Bioassay of prostate-specific antigen (PSA) using microcantilevers.

Area of Science:

• Biotechnology
• Nanotechnology
• Biomedical Engineering

Background:

• Accurate diagnosis of complex diseases like cancer necessitates sensitive detection of multiple proteins.
• Microcantilever beams exhibit measurable mechanical bending upon specific biomolecular binding, detectable via optical methods.
• The specificity and sensitivity of microcantilever-based detection under clinically relevant conditions remain critical research questions.

Purpose of the Study:

• To evaluate the specificity and sensitivity of microcantilever-based detection for disease-related proteins.
• To demonstrate the clinical relevance of microcantilever technology for cancer diagnostics.
• To explore the potential of microcantilevers as a common platform for various label-free biomolecular interaction analyses.

Main Methods:

• Utilized microcantilevers of varying geometries for biomolecular detection.
• Quantitatively detected two forms of prostate-specific antigen (PSA).
• Performed detection in a complex biological matrix (human serum) containing interfering proteins (HSA, HP) at clinically relevant concentrations.

Main Results:

• Successfully detected PSA across a wide concentration range (0.2 ng/ml to 60 μg/ml).
• Demonstrated detection in the presence of high concentrations of human serum albumin (HSA) and human plasminogen (HP) (1 mg/ml).
• Confirmed the label-free, specific, and sensitive nature of the microcantilever detection method.

Conclusions:

• Microcantilever technology is a clinically relevant diagnostic technique for prostate cancer detection.
• The technique's sensitivity and specificity are suitable for analyzing disease biomarkers in complex biological samples.
• Microcantilever-based sensing offers a versatile platform for high-throughput, label-free analysis of diverse biomolecular interactions, including protein-protein binding, DNA hybridization, and drug discovery.