensitive response for vascular endothelial growth factor (VEGF) has been built up with 4-aminothiophenol (4-ATP) onto the gold surfaces. Quantitative analysis of VEGF was performed by recording the impedance changing of the gold electrode surface by binding of VEGF. The human vascular endothelial growth factor receptor 1 (VEGF-R1, Flt-1) was used as a biorecognition element for the first time in the literature. VEGF-R1 was covalently immobilized via 4-ATP self-assembled monolayer formed on gold thin film covered surface. Construction of the biosensor was carefully characterised by the techniques such as electrochemistry and electrochemical impedance spectroscopy. In order to characterize impedance data, Kramers-Kronig transform was performed on the experimental impedance data. The limit of detection of the immunosensor for qualitative detection was 100 pg/mL while the LOD for quantitative detection could down to 100 pg/mL by using the VEGF-R1 based biosensor. Finally, artificial serum samples spiked with VEGF was analyzed by the proposed immunosensor to investigate useful of the biosensor for early biomarker diagnosis.TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109 T 172]The authors greatly appreciate the support of the TUBITAK (The Scientific and Technological Research Council of Turkey, Project number: 109 T 172)

Electrochemical biosensor based on self-assembled monolayers modified with gold nanoparticles for detection of HER-3

We have developed a new immunological biosensor for ultrasensitive quantification of human epidermal growth factor receptor-3(HER-3). In order to construct the biosensor, the gold electrode surface was layered with, hexanedithiol, gold nanoparticles, and cysteamine, respectively. Anti-HER-3 antibody was covalently attached to cysteamine by glutaraldehyde and used as a bioreceptor in a biosensor system for the first time by this study. Surface characterization was obtained by means of electrochemical impedance spectroscopy and voltammetry. The proposed biosensor showed a good analytical performance for the detection of HER-3 ranging from 0.2 to 1.4 pg mL(-1). Kramers-Kronig transform was performed on the experimental impedance data. Moreover, in an immunosensor system, the single frequency impedance technique was firstly used for characterization of interaction between HER-3 and anti-HER-3. Finally the presented biosensor was applied to artificial serum samples spiked with HER-3. (C) 2014 Elsevier B.V. All rights reserved.TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109T 172]This work was supported by a grant from TUBITAK (The Scientific and Technological Research Council of Turkey, Project number: 109T 172)

In vitro effects of amiodarone on coronary artery bypass grafts

Background: This study aims to investigate the effects of amiodarone on the most commonly used grafts, internal thoracic artery (ITA), saphenous vein (SV), and radial artery (RA) in organ bath. Methods: Twenty patients (16 males, 4 females; mean ages 58.4 +/- 9.9 years; range 38 to 80 years) who underwent isolated coronary artery bypass graft (CABG) surgery between May 2008 and October 2008 were included in this study. Internal thoracic artery, saphenous vein, and radial artery grafts were harvested. Specimens were taken to laboratory in +4 degrees C Krebs solution. Specimens were suspended in 10 ml organ bath containing Krebs solution. Results: Amiodarone caused relaxation in all grafts (ITA, RA, SV) between 10(-9)-10(-3,5) M concentration in a dose dependent manner (p<0.01). Maximum relaxation rates (mean) induced by amiodarone were 78.9%, 74.9% and 66.5% for ITA, RA and SV, respectively. Conclusion: Although we did not evaluate the endothelium-independent relaxation response in this study, higher rates of relaxation response were observed with ITA grafts comparing to other grafts, and these results were compatible with literature. According to the results of this study, amiodarone-class III antiarrhythmic agent- caused vasodilation in all three grafts in vitro. Vasodilator effect of amiodarone on grafts may help to increase patency rates