Label-free immunosensor for prostate-specific antigen based on single-walled carbon nanotube array-modified...

Area of Science:

• Electrochemistry
• Biosensor Technology
• Nanomaterials

Background:

• Prostate cancer diagnosis relies on biomarkers like total prostate-specific antigen (T-PSA).
• Existing detection methods may lack sensitivity or require complex labeling procedures.
• Development of sensitive, label-free detection methods is crucial for clinical applications.

Purpose of the Study:

• To fabricate and characterize a label-free electrochemical immunosensor for T-PSA detection.
• To evaluate the sensor's performance, including sensitivity, selectivity, and detection limit.
• To assess the potential clinical applicability of the developed immunosensor.

Main Methods:

• Fabrication of microelectrode arrays modified with single-walled carbon nanotubes (SWNTs).
• Immobilization of T-PSA monoclonal antibody (T-PSA-mAb) onto SWNTs.
• Label-free detection of T-PSA using differential pulse voltammetry (DPV) by monitoring current signals from tyrosine and tryptophan oxidation.

Main Results:

• The electrochemical immunosensor demonstrated label-free detection of T-PSA.
• Current signals increased upon T-PSA interaction with immobilized T-PSA-mAb on SWNTs.
• The sensor exhibited high selectivity, with minimal response to bovine serum albumin (BSA).
• A low detection limit of 0.25 ng/mL for T-PSA was achieved.

Conclusions:

• The developed label-free electrochemical immunosensor shows high sensitivity and selectivity for T-PSA detection.
• The sensor's performance, with a detection limit below the clinical cut-off, is promising for prostate cancer diagnostics.
• This technology offers a potential advancement for early prostate cancer screening and clinical applications.