Micro-flow Immunosensor Based on Thin-film Interdigitated Gold Array Microelectrodes for Cancer Biomarker Detection

Area of Science:

• Biosensor Technology
• Electrochemistry
• Biomarker Detection

Background:

• Carbohydrate antigen 125 (CA125) is a significant biomarker, particularly for ovarian cancer.
• Accurate and sensitive detection of CA125 is crucial for early diagnosis and monitoring.
• Existing detection methods can be complex or lack sensitivity.

Purpose of the Study:

• To develop a micro-flow, label-free impedimetric biosensor for CA125 detection.
• To functionalize interdigitated gold array (IDA) electrodes for enhanced immunosensing.
• To evaluate the analytical performance of the developed CA125 biosensor.

Main Methods:

• Fabrication of thin-film interdigitated gold array (IDA) microelectrodes.
• Electropolymerization of anthranilic acid (AA) on IDA surfaces.
• Covalent immobilization of anti-CA125 monoclonal antibodies.
• Electrochemical impedance spectroscopy (EIS) for CA125 detection.
• Characterization using electrochemical techniques and scanning electron microscopy (SEM).

Main Results:

• Successful development of a label-free impedimetric immunosensor.
• Optimized sensor demonstrated sensitive CA125 detection over a range of 0-100 U/mL.
• Achieved a low limit of detection (LOD) of 7 U/mL for CA125.
• Sensor exhibited good analytical performance and stability.

Conclusions:

• The developed micro-flow impedimetric biosensor offers a sensitive and label-free platform for CA125 detection.
• Electropolymerization of AA and antibody immobilization provide an effective strategy for immunosensor development.
• This biosensor holds potential for clinical applications in CA125 monitoring.