Potentiometric enzyme immunoassay using miniaturized anion-selective electrodes for detection

Area of Science:

• Biochemistry
• Analytical Chemistry
• Immunotechnology

Background:

• Prostate-specific antigen (PSA) is a key biomarker for prostate cancer diagnosis and monitoring.
• Traditional immunoassays for PSA detection often involve complex procedures and expensive equipment.
• There is a need for simpler, more cost-effective diagnostic platforms for PSA detection.

Purpose of the Study:

• To develop and validate a novel enzyme-linked immunosorbent assay (ELISA) for prostate-specific antigen (PSA) detection.
• To utilize potentiometric detection of 6,8-difluoro-4-methylumbelliferone (DiFMU) for enhanced sensitivity and simplicity.
• To establish the feasibility of potentiometric immunoassays as a viable alternative for in vitro diagnostics.

Main Methods:

• Developed a PSA-specific ELISA using anti-human PSA capture antibodies in microtiter plates.
• Employed a beta-galactosidase-labeled PSA tracer antibody for signal amplification.
• Utilized potentiometric microelectrodes with an anion-exchanger membrane for the detection of the DiFMU anion, a product of DiFMUG hydrolysis.

Main Results:

• The developed assay demonstrated a linear concentration range for PSA detection from 0.1 to 50 ng/mL in human serum.
• The potentiometric detection method showed selectivity governed by the lipophilicity of the DiFMU anion.
• The assay confirmed the applicability of potentiometric detection in diagnostic PSA assays.

Conclusions:

• Potentiometric ELISA offers a sensitive and reliable method for PSA detection in human serum.
• The simple methodology and low cost make this approach a feasible alternative for in vitro diagnostic platforms.
• This technology holds promise for the development of advanced diagnostic tools for prostate cancer screening and management.