Graphene-based Nanostructures and DNA-based Biomolecule Sensors

For the past forty years, the entire electronics industry has been pushing the boundaries of innovation in order to make devices with higher speed, smaller size and increased complexity while at the same time maintaining low power consumption and low cost. After the first appearance of CNT in 1990 carbon has emerged as a front-runner underlying carbon-based nanotechnology. Carbon has various crystalline allotropes such as diamond, graphite, graphene, nanotubes and Buckminsterfullerenes. Since the discovery of the technique to produce graphene flakes called mechanical exfoliation in 2004, graphene has been claimed as the saviour of Moore's law. Graphene research has been mostly focused on transistors and thin film applications, but the interest in different applications of graphene is growing rapidly. Of all of the suggested applications of graphene, the use of graphene to make graphene-based field effect transistor seems the one most closest to emerge. This research work contains three main parts. The first part is to investigate the electrical conductivity and dielectric properties of PMMA/Graphene Nanoplatelet composites with an emphasis on the percolation threshold. The second part is the study of a graphene-based FET structure including modelling the FET characteristics based on device theory calculation and simulation, and utilizing Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy to verify active molecular components inside synthesized nanostructures. The third part is the sensor experiment part, which includes design, fabrication and testing of two biomolecular sensors using optical photolumescence measurements and graphene-based electrochemical measurements, respectively.