NIR FRET Fluorophores for Use as an Implantable Glucose Biosensor

Abstract

Development of an in vivo optical sensor requires the utilization of Near Infra Red (NIR) fluorophores due to their ability to operate within the biological tissue window. Alexa Fluor 750 (AF750) and Alexa Fluor 680 (AF680) were examined as potential NIR fluorophores for an in vivo fluorescence resonance energy transfer (FRET) glucose biosensor. AF680 and AF750 found to be a FRET pair and percent energy transfer was calculated. Next, the tested dye pair was utilized in a competitive binding assay in order to detect glucose. Concanavalin A (Con A) and dextran have binding affinity, but in the presence of glucose, glucose displaces dextran due to its higher affinity to Con A than dextran. Finally, the percent signal transfer through porcine skin was examined. The results showed with approximately 4.0 mm porcine skin thickness, 1.98 % of the fluorescence was transmitted and captured by the detector.

Keywords

• FRET
• NIR
• Dextran
• Concanavalin A
• Glucose biosensor