Colorimetric Glucose Biosensor Based on Chitosan Films and Its Application for Glucose Detection in Beverages Using a...

Area of Science:

• Biomaterials Science
• Analytical Chemistry
• Food Science

Background:

• Biosensors are increasingly vital for food and beverage quality control due to their sensitivity, specificity, and speed.
• Colorimetric biosensors integrated with smartphone applications offer accessible, real-time analyte detection.
• Chitosan (CS) and deep eutectic solvents (DES) provide a promising matrix for enzyme immobilization.

Purpose of the Study:

• To develop and optimize chitosan films immobilized with glucose oxidase (GOx) for glucose detection.
• To investigate the influence of pH and temperature on enzyme activity within the films.
• To evaluate the stability, specificity, and analytical performance of the developed biosensor films.

Main Methods:

• Preparation of chitosan (CS) films using a choline chloride/urea/glycerol (ChCl:U:Gly) deep eutectic solvent.
• Immobilization of glucose oxidase (GOx) onto CS films using glutaraldehyde (GA).
• Optimization of GOx concentration and DES content, followed by characterization of film properties and enzymatic activity.

Main Results:

• Optimized CS/GOx films demonstrated high accuracy, specificity to glucose, and stability over 4 weeks at 4 °C.
• The immobilized GOx retained significant activity across tested pH and temperature conditions.
• The biosensor films exhibited a linear response range of 0.1-0.8 mM with a limit of detection (LOD) of 33 μM.

Conclusions:

• The developed chitosan/glucose oxidase films are stable, reusable, and highly specific for glucose detection.
• The biosensor's compatibility with smartphone color recognition applications enables practical use in food and beverage quality assessment.
• This technology offers a cost-effective and efficient method for on-site glucose concentration estimation.