Long range electronic transport in DNA molecules deposited across a disconnected array of metallic nanoparticles

Abstract

We report in detail our experiments on the conduction of λ DNA molecules over a wide range of temperature deposited across slits in a few nanometers thick platinum film. These insulating slits were fabricated using focused ion beam etching and characterized extensively using near field and electron microscopy. This characterization revealed the presence of metallic Ga nanoparticles inside the slits, as a result of the ion etching. After deposition of λ DNA molecules, using a protocol that we describe in detail, some of the slits became conducting and exhibited superconducting fluctuations at low temperatures. We argue that the observed conduction was due to transport along DNA molecules, that interacted with the Ga nanoparticles present in the slit. At low temperatures when Ga becomes superconducting, induced superconductivity could therefore be observed. These results indicate that minute metallic particles can easily transfer charge carriers to attached DNA molecules and provide a possible reconciliation between apparently contradictory previous experimental results concerning the length over which DNA molecules can conduct electricity.

Controlling the Cassie-to-Wenzel Transition: an Easy Route towards the Realization of Tridimensional Arrays of Biological Objects

“…The fabrication of large ordered DNA arrays has been proposed as a promising strategy to perform highly automated analysis in the next-generation DNA chips [26]. Moreover thanks to its high aspect ratio, DNA is also an attractive candidate for the realization of highly aligned 1D nanostructure, showing the potential to address many challenges in electronics [27][28][29]. To this purpose, the precise controlling over the DNA positioning in the three directions of the space could help the integration of functional DNA filament into devices, since the integration process usually starts from the fabrication of metallic electrodes followed by the alignment of DNA above the electrodes.…”

Self-assembling of large ordered DNA arrays using superhydrophobic patterned surfaces

“…In this context, many experiments have been designed to probe the electronic transport properties of DNA molecules. Unfortunately, as highlighted in the recent work of Chepelianskii and co-workers [7], most of these attempts have led to controversial results mainly because of the interaction between the DNA and the substrate. This problem can be easily overcome by suspending DNA filaments between adjacent pillars as described here.…”

“…Beside DNA chips, practical interest in patterning DNA is also related to its self-assembly properties which allow one to obtain ad hoc shaped DNA superstructures with a bottom-up approach [3][4][5]. Thanks to its high aspect ratio, DNA is also an attractive candidate for the realization of highly aligned 1D nanostructures showing the potential to address challenges in electronics [6,7] and in magnetic [8] and chemical sensing [9]. For these purposes, the development of novel strategies for the precise positioning of DNA molecules in highly ordered structures is of paramount importance.…”

Quantum effects and magnetism in the spatially distributed DNA molecules

“…At the same time, "living" molecules which keep their native thickness are conducting up to very low temperature, although demonstrating a nonohmic behavior characteristic of a 1D conductor with repulsive electron-electron interactions. Long-range transport in DNA molecules can be achieved through interaction with a disconnected array of metallic Ga nanoparticles, and even induced superconductivity could be observed [21].…”