Abstract

Monitoring glucose levels in biological samples is crucial to prevent complications arising from high blood glucose, such as heart-related issues, kidney problems, and vision loss. Traditional colorimetric glucose detection in urine relies on enzymatic reactions, offering a low-cost and non-invasive method for diabetes management. However, enzymes used in these assays are highly susceptible to environmental conditions, particularly elevated temperatures, which limit their transportation and storage.
In response to this challenge, this thesis presents a novel solution: the development of stable and portable enzyme-based tablet sensors. In this technique, glucose oxidase and horseradish peroxidase enzymes are encapsulated within a water-soluble dextran matrix, transforming them into solid tablets. This encapsulation enhances enzyme stability and practicality, making these sensors user-friendly. The enzymatic tablet-based sensor demonstrates remarkable capabilities, detecting glucose in urine samples within a rapid 5-minute timeframe. Utilizing 3,3',5,5'-tetramethylbenzidine (TMB) as the indicator, the tablet sensor exhibits impressive performance within the clinically relevant glucose concentration range of 0-6 mM, boasting a remarkable limit of detection at 0.013 mM. Furthermore, these enzyme tablets exhibit enhanced thermal stability, retaining their activity even at an elevated temperature of up to 60 ℃, surpassing the performance of solution-phase enzymes. This resilience under harsh conditions significantly expands the accessibility and application of glucose sensors, especially in resource-limited settings. The development of these tablet sensors represents a significant advancement in glucose monitoring technology, offering an effective and user-friendly solution for diabetes management.