Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Urea analysis is crucial in various fields, including clinical diagnostics and environmental monitoring.
• Development of sensitive, selective, and stable biosensors is essential for accurate urea detection.
• Graphene and polyaniline nanocomposites offer promising properties for electrochemical sensing applications.

Purpose of the Study:

• To develop an electrochemical biosensor for urea analysis using a sulfonated graphene/polyaniline nanocomposite.
• To characterize the structural properties of the developed nanocomposite.
• To evaluate the performance of the biosensor for urea detection, including its sensitivity, linear range, response time, and stability.

Main Methods:

• Electrochemical polymerization of aniline in the presence of sulfonated graphene oxide.
• Characterization of the nanocomposite using Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy.
• Immobilization of urease enzyme onto the nanocomposite film for urea detection.

Main Results:

• The sulfonated graphene/polyaniline nanocomposite was successfully synthesized and characterized.
• The developed biosensor exhibited a low detection limit (0.050 mM) and high sensitivity (0.85 μA·cm⁻²·mM⁻¹).
• The biosensor demonstrated a broad linear detection range (0.12–12.3 mM), rapid response time (approx. 5 seconds), and good stability (81% activity after 15 days).

Conclusions:

• The sulfonated graphene/polyaniline nanocomposite-based electrochemical biosensor is effective for urea analysis.
• The biosensor offers high sensitivity, rapid response, and good stability, making it suitable for practical applications.
• The ease of fabrication and cost-effectiveness suggest potential for developing advanced solid-state biosensors for urea detection.