Diamond surface engineering for molecular sensing with nitrogen-vacancy centers

TL;DR

This paper reviews how diamond surface engineering enhances nitrogen-vacancy centers for quantum sensing, focusing on surface properties, chemical attachment, and potential applications in single-molecule detection.

Contribution

It provides a comprehensive survey of diamond surface science and NV-center physics, highlighting strategies to improve sensor stability and enable chemical functionalization for molecular sensing.

Findings

Surface properties influence NV center stability and coherence.

Methods for covalent bonding of molecules to diamond are discussed.

Potential for single-molecule chemical sensing with NV centers.

Abstract

Quantum sensing using optically addressable atomic-scale defects, such as the nitrogen--vacancy (NV) center in diamond, provides new opportunities for sensitive and highly localized characterization of chemical functionality. Notably, near-surface defects facilitate detection of the minute magnetic fields generated by nuclear or electron spins outside of the diamond crystal, such as those in chemisorbed and physisorbed molecules. However, the promise of NV centers is hindered by a severe degradation of critical sensor properties, namely charge stability and spin coherence, near surfaces (< ca. 10 nm deep). Moreover, applications in the chemical sciences require methods for covalent bonding of target molecules to diamond with robust control over density, orientation, and binding configuration. This forward-looking Review provides a survey of the rapidly converging fields of diamond surface science and NV-center physics, highlighting their combined potential for quantum sensing of molecules. We outline the diamond surface properties that are advantageous for NV-sensing applications, and discuss strategies to mitigate deleterious effects while simultaneously providing avenues for chemical attachment. Finally, we present an outlook on emerging applications in which the unprecedented sensitivity and spatial resolution of NV-based sensing could provide unique insight into chemically functionalized surfaces at the single-molecule level.