Positionally precise functionalization of shallow luminescent centers through Forster Resonant Energy Transfer (FRET) driven surface photochemistry

TL;DR

This paper introduces a high-precision, scalable surface functionalization method for shallow luminescent centers like NV centers in diamond, using FRET-driven surface photochemistry to enhance chemical sensing capabilities.

Contribution

It demonstrates a novel FRET-based surface functionalization technique that achieves positionally precise, scalable attachment of sensing groups near luminescent centers with quantifiable uncertainty.

Findings

Functionalization position uncertainty equals NV center deposition depth.

FRET efficiency depends on deposition depth and acceptor density.

Probability distribution of energy gaps enables single-molecule detection estimates.

Abstract

Paramagnetic luminescent impurities in solids such as Nitrogen-Vacancy (NV) centers in diamond represent a promising and versatile platform for the development of a wide range of chemical and biological sensors. This goal can be accomplished by the placement of chemically active, spin (electron or nuclear) labeled moiety on the surface in the close vicinity of a shallow single paramagnetic center. In this paper, we demonstrate that the Forster Resonant Excitation Transfer driven process where luminescent center plays a role of excitation donor can accomplish such a goal with high chemical efficiency, positionally precise and a scalable manner. We obtain the probability distribution function of the sensing group position relative to the luminescent center (NV center) and demonstrate that the functionalization position uncertainty is equal to the luminescent center deposition depth. The efficiency of the FRET process is analyzed as a function of the luminescent center deposition depth and the density of the excitation acceptor sites. Employing the geometric information of the surface-functionalized sensing groups, we obtain the probability distribution function of the energy gap in the spectrum of a spin-based detection system. This information allows us to estimate the single-molecule detection capabilities of the proposed system.