Photothermal biosensing integrated with microfluidic paper-based analytical device for sensitive quantification of...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Sarcosine is a potential biomarker for prostate cancer diagnosis.
• Existing detection methods may lack sensitivity, affordability, or point-of-care capabilities.

Purpose of the Study:

• To develop a novel photothermal biosensing system for quantitative sarcosine detection.
• To integrate this system into a microfluidic paper-based analytical device (PT-μPAD) for practical applications.

Main Methods:

• Utilized gold nanoparticles (AuNPs) as nanozymes and photothermal substrates.
• Developed a PT-μPAD where H2O2 generated from sarcosine etches AuNPs, causing a measurable temperature change.
• Employed a 532 nm laser and infrared thermometer for detection.

Main Results:

• Achieved a linear range of 10.0–40.0 nmol L−1 with an LOD of 32.0 pmol L−1.
• Demonstrated high selectivity and recovery rates (99.05–102.11%) in human samples.
• Validated the PT-μPAD against ELISA for urine samples, showing no significant difference.

Conclusions:

• The developed PT-μPAD offers a sensitive, selective, and affordable method for sarcosine monitoring.
• This biosensor is suitable for prostate cancer diagnostics and has potential for broader point-of-care biomarker detection.