Mohamed Serry
The American University in Cairo, Egypt
Title: Graphene-based composite biosensors for continuous glucose monitoring
Biography
Biography: Mohamed Serry
Abstract
Diabetic complications, especially cardiovascular disease and renal disease, make diabetes the seventh leading cause of death in the USA in 2007. Close monitoring and timely correction of elevated blood sugar can reduce the risk of diabetes-related complications. Portable glucometers, which measure blood glucose levels by finger pricks, may fail to detect rapid glucose changes. Continuous Glucose Monitoring (CGM) sensors using electrochemical detection are intended to address this, however, enzyme-catalyzed CGM have significant drawbacks, including (1) detection errors from irreversible consumption of glucose of the tissue, (2) drift over time, due to H2O2 production as a byproduct, affecting device accuracy, reliability, and longevity, and requiring repeated calibration (2-5 times/day), (3) need for frequent replacement (every 3-5 days), due to H2O2, and O2 mediators, (4) intermediate reactions that delay detection with possible false signals, due to interference with ascorbic and uric acids. Therefore, there is a dire need for non-enzymatic, mediator-free electrochemical glucose detectors which provide rapid response, better stability, and allow full implantation and wireless detection. In this work, we introduce non-enzymatic, mediator free glucose sensors by growing CVD graphene on a nanostructured platinum/silicon Schottky junction. Non-enzymatic detection is achieved by the adsorption of glucose molecules on the graphene surface, glucose OH− groups interact with O2 on the graphene surface. This interaction p-dopes the graphene layer, shifting the Dirac point to positive potential, thus varying the Schottky barrier’s height (SBH) and width, resulting in a detectable current change. The results indicated that the proposed sensor provided a highly sensitive, more facile method with good reproducibility for continuous glucose detection.