Urea biosensor based on PANi(urease)-Nafion/Au composite electrode

Area of Science:

• Electrochemistry
• Materials Science
• Biosensors

Background:

• Polyaniline (PANi)-Nafion composite films offer unique electrochemical properties.
• Developing sensitive and selective biosensors for urea detection is crucial for various applications.

Purpose of the Study:

• To prepare and characterize a PANi-Nafion composite film on a ceramic plate using cyclic voltammetry (CV).
• To immobilize urease onto the composite film for urea detection.
• To evaluate the performance of the developed urea sensor.

Main Methods:

• Preparation of PANi-Nafion composite film via CV with varying cycle numbers.
• Electrochemical characterization of the composite electrode.
• Immobilization of urease using electrochemical and casting methods.
• Detection of urea concentration in buffer solutions.

Main Results:

• The composite electrode prepared with 5 CV cycles showed the highest cathodic peak current in NH4Cl buffer.
• Cathodic peak current decreased with increasing CV cycles.
• The casting immobilization method yielded higher sensitivity compared to electrochemical immobilization.
• The urea sensor achieved a sensitivity of 0.7 µA (mg dL⁻¹)⁻¹cm⁻² and a detection limit of 0.3 mg dL⁻¹.

Conclusions:

• The PANi-Nafion composite film prepared by CV is a promising platform for biosensor development.
• Urease immobilization via casting enhances sensor performance.
• The developed urea sensor exhibits excellent sensitivity and a low detection limit.