Distance-based analytical device integrated with carbon nanomaterials for sarcosine quantification in human samples

Area of Science:

• Biomarker detection
• Analytical chemistry
• Nanotechnology

Background:

• Prostate cancer diagnosis and prognosis rely on monitoring biomarkers like sarcosine.
• Existing methods for sarcosine detection can be expensive and complex.
• There is a need for rapid, cost-effective, and user-friendly diagnostic tools.

Purpose of the Study:

• To develop a straightforward distance-based paper analytical device (dPAD) for sarcosine quantification.
• To utilize carbon nanodots (CDs) as a peroxidase-like nanozyme, replacing expensive enzymes.
• To provide a rapid and accessible method for prostate cancer-related biomarker monitoring.

Main Methods:

• A dPAD sensor was fabricated with sarcosine oxidase (SOx) and CDs in the sample zone and TMB in the detection zone.
• Sarcosine in human samples triggers hydroxyl radical production via SOx and CD catalysis.
• Capillary action drives radical flow to the detection zone, oxidizing TMB and causing a color change proportional to sarcosine concentration.

Main Results:

• The dPAD demonstrated a linear working range of 12.5–35.0 nmol L⁻¹ with R² = 0.9959.
• A low detection limit of 10.0 nmol L⁻¹ was achieved, suitable for clinical urinary sarcosine determination.
• High precision (RSD ≤ 4.58%), excellent selectivity, and recovery rates (98.67–101.50%) were observed in human urine samples.

Conclusions:

• The developed dPAD is a cost-effective, user-friendly, and sensitive analytical tool for sarcosine quantification.
• This method shows promise for the rapid diagnosis and prognosis of prostate cancer and related symptoms.
• The dPAD concept is adaptable for detecting other biomolecules, broadening its analytical applications.