2. Project Goals: The project goals are to create a mechanically flexible, contact lens-based, affinity nanosensor to continuously monitor glucose concentrations in tears
3. Abstract:
3a. Nontechnical Abstract: Approximately 25.8 million people in the U.S. have diabetes, which is the seventh leading cause of death. Continuous glucose monitoring (CGM) involves repetitive measurements of physiological glucose concentration to allow close monitoring and timely correction of problematic blood sugar patterns of diabetes patients. CGM can significantly reduce the risk of diabetes-related complications, but existing CGM devices are not yet adequate because of limited stability, insufficient accuracy, slow responses, and invasiveness. This project aims to create a mechanically flexible, contact lens-based nanosensor to overcome these limitations. The nanosensor will exploit the nanomaterial graphene and measure glucose concentrations in tears via physical interactions of a synthetic polymer with glucose, thereby enabling stable and accurate CGM in a noninvasive, nonobstructive and convenient manner. With these capabilities, the nanosensor will potentially lead to improved care of patients with diabetes and other related disorders, and can be extended to the monitoring or detection of additional tear-borne analytes in healthcare. The nanosensor can also broadly impact other applications. For instance, in military applications, the device can potentially be used to enable health monitoring as well as drug and nutritional supplement delivery, thereby improving the protection of soldiers and enhancing their performance in the battlefield. In addition, the principal investigators will extend their current educational efforts in training graduate students and educating undergraduate students, including those from underrepresented groups, in an interdisciplinary research environment. The research team will also actively participate in strong educational outreach activities in the New York City and Columbia, SC, areas.
3b. Technical Abstract: The affinity nanosensor will use polymer-functionalized graphene to enable continuous monitoring of glucose in tears in the eye. The device will be constructed by an interdisciplinary approach, which, as a primary intellectual merit of the proposed research, combines graphene nanotechnology, synthetic polymer chemistry, and flexible micro-electro-mechanical systems. Graphene, a single, tightly packed layer of carbon atoms bonded together in a hexagonal honeycomb lattice, is emerging as a highly promising functional nanomaterial in chemical and biological sensors. Such sensors at present most commonly operate in solid- or gas-phase environments, and their use in liquid media is relatively limited. In particular, graphene has not yet been explored to enable affinity glucose sensing in physiological fluids. This research exploits the high surface-charge sensitivity, mechanical flexibility and optical transparency of graphene for glucose measurement in tears. The graphene will be functionalized with a synthetic, boronic acid-derivatized polymer and bonded on a mechanically flexible, contact lens-shaped substrate. By differential measurement of changes in the electric conductance of graphene due to specific affinity binding between the boronic acid moieties and glucose molecules, the device will allow specific, sensitive and rapid measurement of glucose concentration. In this design, the device will possess optimal miniaturization to attain a rapid time response, high sensitivity to effect improved glucose measurement accuracy, and mechanical flexibility to reduce adverse tissue-device interactions. With future integration of wireless telemetry, the nanosensor can enable stable and accurate continuous glucose monitoring in a noninvasive, nonobstructive and convenient manner.
