An electrochemiluminescence-based fibre optic biosensor for choline flow injection analysis.

Area of Science:

• Analytical Chemistry
• Biotechnology
• Biosensor Technology

Background:

• Choline detection is crucial in various biological and clinical applications.
• Existing choline detection methods often face limitations in sensitivity and stability.
• Development of efficient and stable biosensors is essential for accurate choline quantification.

Purpose of the Study:

• To develop a fiber optic biosensor for choline detection using luminol electrochemiluminescence (ECL).
• To immobilize choline oxidase (Chx) using different methods and evaluate their performance.
• To optimize reaction conditions for enhanced choline biosensor sensitivity and stability.

Main Methods:

• Fabrication of a fiber optic biosensor integrated with a flow injection analysis (FIA) system.
• Immobilization of choline oxidase (Chx) via covalent attachment or physical entrapment.
• Generation of ECL using a glassy carbon electrode and luminol.
• Optimization of buffer composition, pH, and flow rate for biosensor performance.

Main Results:

• The DEAE-PVA-Chx sensing layer achieved the lowest detection limit of 10 pmol for choline.
• The DEAE-PVA system demonstrated superior operational stability, allowing 160 repeated measurements.
• Optimized conditions included a 30 mM veronal buffer with 30 mM KCl and 1.5 mM MgCl2 at pH 9.

Conclusions:

• The developed fiber optic ECL biosensor provides a sensitive and stable platform for choline detection.
• The DEAE-PVA immobilization strategy offers significant advantages in terms of sensitivity and operational stability.
• This biosensor holds promise for practical applications in choline analysis.