Hydrogel-based suspension array for biomarker detection using horseradish peroxidase-mediated silver precipitation

Area of Science:

• Biomolecular detection
• Nanotechnology in diagnostics
• Hydrogel-based assays

Background:

• Current diagnostic tools for biomolecules are often complex, expensive, and unsuitable for point-of-care (POC) settings.
• There is a need for sensitive, cost-effective, and rapid diagnostic methods for protein quantification in body fluids.
• Personalized therapy and advanced medical diagnostics demand accessible detection platforms.

Purpose of the Study:

• To develop a novel, sensitive, and cost-effective detection platform for biomolecule quantification.
• To leverage horseradish peroxidase (HRP)-mediated silver precipitation in hydrogel microparticles for biomarker detection.
• To demonstrate the platform's capability for rapid, point-of-care (POC) analysis of proteins, using vascular endothelial growth factor (VEGF) as a model.

Main Methods:

• Antibody-immobilized, porosity-tuned poly(ethylene glycol) diacrylate (PEGDA) hydrogel microparticles were synthesized.
• Horseradish peroxidase (HRP)-mediated silver precipitation was employed for signal amplification.
• Suspension array principles were utilized for sensitive quantification of VEGF.
• VEGF quantification in cell culture supernatants from breast cancer cell lines (MDA-MB-231 and MCF-7) was performed.

Main Results:

• Silver deposition intensity directly correlated with the concentration of vascular endothelial growth factor (VEGF).
• Achieved a highly sensitive detection limit of 5.2 ± 1.0 pg/mL for VEGF.
• Demonstrated a rapid assay time of 2 hours, surpassing conventional technologies in speed.
• Successfully quantified VEGF production by aggressive and non-aggressive breast cancer cell lines, validating practical applicability.

Conclusions:

• The developed hydrogel microparticle detection platform offers superior sensitivity and speed compared to existing methods.
• The assay's reliance on simple instrumentation facilitates its adaptability for point-of-care (POC) diagnostics.
• This novel platform holds significant potential for the rapid and cost-effective quantification of clinically relevant biomarkers.
• The method's ability to analyze VEGF from cancer cell lines highlights its utility in biological and clinical research settings.