Mixed ceria-based metal oxides biosensor for operation in oxygen restrictive environments

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Ceria and mixed ceria/titania composites possess unique catalytic, electrochemical, and oxygen storage properties.
• These properties are leveraged for advanced electrochemical enzyme biosensors.

Purpose of the Study:

• To fabricate a novel electrochemical enzyme biosensor using ceria and ceria/titania composites.
• To investigate the biosensor's performance in both oxygen-present and oxygen-free conditions.
• To develop a tyrosinase-based biosensor for detecting phenol and dopamine.

Main Methods:

• Fabrication of electrochemical enzyme biosensors using ceria and ceria/titania hybrid composites.
• Cyclic voltammetry to study enzymatic reactions with and without oxygen.
• Amperometric detection for quantifying phenol and dopamine.
• Optimization and characterization of biosensor parameters (response time, detection limit, sensitivity, kinetics).

Main Results:

• The biosensor demonstrated high sensitivity for phenol detection, with limits of detection in the nanomolar range (9.0 x 10(-9) M with oxygen, 5.6 x 10(-9) M without oxygen).
• Selective determination of dopamine was achieved with detection limits of 3.4 x 10(-8) M (with oxygen) and 4.2 x 10(-8) M (without oxygen).
• The materials facilitated operation in oxygen-free conditions, enhancing analytical performance.

Conclusions:

• The developed ceria-based biosensor offers improved sensitivity for oxidase enzyme sensors.
• The strategy allows for biosensor operation in oxygen-limited environments.
• This approach holds potential for developing other enzyme biosensors.