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A Sensitive Capacitive Biosensor for Protein a Detection Using Human IgG Immobilized on an Electrode Using
Kosin Teeparuksapun1,2, Martin Hedström2, Bo Mattiasson2
1Science Program, Department of General Education, Faculty of Liberal Arts, Rajamangala University of Technology Srivijaya, Songkhla 90000, Thailand.
Sensors (Basel, Switzerland)
|January 11, 2022
Summary
A new capacitive biosensor detects protein A using gold electrodes and layer-by-layer assembly. Optimized probe height enhances sensitivity for detecting trace amounts of protein A in antibody isolation.
Area of Science:
- Biosensing
- Nanotechnology
- Electrochemistry
Background:
- Protein A is crucial in purifying therapeutic monoclonal antibodies.
- Capacitive biosensors offer label-free detection methods.
- Optimizing probe architecture is key for biosensor sensitivity.
Purpose of the Study:
- To develop a capacitive biosensor for sensitive protein A detection.
- To investigate the impact of layer-by-layer (LbL) probe height on assay sensitivity.
- To establish a quantitative detection range and limit of detection for protein A.
Main Methods:
- Fabrication of gold electrodes via thermal evaporation and photolithography.
- Layer-by-layer assembly of thiourea and gold nanoparticles (AuNPs) to create probes.
- Immobilization of human IgG and detection of protein A binding via capacitance changes.
Main Results:
- Biosensor sensitivity increased with initial probe layer growth.
- Excessive probe thickness led to decreased measurement sensitivity.
- Linear detection range from 1 x 10-16 to 1 x 10-13 M was achieved.
- Limit of detection was determined to be 9.1 x 10-17 M.
Conclusions:
- The developed capacitive biosensor effectively detects protein A.
- Probe height optimization is critical for maximizing biosensor performance.
- The system shows potential for detecting trace protein A in antibody purification processes.
