Development of electrochemical impedance spectroscopy based immunosensor for ferritine determination

Ferritin is one of the most important markers of iron deficiency anemia, which is very common in human populations around the world. In addition, it is important as an acute phase reactant in many cases of inflammation and in some cases as a tumor marker. Due to these important reasons, a new impedimetric immunosensor for the determination of ferritin was developed under the project. As a basic principle, an affinity - based biosensor system based on antigen - antibody interaction was developed and the changes on the sensor surface were observed by electrochemical impedance spectroscopy. Ferritin determination was carried out by way of the mentioned changes. Antigen - antibody interaction was carried out between the anti-ferritin antibody and the ferritin biomolecules. The sensitivity of the immunosensor system has been increased as a result of various modifications of the sensor surfaces used. Anti-ferritin antibodies were covalently immobilized onto the gold electrode surface via a self-assembled monolayer (SAM) of 11 - mercaptoundecanoic acid (11 – MUA). Ferritin antigens were detected by electrochemical impedance spectroscopy (EIS) as a result of their interaction with surface-immobilized antibodies. The developed biosensor system has a linear range of 2.5 to 400 pg/mL ferritin. The reproducibility and repeatability results of the biosensor are highly consistent.