A disposable, highly sensitive biosensing system

Haptoglobin (Hp) is a glycoprotein and is produced as an acute phase plasma component and synthesized in many different tissues. The glycoprotein has many biochemical and metabolic roles such as hosting defence responses to infection and inflammation, acting as an antioxidant, antibacterial and anti-inflammatory roles, and as an inhibitor of prostaglandin synthesis. Moreover, it is reported that the levels of Hp are elevated in neuromyelitisoptica. Because of the metabolic importance of Hp, its sensitive and selective analysis is also of vital importance to researchers.

In this research, a highly sensitive and disposable Indium Tin Oxide (ITO) based biosensing tool was developed. Featuring the considerable superiorities of ITO substrates, suitability for disposable biosensors, low cost, and repeatability, a novel anti-Hp based biosensor was created with a very low detection limit. Anti-Hp antibody was utilized in this research for fabrication of such a disposable biosensor integrated with ITO substrates for the first time. The new biosensor presents highly analytical performance with a linear range 0.2 fg/mL -- 1fg/mL. Kramers-Kronig Transform was performed on the experimental impedance data. The single frequency impedance technique was first used for characterization of interaction between Haptoglobin and anti-Haptoglobin.

Our research suggests that ITO substrates can be used in other biosensing strategies with high reproducibility and repeatability. Besides, the single frequency impedance technique can be performed in the evaluation of association and dissociation relations of bimolecular interactions, successfully.