Solution-Processed Formation of DNA-Origami-Supported Polyoxometalate Multi-Level Switches with Countercation-Controlled Conductance Tunability

Wereport a chemically programmed design and the switching characteristicsof a functional metal-DNA-origami-polyoxometalate (POM)material obtained from the solution-processed assembling of biocompatiblemolecular precursors. The DNA origami is immobilized on the gold surfacevia thiolate groups and acts as a carrier (ad-layer) structure, ensuringthe spatially controlled hybridization of the pre-defined six-helixbundle (6HB) positions with DNA-augmented, tris(alkoxo)-ligated Lindqvist-typepolyoxovanadate (POV6) units. The DNA-confined POV6 units accept electronsin a stepwise fashion, allowing for a multi-logic function, whichwe directly probe using scanning tunneling electron microscopy andspectroscopy. Electron acceptance and injection into the originallynon-conducting DNA structure and the subsequent release to the goldsubstrate depend upon the potential at the nanoscale tip and the oxidationstate of POV6, as well as on the mechanism of action of POV6 countercations.By combining experiment and theory, we show that the bio-hybrid heterojunctionhas far-reaching potential to create a chemically controlled POM-basednano-environment with synaptic behavior.

Automated summary

We present a chemically programmed design and switching characteristics of a functional metal-DNA-origami-polyoxometalate (POM) material synthesized through solution-processing. The DNA origami acts as a carrier structure, controlling the hybridization of six-helix bundle (6HB) positions with DNA-augmented POV6 units on a gold surface. The electron acceptance and injection into the non-conducting DNA structure and release to the gold substrate depend on the potential at the nanoscale tip and the oxidation state of POV6.