Characterization of Emergence of the Coulomb Blockade in a Pearl-Like DNA-AuNP Assembly

Due to its superior self-assembly properties and vast functionalization pos-sibilities DNA has long been one of the most promising candidates forfabrication of nanoscale electrical components using molecular buildingblocks. There exist already many demonstrations on optical devices based onorganizing metallic nanoparticles (NP) via DNA self-assembly, but despite thepromises only few DNA based electrical devices or studies have been realizedso far. Here we study the gold NP conjugated and metallized DNA TX-tile-structure, which we recently showed to exhibit the room temperature Coulombblockade, the pre-requisition for a single electron transistor. The properties ofthe obtained Coulomb blockade are further characterized via the differentialconductance measurements at temperatures ranging from 4.2 K to 10.2 K.The results show sharp blockade plateaus with varying threshold voltages,which yields further evidence of a gating effect by background charges. Thisstrongly indicates that the DNA-NP assembly functions as a single electrontransistor. Also, the additional growth of gold NPs and electrodes via chemicalgold deposition process, needed to achieve the Coulomb blockade, is studiedhere in more details, yielding more insight to the process, and thus helping torealize better control of it.