Fabrication of a highly sensitive disposable immunosensor based on indium tin oxide substrates for cancer biomarker detection
By Canbaz, Mehmet Çetin & Sezgintürk, Mustafa Kemal
Published in Analytical Biochemistry
2014
Abstract
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 (Rct) 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.