In the present thesis, research work to tackle challenges such as large-scale integration, selectivity and low efficiency around different types of nanocarbon based sensors is performed. The findings of these studies are given in the form of peer-reviewed publications and conclusions with future recommendations proposed as a summary. The work focuses on three key sensors types, gas sensors, biosensors and photodetectors. The first key aspect is dielectrophoretic (DEP) deposition of nitrogen doped single-walled carbon nanotubes (N-SWCNTs) and it is used as a route to large-scale assembly of increased reactivity, and thus selectivity, gas sensors. Furthermore, suspended SWCNTs and few layer graphene (FLG) devices are fabricated through a novel process which results in increased surface area transducers and low resistance SWCNTs based devices. Moreover, biosensors face similar challenges to gas sensors with the addition that their selectivity needs to be engineered through the formation of a biomimetic interface due to the nature of the analytes they are destined to investigate. Non-covalent functionalization of graphene using self-assembled phospholipid membranes delivered in a controlled and precise manner by dip-pen nanolithography (DPN) was demonstrated together with a high-speed fabrication process of bioassays onto patterned CVD graphene using a parallel tips system. Lastly, for the case of photodetectors, a SWCNT – nanoplasmonic system is proposed as a solution to the major issue of low quantum efficiency in low dimensionality materials. First, the performance of various geometries and arrangements of Au nanoparticles is explored by transferring a micromechanically exfoliated graphene flake onto them and studying the Raman enhancement that arises due to uncoupled and coupled near-fields. An increase of graphene Raman signal of 103 was observed for the areas suspended between two closely spaced dimers as a result of strong near field coupling when the polarisation of the incident light is parallel to the nanostructures axis. A large-scale integration of SWCNTs positioned in between the dimers using DEP is performed as a demonstration of the scalability of the system.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:644522 |
| Date | January 2015 |
| Creators | Oikonomou, Antonios |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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