A miniaturized optoelectronic biosensor for real-time point-of-care total protein analysis

Area of Science:

• Optoelectronics
• Biomedical Engineering
• Analytical Chemistry

Background:

• Accurate total protein measurement is crucial for diagnosing and monitoring various medical conditions.
• Current gold-standard methods often require complex laboratory equipment and trained personnel.
• There is a need for portable, sensitive, and accurate diagnostic tools for point-of-care applications.

Purpose of the Study:

• To develop and validate a miniaturized optoelectronic sensor for quantifying total protein concentration in biological samples.
• To integrate a novel fluorescence assay with the sensor for real-time detection.
• To assess the sensor's performance against established clinical laboratory methods.

Main Methods:

• Fabrication of a handheld optoelectronic sensor incorporating a vertical cavity surface emitting laser (VCSEL) and photodetector.
• Development of a custom fluorescence assay utilizing the protein-induced fluorescence enhancement (PIFE) phenomenon.
• Characterization of sensor performance using standard curves in buffer, human blood, and urine, and comparison with a benchtop fluorimetric microplate reader.

Main Results:

• The VCSEL biosensor/PIFE assay system demonstrated sensitivity and accuracy comparable to gold-standard methods for total protein measurement.
• Real-time detection of protein concentration changes was achieved through the PIFE assay.
• Validation in patient serum and urine samples confirmed the system's reliability for clinical diagnostics.

Conclusions:

• A miniaturized, portable optoelectronic sensor system has been successfully developed for total protein quantification.
• The VCSEL biosensor combined with the PIFE assay offers a sensitive, accurate, and real-time measurement solution.
• This technology holds potential for improving point-of-care diagnostics and patient monitoring, particularly for conditions like diabetes.