Disposable percutaneous glucose sensor

Sencilstrade (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 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 0-500 mg/dl. Chronic implantation in pigs has demonstrated biocompatibility. The materials and fabrication methods to produce Sencil implants are robust and inexpensive. Systematic nano-engineering of binding affinities, fluorophore attachment, reactant entrapment and matrix structure provides the key to a wide range of clinical applications