Self-powered competitive immunosensor driven by biofuel cell based on hollow-channel paper analytical devices

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Electrochemistry

Background:

• Microfluidic paper-based analytical devices (μ-PADs) offer a low-cost platform for diagnostics.
• Enzymatic biofuel cells (BFCs) can provide self-powering capabilities for analytical devices.
• Sensitive detection of biomarkers like carcinoembryonic antigen (CEA) is crucial for early disease diagnosis.

Purpose of the Study:

• To develop a mediator-less and compartment-less BFC integrated into μ-PADs for self-powered CEA detection.
• To utilize specific biocatalysts and electrode modifications for enhanced sensitivity and signal transduction.
• To establish a stable, reproducible, and sensitive platform for protein detection.

Main Methods:

• Fabrication of a BFC using silver nanoparticles/graphene modified paper electrodes within hollow channels of μ-PADs.
• Immobilization of glucose dehydrogenase (GDH)-gold nanoparticle bioconjugate modified with CEA on the bioanode.
• Immobilization of nanoporous PtNi/bilirubin oxidase (BOD) on the biocathode.
• Correlation of CEA concentration with the BFC output signal.

Main Results:

• The BFC-based immunosensor demonstrated a wide linear detection range for CEA from 1 pg mL⁻¹ to 0.5 μg mL⁻¹.
• A low detection limit of 0.7 pg mL⁻¹ for CEA was achieved.
• The sensor exhibited high sensitivity, stability, and reproducibility in detecting CEA.
• The output signal of the BFC decreased with increasing CEA concentration due to reduced CEA-Au-GDH bioconjugate on the bioanode.

Conclusions:

• The developed BFC-based self-powered immunosensor is a promising platform for sensitive and reproducible CEA detection.
• The integration of BFCs into μ-PADs offers a viable strategy for creating self-powered analytical devices.
• This approach holds potential for the detection of other protein biomarkers.