Scheme for detection of single-molecule radical pair reaction using spin in diamond

TL;DR

This paper proposes a theoretical scheme to detect single-molecule radical pair reactions using nitrogen-vacancy centers in diamond, enabling magnetic field effects to be observed at the individual molecule level.

Contribution

It introduces a novel method for single-molecule detection of radical pair reactions using diamond spin sensors, advancing biological and chemical magnetic sensing.

Findings

Theoretically demonstrates detection of radical pair charge recombination rates.

Shows potential to observe geomagnetic field effects on single molecules.

Proposes a hybrid chemical compass model for magnetic sensing.

Abstract

The radical pair reaction underlies the magnetic field sensitivity of chemical reactions and is suggested to play an important role in both chemistry and biology. Current experimental evidence is based on ensemble measurements, however, the ability to probe the radical pair reaction at the single molecule level would provide valuable information concerning its role in important biological processes. Here, we propose a scheme to detect the charge recombination rate in a radical pair reaction under ambient conditions by using single nitrogen-vacancy center spin in diamond. We demonstrate theoretically that it is possible to detect the effect of the geomagnetic field on the radical pair reaction and propose the present scheme as a possible hybrid model chemical compass.