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 nanoscale particles to diffract light of a color related to the glucose concentration. This glucose sensing material will be the sensing element of a contact lens, as well as an ocular insert designed for placement behind the lower eyelid. The patient will determine glucose concentration by viewing the color of the sensing material in a compact-mirrored device. This colorimetric sensing device contains a white light source, a mirror and a color chart. The observed color 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 inset-type devices which can be tested in phase II of this program in animals and humans
