Immuno-battery: A single use self-powered immunosensor for REASSURED diagnostics

Area of Science:

• Biomedical Engineering
• Electrochemistry
• Biosensors

Background:

• Conventional diagnostic devices often require external power sources, limiting their accessibility and affordability.
• Paper-based electrochemical immunoassays are promising for point-of-care diagnostics but can be limited by power requirements.

Purpose of the Study:

• To develop a novel, self-powered paper-based immunosensor for biomarker detection.
• To demonstrate the feasibility of using an "Immuno-Battery" for energy generation during the sensing process.
• To evaluate the performance and sensitivity of the self-powered immunosensor for C-reactive protein (CRP) detection.

Main Methods:

• Development of a paper-based immunosensor utilizing magnesium as an anode and HRP-labeled antibodies as a cathodic catalyst.
• Integration of self-powering capabilities, generating energy from the biomarker-induced reaction.
• Testing the device under resistive load to measure operational voltage and power density.
• Assessing the limit of detection (LOD) for CRP in artificial samples and comparing it to existing methods.

Main Results:

• The Immuno-Battery achieved operational voltages above 1.55 V and power densities ranging from 40 to 571 μW cm⁻².
• The self-powered operation did not compromise sensitivity, with a demonstrated LOD of 20 ± 2 ng mL⁻¹ for protein detection.
• A specific LOD of 269 ± 39 ng mL⁻¹ was achieved for C-reactive protein (CRP), comparable to commercial kits.

Conclusions:

• A novel self-powered paper-based immunosensor (Immuno-Battery) has been successfully developed and demonstrated.
• The device generates sufficient power for potential integration with electronic readout circuits.
• This technology paves the way for sustainable, affordable, and accessible digital diagnostic devices.