Design and fabrication of a disposable, percutaneous glucose sensor

Sencils™ (sensory cilia) are chemical sensors that are minimally invasive, disposable and easily readable to make frequent measurements of various analytes in vivo over a period of 1-3 months. A percutaneous optical fiber permits precise, reliable photonic measurement of chemical reactions in a nano-engineered polymer matrix attached to the internal end of the fiber. The first Sencils sense interstitial glucose based on measurement of fluorescence resonance energy transfer (FRET) between fluorophores bound to betacyclodextrin and Concanavalin A (Con A) in a polyethylene glycol (PEG) matrix. In vitro experiments demonstrate a rapid and precise relationship between the ratio of the two fluorescent emissions and concentration of glucose in saline over the physiological range of 0-500mg/dl. Chronic implantation in pigs has demonstrated biocompatibility. The Sencil platform can be adapted to detect other analytes in interstitial fluids.