Application of paper-supported printed gold electrodes for impedimetric immunosensor development

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Nanomaterials

Background:

• Development of cost-effective and disposable biosensors is crucial for point-of-care diagnostics.
• Existing biosensor platforms often require complex fabrication and are not easily recyclable.
• Need for sensitive and reliable detection methods for biomarkers like C-reactive protein (CRP).

Purpose of the Study:

• To report the formation and operational mode of an affinity biosensor for CRP detection.
• To demonstrate a novel fabrication scheme using inkjet-printed gold electrodes on paper substrates.
• To establish a recyclable and inexpensive point-of-care diagnostic platform.

Main Methods:

• Fabrication of paper-based substrates with inkjet-printed gold nanoparticle electrodes.
• Layer-by-layer assembly of biorecognition elements: biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody.
• Detection of protein assembly formation using electrical impedance spectroscopy (impedimetry).
• Verification using Surface Plasmon Resonance (SPR), X-ray Photoelectron Spectroscopy (XPS), and Atomic Force Microscopy (AFM).

Main Results:

• Successful formation and detection of multi-layered supramolecular protein assembly on printed gold electrodes.
• Demonstrated the feasibility of impedimetric detection of biosensor layer growth.
• Validated the biosensor assembly using SPR, XPS, and AFM characterization techniques.
• Achieved a recyclable and inexpensive biosensor test-structure.

Conclusions:

• A viable scheme for developing paper-based affinity biosensors using inkjet-printed electrodes has been established.
• Impedimetric analysis provides an effective electrical method for monitoring biosensor layer formation.
• The developed platform offers a promising approach for low-cost, recyclable, point-of-care diagnostic applications.