Modified insulator semiconductor electrode with functionalized nanoparticles for Proteus mirabilis bacteria biosensor...

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Nanotechnology

Background:

• Enzymatic sensors require enzyme purification, risking activity loss.
• Immobilizing bacteria offers a stable, adaptable biological sensing element.
• Urea biosensors are crucial for biomedicine, pharmacy, food, and environmental monitoring.

Purpose of the Study:

• To develop a stable and sensitive urea biosensor.
• To immobilize Proteus mirabilis bacteria onto insulator-semiconductor electrodes.
• To evaluate the biosensor's performance and linear response range.

Main Methods:

• Immobilization of Proteus mirabilis bacteria on functionalized Fe3O4 nanoparticles using polyelectrolytes (PAH/PSS), BSA, and glutaraldehyde.
• Utilizing insulator-semiconductor electrodes (Si/SiO2/Si3N4 and Si/SiO2).
• Assessing urease activity with ion ammonium selective electrodes (ISEs) and studying cell adhesion via contact angle measurements.

Main Results:

• A linear relationship was observed between flat band potential shift (ΔVFB) and urea concentration from 10⁻² M to 10⁻⁵ M.
• The immobilized bacteria demonstrated high operational stability under varying conditions.
• Successful immobilization of bacteria onto the functionalized electrode surface was confirmed.

Conclusions:

• The developed bacterial immobilization strategy provides a robust and sensitive platform for urea detection.
• This method enhances biosensor stability and adaptability for practical applications.
• The biosensor shows promise for use in diverse fields requiring urea monitoring.