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

该项目的目标是开发一种新的技术来测量基于DNA的单个分子聚集体的传输特性，该技术依赖于单壁碳纳米管作为接触引线。我们将使用电子显微镜中的电子束将纳米GaP切割成SiN膜，并在其上沉积一个SWNT。由此得到的一对单壁碳纳米管纳米接触将用不同长度的基于二亚胺的自组装DNA聚集体连接起来。这样的聚集体可以研究电荷通过长度明确的DNA链的传输。二酰亚胺分子作为(1)锚基将DNA连接到碳纳米管引线上，以及(2)作为电子通过DNA链跳跃的中间电荷岛。通过这种方法，可以研究DNA纳米聚集体的电导。与天然DNA相比，由于二酰亚胺发色团作为人工电荷岛的存在，预计导电性将得到改善，其中电子传递通过跳跃过程进行。接触形成将在液体环境中进行现场监测，而测量将在不同的液体环境和真空中进行。后者还可以用来研究低温输运性质。由于得到的单壁碳纳米管导线尺寸很小，分子的电荷状态可以通过附近的栅电极来控制。

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.