Amperometric uric acid sensors based on polyelectrolyte multilayer films

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Amperometric detection of uric acid is crucial for clinical diagnostics.
• Developing selective and sensitive biosensors remains a challenge.
• Multilayer films offer a versatile platform for biosensor construction.

Purpose of the Study:

• To develop a novel amperometric sensor for uric acid detection.
• To utilize polyelectrolyte multilayer (PEM) films and uricase (UOx) for enhanced sensor performance.
• To investigate the effect of multilayer structure and deposition conditions on sensor sensitivity and selectivity.

Main Methods:

• Fabrication of a permselective multilayer film on a platinum electrode using poly(allylamine) (PAA) and poly(vinyl sulfate) (PVS).
• Layer-by-layer sequential deposition of UOx and PAA to create enzyme multilayer films.
• Amperometric detection of hydrogen peroxide (H2O2) produced by the enzyme reaction at +0.6 V vs. Ag/AgCl.

Main Results:

• The sensor's response current increased with the number of UOx layers.
• Uric acid was detected in the concentration range of 10(-6)-10(-3) M, with selectivity over ascorbic acid.
• Optimal deposition conditions (pH, salt concentration) were identified for maximizing UOx deposition and sensor response.
• The sensor retained 60% of its original activity after 30 days.

Conclusions:

• Layer-by-layer assembly of UOx and polyelectrolyte multilayer films provides an effective strategy for developing sensitive and selective amperometric uric acid biosensors.
• The developed sensor shows promise for practical applications in uric acid monitoring.
• Further optimization of deposition parameters and long-term stability studies are warranted.