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

TL;DR

This study investigates how DNA molecules deposited across metallic nanoparticle-embedded slits conduct electricity, revealing that metallic particles can facilitate charge transfer and induce superconductivity in DNA at low temperatures.

Contribution

It demonstrates that metallic nanoparticles within nanogaps enable charge transfer and superconductivity in DNA, offering insights into DNA's conductive properties and reconciling previous conflicting results.

Findings

DNA conduction occurs via interaction with Ga nanoparticles

Superconducting fluctuations observed at low temperatures

Metallic particles facilitate charge transfer to DNA

Abstract

We report in detail our experiments on the conduction of $\lambda$ 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 $\lambda$ 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.