Rapid and highly-sensitive uric acid sensing based on enzymatic catalysis-induced upconversion inner filter effect

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Uric acid (UA) is a key biomarker for various health conditions.
• Accurate detection of UA is crucial for clinical diagnostics.
• Existing detection methods may lack sensitivity or simplicity.

Purpose of the Study:

• To develop a novel and simple fluorescence-based detection method for uric acid (UA).
• To utilize NaYF4:Yb(3+), Tm(3+) upconversion nanoparticles (UCNPs) as a core component for UA sensing.
• To validate the method's efficacy in complex biological matrices such as human serum.

Main Methods:

• Fabrication of NaYF4:Yb(3+), Tm(3+) upconversion nanoparticles (UCNPs).
• Enzymatic oxidation of UA by uricase to produce hydrogen peroxide.
• Oxidation of o-phenylenediamine (OPD) by hydrogen peroxide to form oxOPD.
• Fluorescence quenching of UCNPs by oxOPD via inner filter effects (IFE).

Main Results:

• A linear correlation was established between UA concentration and UCNPs fluorescence quenching.
• The method demonstrated a wide linear response range from 20 to 850μM for UA.
• A low detection limit of 6.7μM for UA was achieved under optimized conditions.
• Successful detection of UA in human serum samples was demonstrated, highlighting matrix compatibility.

Conclusions:

• The developed fluorescence method offers a sensitive and simple approach for UA detection.
• NaYF4:Yb(3+), Tm(3+) UCNPs serve as effective fluorescent probes for UA sensing.
• The nanosensor shows significant potential for clinical applications in diagnosing UA-related conditions using biological samples.