2D nanomaterials as efficient and reusable sensors
We study atomically thin nanomaterials as potential sensors using quantum mechanical modeling of molecular adsorption. A material similar to graphene but containing carbon and nitrogen in a two-to-one ratio (C2N) is very promising as a sensor for airborne molecular pollutants and molecules in biological fluids. For molecules in liquids, we have studied the measurement of sugar levels.
Diabetes mellitus is an incurable disease that causes elevated blood sugar levels. Therefore, measuring blood sugar levels is an integral part of diabetes care. The available standard self-tests use blood glucose sensors that rely on an expensive glucose oxidase enzyme for measurement while involving the painful process of finger pricking. Moreover, the enzymatic glucose sensors are poor with too low detection limits and they have stability issues with variations of temperatures, pH values and humidity. A better scenario for diabetes self-monitoring would be to use new cheap and stable glucose sensors, which are sensitive enough for glucose sensing that alternative body fluids such as tears, sweat or saliva can be used instead of blood.
Two-dimensional materials are ideal for sensor applications, which is attributed to their high surface-to-volume ratio. Experimentally synthesizedC2Nnanomaterial pieces have great potential for sensor applications due to the electron borrowing pair present on each N atom, resulting in strong localized dipole moments that interact with molecules on their surface. In our work we investigate the potential ofC2Nfor the detection of sugar molecules (glucose, fructose and xylose) by using first principle calculations that include van der Waals interactions to determine how the sugars adsorb on the sensor surface and non-equilibrium Green's function methods to simulate the electrical response of the material due to adsorption. The project was funded by the Kempe Foundations, the Knut and Alice Wallenberg Foundation, and Interreg Nord, and is a collaboration between Luleå University of Technology (Sweden), Hindustan Institute of Technology and Science (India), Khalifa University (United Arab Emirates), Uppsala University (Sweden), and the University of Queensland (Australia).C2Nis not consumed and is not destroyed by use because the molecules are strongly physically bound (not chemically bound) due to the dipole moments of the nitrogen species. In addition, the molecular bond strengths are small enough that they can be removed, makingC2Nan ideal material for reuse after cleaning. Our results will pave the way for the development of efficient sensors for blood glucose detection.
Publications:
- Two-Dimensional Nitrogenated Holey Graphene (C2N) Monolayer Based Glucose Sensor for Diabetes Mellitus
- Sensing of volatile organic compounds on two-dimensional nitrogenated holey graphene, graphdiyne, and their heterostructure
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