Development of a Polymersome Blood Ammonia Assay Coupled with a Portable Near-Infrared Fluorometer

Area of Science:

• Biomarker detection
• Nanotechnology for diagnostics
• Point-of-care testing

Background:

• Ammonia is a critical biomarker for liver disease.
• Current clinical assays for blood ammonia are not point-of-care.
• A need exists for rapid, accessible ammonia detection methods.

Purpose of the Study:

• To develop a polymersome-based formulation for point-of-care blood ammonia sensing.
• To combine this formulation with a portable fluorometer for a complete assay.
• To validate the assay's performance in fresh whole blood.

Main Methods:

• Developed ammonia-selective polymersomes loaded with a pH-sensitive near-infrared (NIR) fluorescent dye.
• Tested polymersome performance with ammonia-spiked fresh whole blood using a plate reader.
• Validated the assay with a portable fluorometer using ammonia-spiked mouse blood.

Main Results:

• Polymersomes demonstrated high linearity (R² = 0.9948) in sensing ammonia in whole blood within 5 minutes.
• The assay successfully detected ammonia using a portable fluorometer with fresh mouse blood.
• The assay requires only 3 μL of blood for rapid, linear ammonia detection.

Conclusions:

• NIR fluorescent polymersomes enable rapid and linear ammonia sensing in whole blood.
• The developed assay is compatible with a portable fluorometer for point-of-care use.
• This technology shows promise for clinical translation in liver disease diagnostics.