Institute of Chemistry and Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, 91904 Israel
Charge transport through molecular structures is interesting both scientifically and technologically. To date, DNA is the only type of polymer that transports significant currents over distances of more than a few nanometers in individual molecules. Nevertheless and in spite of large efforts to elucidate the charge transport mechanism through DNA a satisfying characterization and mechanistic description has not been provided yet. For molecular electronics, DNA derivatives are by far more promising than native DNA due to their improved charge-transport properties. In recent years we have invested great efforts to address the above issues. Measuring the charge transport in DNA was elusive due to great technical difficulties leading to various results. We recently devised an experiment in which doublestranded DNA is well positioned between metal electrodes. Electrical measurements give surprisingly high currents over 100 base-pairs (~30 nm) elevated from the surface. The temperature dependence indicates backbone-related band-like transport.
In collaboration with the Kotlyar group, we were also able to synthesize and measure long (hundreds of nanometers) DNA–based derivatives that transport significant currents when deposited on hard substrates. Among the molecules, metal containing DNA, which is true metal-organic hybrid, a smooth and thin metal coated DNA and G-quadruplex DNA. Step by step we improve the synthesized constructs and the measurement methods of single DNA-based molecules. I will present new and surprising results on dsDNA molecules. I will present new DNA-based molecules and report on our measurements of their properties.
 “Direct measurement of electrical transport through DNA molecules”, Danny Porath, Alexey Bezryadin, Simon de Vries and Cees Dekker, Nature 403, 635 (2000).
 “Long Monomolecular G4-DNA Nanowires”, Alexander Kotlyar, Nataly Borovok, Tatiana Molotsky, Hezy Cohen, Errez Shapir and Danny Porath, Advanced Materials 17, 1901 (2005).
 “Electronic structure of single DNA molecules resolved by transverse scanning tunneling spectroscopy”, Errez Shapir et al., Nature Materials 7, 68 (2008).
 “Long-range charge transport in single G4-DNA molecules”, Gideon I. Livshits et. al., Nature Nanotechnology 9, 1040 (2014).
 “Synthesis and Properties of Novel Silver containing DNA molecules”, Gennady Eidelshtein et. al., Advanced Materials 28, 4839 (2016).
 “Highly conductive thin uniform gold-coated DNA nanowires”, Avigail Stern et. al., Advanced Materials 30, 1800433 (2018).
 “Advances in Synthesis and Measurement of Charge Transport in DNA-Based Derivatives”. R. Zhuravel, A. Stern, N. Fardian-Melamed, G. Eidelshtein, L. Katrivas, D. Rotem, A. Kotlyar and D. Porath, Advanced Materials 30, 1706984 (2018).
 “Scanning Tunneling Microscopy and Spectroscopy of Novel Silver-Containing DNA Molecules”, Natalie Fardian-Melamed, Gennady Eidelstein, Dvir Rotem, Alexander Kotlyar and Danny Porath, Advanced Materials, Article Number: 1902816 (2019).
 “Backbone Charge Transport in Double Stranded DNA”, Roman Zhuravel et. Al., Nature Nanotechnology 9, 836 (2020)