This Phase I research and development program will develop novel, real-time, noninvasive (or minimally invasive) glucose colorimetric sensors for tear fluid. These sensors are based on new photonic crystal chemical sensing materials recently invented at the University of Pittsburgh. These photonic crystal sensors use arrays of nanosclae particles to diffract visible light. The wavelength of light diffracted and the color perceived visually can be used to determine the glucose concentration. This glucose sensing material will be utilized as the sensing element of a contact lens, as well as an ocular insert designed for use underneath the lower eyelid. The patients will determine their glucose concentration by utilizing the simple spectrometer device. The observed diffraction wavelength reports on the patient's tear fluid glucose concentration. Since the tear fluid glucose concentration tracks the blood glucose concentration, a tear fluid glucose measurement determines the blood glucose concentration. We will optimize the responsivity of these sensor materials and develop fabrication methods to incorporate the sensing material in contact lenses and ocular insert-type devices which will be tested in Phase II of this program in animals and humans. These minimally invasive tear fluid glucose sensors will revolutionize glycemic control for patients with diabetes mellitus. These devices will permit painless, continuous, inexpensive monitoring of glucose levels, which will dramatically increase patient glucose monitoring compliance and the long term health consequences of diabetes mellitus
