A Portable Immunosensor with Differential Pressure Gauges Readout for Alpha Fetoprotein Detection

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanomaterials

Background:

• Point-of-care testing (POCT) demands portable, affordable, and simple diagnostic devices.
• Traditional diagnostic methods often lack the speed and accessibility required for immediate clinical decisions.

Purpose of the Study:

• To develop a novel POCT system utilizing a Differential Pressure Gauge (DPG) for sensitive analyte detection.
• To demonstrate the feasibility of using Pt/SiO2 nanospheres for signal amplification in a DPG-based sensor.
• To establish a portable and reliable method for detecting alpha-fetoprotein (AFP) in biological samples.

Main Methods:

• Synthesis and antibody modification of Platinum/Silicon Dioxide (Pt/SiO2) nanospheres.
• Development of a sandwich immunocomplex assay for AFP detection.
• Utilizing the catalytic decomposition of hydrogen peroxide by Pt to generate oxygen and pressure changes detected by DPG.
• Optimization of assay conditions and validation using serum samples.

Main Results:

• The DPG-based sensor showed a direct correlation between pressure signal and AFP concentration (10–200 ng/mL).
• Achieved a low detection limit of 3.4 ng/mL for AFP.
• Successfully applied the sensor for AFP detection in human serum samples with satisfactory accuracy.

Conclusions:

• The developed DPG-based sensor offers a promising strategy for portable and sensitive POCT.
• The system demonstrates convenient operation, reliable results, and flexible apparatus for biological analysis.
• This approach holds potential for broader applications in point-of-care diagnostics.