A Polarity-Sensitive Far-Red Fluorescent Probe for Glucose Sensing through Skin

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Diabetes Technology

Background:

• Continuous glucose monitoring (CGM) is crucial for effective diabetes management.
• Existing glucose biosensors face challenges in sensitivity, stability, and subcutaneous implantation.
• Concanavalin A (ConA) offers a promising platform for glucose detection through reversible binding.

Purpose of the Study:

• To develop and optimize a novel glucose biosensor for subcutaneous implantation.
• To utilize solvatochromism and competitive binding for glucose detection.
• To evaluate the performance of different Cy5.5-labeled mannose molecules as competing ligands.

Main Methods:

• Development of a competitive binding glucose biosensor employing ConA and a fluorescent probe.
• Synthesis and comparison of three Cyanine 5.5 (Cy5.5)-labeled mannose molecules.
• Investigation of the biosensor's response to varying glucose concentrations (25-400 mg/dL) and its performance under different skin pigmentations.

Main Results:

• Cy5.5-mannotetraose exhibited optimal performance as the competing ligand.
• The developed biosensor accurately detected glucose in the physiological range (25-400 mg/dL).
• The biosensor demonstrated consistent and repeatable signals across various skin tones, indicating minimal interference from pigmentation.

Conclusions:

• The novel ConA-based fluorescent biosensor is suitable for subcutaneous glucose monitoring.
• The use of Cy5.5-labeled mannose enhances signal detection and skin penetration for implantable devices.
• This technology shows potential for improved diabetes management through reliable, real-time glucose tracking across diverse populations.