Uricase biofunctionalized plasmonic sensor for uric acid detection with APTES-modified gold nanotopping

Area of Science:

• Biosensing and Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Current uric acid detection methods lack sensitivity and selectivity for point-of-care use.
• Plasmonic sensors show promise but require performance enhancements for clinical applications.

Purpose of the Study:

• To develop a biofunctionalized sensor using surface plasmon resonance for quantifying uric acid at physiologically relevant concentrations.
• To improve the sensitivity and selectivity of plasmonic sensors for uric acid detection.

Main Methods:

• Covalent immobilization of uricase enzyme onto the sensor probe using EDC/NHS crosslinking agents.
• Characterization using atomic force microscopy and Fourier transform infrared spectroscopy.
• Analysis of binding kinetics using the Langmuir adsorption isotherm model.

Main Results:

• The sensor demonstrated a high binding affinity (298.83 (mg/dL)^-1) and sensitivity (0.0755°/(mg/dL)).
• Achieved a low limit of detection (0.095 mg/dL) and excellent selectivity against common interferents.
• A distinct resonance angle shift of 0.3706° was observed for 0.5 mg/dL uric acid, differentiating it from interferents.

Conclusions:

• The biofunctionalized plasmonic sensor significantly enhances uric acid detection capabilities.
• This technology holds promise for clinical diagnostics and point-of-care applications, potentially transforming healthcare outcomes.