A Urea Potentiometric Biosensor Based on a Thiophene Copolymer.

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Potentiometric enzyme biosensors offer a convenient method for urea quantification.
• Monitoring urea levels is crucial for industrial processes and medical diagnostics (diabetes, kidney, liver conditions).

Purpose of the Study:

• To synthesize and characterize a novel copolymer, poly(3-hexylthiophene-co-3-thiopheneacetic acid) (P(3HT-co-3TAA)).
• To develop a potentiometric enzyme biosensor by immobilizing urease (Urs) onto P(3HT-co-3TAA) modified electrodes for urea detection.

Main Methods:

• Chemical synthesis and characterization of P(3HT-co-3TAA).
• Spin-coating of the copolymer onto indium tin oxide (ITO) glass electrodes.
• Covalent immobilization of urease (Urs) using carbodiimide coupling.
• Electrochemical analysis (cyclic voltammetry) and spectrophotometry to assess sensor performance and enzyme activity.

Main Results:

• The modified Urs/P(3HT-co-3TAA)/ITO electrode demonstrated electrochemical stability.
• Enzyme activity was successfully confirmed after immobilization.
• The biosensor exhibited a quasi-Nernstian potentiometric response for urea detection up to approximately 5 mM.
• Response time showed a half-time of less than 1 minute, with full equilibration in 10 minutes.

Conclusions:

• The developed enzyme biosensor based on P(3HT-co-3TAA) is effective for potentiometric determination of urea concentrations.
• This biosensor shows potential for applications in industrial monitoring and clinical diagnostics requiring urea level assessment.