Molecular rectifiers with very high rectification ratio enabled by oxidative damage in double-stranded DNA

TL;DR

This study demonstrates that oxidatively damaged DNA can function as highly effective molecular diodes with rectification ratios up to 10^6, revealing new potential for DNA-based electronic devices.

Contribution

The paper introduces a novel method to create DNA-based molecular diodes with record-high rectification ratios by leveraging oxidative damage, specifically 8-Oxoguanine modifications.

Findings

Achieved rectification ratios up to 10^6 in DNA molecules.

Discovered negative differential resistance in oxidized DNA sequences.

Identified 8oxoG as a charge trap that protects genome integrity.

Abstract

In this work, we report a novel strategy to construct molecular diodes with a record tunable rectification ratio of as high as 10^6 using oxidatively damaged DNA molecules. Being exposed to several endogenous and exogenous events, DNA suffers constant oxidative damages leading to oxidation of guanine to 8-Oxoguanine (8oxoG). Here, we study the charge migration properties of native and oxidatively damaged DNA using a multiscale multiconfigurational methodology comprising of molecular dynamics, density functional theory and kinetic Monte Carlo simulations. We perform a comprehensive study to understand the effect of different concentrations and locations of 8oxoG in a dsDNA sequence on its CT properties and find tunable rectifier properties having potential applications in molecular electronics such as molecular switches and molecular rectifiers. We also discover the negative differential resistance properties of fully oxidized Drew-Dickerson sequence. The presence of 8oxoG guanine leads to the trapping of charge, thus operates as a charge sink, which reveals how oxidized guanine saves the rest of the genome from further oxidative damage.