Prostate-specific antigen immunoassays on the BioCD.

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Immunodiagnostics

Background:

• The BioCD is a spinning-disc interferometric biosensor designed for capturing target antigens from biological samples.
• Antibodies are immobilized on the BioCD surface to facilitate specific antigen capture.
• Prostate-specific antigen (PSA) is a key biomarker for prostate cancer detection.

Purpose of the Study:

• To determine the ideal detection limit for prostate-specific antigen (PSA) using the BioCD biosensor.
• To evaluate the impact of the number of antibody spots on PSA detection sensitivity.
• To assess PSA detection limits in both simple protein backgrounds and human serum.

Main Methods:

• Utilized a BioCD with 12,500 printed target antibody spots and reference protein spots for PSA measurement.
• Performed statistical analysis to project the PSA detection limit as a function of averaged spot pairs.
• Employed a standard 96-well BioCD immunoassay format with 32 target and reference spots for serum analysis.
• Used a sandwich assay with a nonfluorescent mass tag for PSA detection in diluted human serum.

Main Results:

• Averaging approximately 10,000 spot pairs yielded a 3-sigma detection limit of 60 pg/ml for PSA in a 2 mg/ml simple protein background.
• The standard 96-well BioCD immunoassay format achieved a PSA detection limit of 1 ng/ml in 3:1 diluted female human serum.

Conclusions:

• The BioCD biosensor demonstrates high sensitivity for PSA detection, with performance improving with an increased number of averaged spots.
• The optimized BioCD system shows promise for sensitive PSA quantification in complex biological matrices like serum.
• This technology offers a potential platform for developing advanced diagnostic tools for prostate cancer screening.