Charge transport through individual perylene-bisimide DNA aggregates using single-walled carbon nanotubes as contact leads

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The goal of this project is the development of novel technique to measure the transport properties of individual DNA-based molecular aggregates relying on single walled carbon nanotubes (SWNTs) as contact leads. We shall use the electron beam in a transmission electron microscope to cut nanogaps into a SiN-membrane and a SWNT deposited on it. The resulting pair of SWNT nano-contacts will be bridged with self-assembled perylene bisimide-based DNA-aggregates of different lengths. Such aggregates allow to study the charge transport through DNA-strands of well defined length. The perylene-bisimide molecules act as (1) anchor groups for the attachment of the DNA to the CNT-leads and (2) as intermediate charge islands for the hopping of electrons via the DNA strands. In this way, the conductance of DNA-nanoaggregates can be studied. It is expected that the conductivity is improved compared to the natural DNA due to the presence of the perylene bisimide chromophores as artificial chargable islands, between which electron transport occurs via hopping processes. The contact formation will be monitored in-situ in liquid environment, while the measurements will be performed both in different liquid environments and in vacuum. The latter also allows to study the low-temperature transport properties. Because of the small dimensions of the resulting SWNT leads, the charge state of the molecules can be controlled by means of nearby gate electrodes.