Spin-blockade effect and coherent control of DNA-damage by free radicals: a proposal on bio-spintronics

TL;DR

This paper proposes a bio-spintronics approach where coherent control of free radicals' spins can prevent DNA damage by creating a spin-blockade, with potential applications in protecting genetic material.

Contribution

It introduces a model for controlling DNA damage via spin-triplet states and demonstrates the spin-blockade effect through molecular simulations, a novel approach in bio-spintronics.

Findings

Efficient population of DNA's spin-triplet state achieved.

Spin-blockade can prevent hydrogen abstraction and DNA damage.

Simulation confirms the feasibility of spin-controlled DNA protection.

Abstract

Coherent control of OH-free radicals interacting with the spin-triplet state of a DNA molecule is investigated. A model Hamiltonian for molecular spin singlet-triplet resonance is developed. We illustrate that the spin-triplet state in DNA molecules can be efficiently populated, as the spin-injection rate can be tuned to be orders of magnitudes greater than the decay rate due to small spin-orbit coupling in organic molecules. Owing to the nano-second life-time of OH free radicals, a non-equilibrium free energy barrier induced by the injected spin triplet state that lasts approximately longer than one-micro second in room temperature can efficiently block the initial Hydrogen abstraction and DNA damage. For a direct demonstration of the spin-blockade effect, a molecular simulation based on an {\em ab-initio} Car-Parrinello molecular dynamics is deployed.