SERS Nanosensors for in Vivo Glucose Sensing
Abstract
The proposed research will introduce a technology that radically improves the management of diabetes. Diabetes is a chronic disease affecting about 24 million people in the U.S. and about 200 million people worldwide. While diabetes is not directly a deadly disease, it has dramatic implications on the health of patients (cardiovascular disease, stroke, chronic kidney failure, and others) and results in compromised quality of life and a shortened life expectancy. As such, it is listed by the Centers for Disease Control and Prevention (CDC) as among the 10 leading causes of death in the U.S., and it is recognized to have a very significant economic cost (~$176 billion per year (USA, 2012) reported by the CDC in 2014). Diabetes is a chronic disease dealing with the blood levels of glucose -- a small molecule that serves as an energy source. Unlike healthy subjects, diabetic patients cannot internally regulate their blood glucose levels through injections of insulin. As a consequence, they need to externally (1) monitor and (2) regulate these latter, several times a day. The monitoring aspect is painful and time-consuming, as patients need to prick their fingers and measure their blood glucose levels several times a day. Further, because monitoring is not performed continuously, an individual s glucose levels can depart significantly from normal levels, leading to increased stress on the body and faster onset of long-term disease, including poor circulation in the legs and feet. The overarching goal of the present proposal is to lighten the burden (physical and psychological) that daily glucose checks represent for patients and to improve their long-term health. Our objective is to fabricate very small and extremely sensitive sensors -- nanosensors -- that can continuously detect and measure glucose in living tissue over a long period of time (several months) without the need for drawing blood. This would represent a major advance for diabetic patients compared to the current continuous sensors available on the market, with a lifetime of one week. The second major advantage of the sensor we intend to develop is to directly detect glucose itself -- not the products of glucose transformation -- which require external reagents that add extra costs and steps, and which can respond to other molecules in the blood, including fructose, that leads to a false measurement. We are confident this audacious objective is within reach. Our two research teams have a long history of collaboration and have already developed two first-generation glucose sensors, including one tested in rats that demonstrated 17 days of action. The second sensor improved on the first in two critical aspects: (1) the design and development of sensors had improved sensitivity for very small glucose amounts to be detected and measured with great precision and (2) the sensors were modified with carefully designed molecules that capture glucose -- and only glucose -- and thus provide the most accurate readings in the shortest amount of time (less than two minutes). Based on this existing technical know-how, the two teams will collaborate to further develop the current sensors by focusing on biocompatibility -- that is, making the sensors bio-"friendly" and minimizing adverse effects from the body -- and ultimately bridge the gap between the laboratory and real-life patients. The roadmap for this research program is as follows: We will (1) make the existing sensors biocompatible and in parallel develop a novel sensor based on already biocompatible materials; (2) thoroughly characterize these sensors for optimal glucose detection in biological conditions (model); and (3) monitor glucose through the skin of small living animals (rats) for 3 months. Through an iterative development process, we will leverage the experience of the team and minimize the risks associated with this project. The resulting work will have important ramifications in diabete
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 31, 2017
- Source ID
- W81XWH1610375
Entities
People
- Richard P. Van Duyne
Organizations
- Northwestern University
- United States Army