Amperometric biosensor for xanthine determination based on Fe3O4 nanoparticles.

Area of Science:

• Electrochemistry
• Biosensors
• Nanomaterials

Background:

• Xanthine detection is crucial for diagnosing certain metabolic disorders.
• Developing sensitive and selective biosensors is essential for accurate xanthine quantification.
• Carbon paste electrodes modified with nanomaterials offer enhanced electrochemical performance.

Purpose of the Study:

• To develop a novel amperometric xanthine biosensor.
• To utilize Fe3O4 nanoparticles for improved electrode properties.
• To enable sensitive and selective determination of xanthine.

Main Methods:

• Immobilization of xanthine oxidase (XO) onto Fe3O4 nanoparticles modified carbon paste.
• Electrochemical characterization using cyclic voltammetry and electrochemical impedance spectroscopy.
• Optimization of pH, nanoparticle loading, and enzyme loading.

Main Results:

• Fe3O4 nanoparticles enhanced the electroactive surface area and electron transfer.
• Optimal conditions determined for pH (6.0), nanoparticle loading (14.2%), and enzyme loading (0.6 Unit XO).
• The biosensor achieved sensitive xanthine detection (linear range: 7.4 × 10-7 to 7.5 × 10-5 mol L-1; detection limit: 2.0 × 10-7 mol L-1) at -0.20 V, minimizing interference.

Conclusions:

• The developed Fe3O4 nanoparticles modified carbon paste biosensor is effective for xanthine determination.
• The biosensor demonstrates high sensitivity and selectivity, suitable for practical applications.
• This approach offers a promising method for detecting xanthine in biological samples like urine.