Label-Free Electrochemical Sensor for CD44 by Ligand-Protein Interaction

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensor Technology

Background:

• Biomarker detection is crucial for advanced biodiagnostics in research and clinical settings.
• Developing novel analytical platforms for molecular capture and quantitation remains a significant challenge.

Purpose of the Study:

• To develop a label-free electrochemical sensor for CD44 detection.
• To utilize ligand-protein interactions for sensitive and selective biomarker quantitation.

Main Methods:

• Assembled carbon nanotube composites on electrodes to enhance conductivity.
• Conjugated hyaluronic acid (HA) to carbon nanotubes via electrostatic interaction with PDDA.
• Performed direct electrochemical sensing of CD44 without post-labeling.

Main Results:

• Achieved a dynamic range of 0.01-100 ng/mL and a detection limit of 5.94 pg/mL for CD44.
• Demonstrated high selectivity, reproducibility (RSD 2.57%), and 14-day stability.
• Successfully applied the sensor to detect CD44 in human serum and cancer cells.

Conclusions:

• The developed sensor provides a sensitive, label-free method for CD44 detection.
• This work advances biosensor design for ligand-protein interactions in biodiagnostics.
• The findings contribute to the development of interfaces for diagnostic biosystems.