Novel amperometric immunosensors based on iridium oxide matrices

Area of Science:

• Electrochemistry
• Biosensor Technology
• Materials Science

Background:

• Development of novel immunosensors is crucial for sensitive and specific biomolecule detection.
• Immobilization matrices significantly impact immunosensor performance, including antibody loading and activity.
• Iridium oxide (IrOx) thin films offer unique properties for potential biosensor applications.

Purpose of the Study:

• To develop novel immunosensors using electrochemically grown iridium oxide (IrOx) thin film matrices.
• To evaluate antibody immobilization efficiency and analytical properties of the IrOx matrix.
• To demonstrate the applicability of IrOx-based immunosensors for detecting specific biomarkers like IgG and human transferrin.

Main Methods:

• Antibody immobilization within electrochemically grown IrOx thin film matrices.
• Electrochemical immunoassay techniques were employed to evaluate antibody loading and sensor response.
• Amperometric detection at +420 mV using hydroquinone diphosphate (HQDP) as the enzyme substrate for IgG detection.

Main Results:

• Optimal anti-IgG loading was achieved with 400 microg/ml anti-IgG during oxide growth.
• IgG detection showed linear dose-response from 10-200 ng/ml with a low detection limit of 8 ng/ml.
• The IrOx matrix successfully immobilized anti-transferrin antibodies, enabling detection of human transferrin.

Conclusions:

• IrOx matrices provide a novel and effective method for immunosensor fabrication.
• The highly porous and hydrophilic nature of IrOx supports high antibody loading and activity.
• This fabrication method is suitable for mass production, offering an easy and economical approach to biosensor development.