Distance measurements between 5 nanometer diamonds - single particle magnetic resonance or optical super-resolution imaging?

• Published in: Nanoscale advances 2023-02, Vol.5 (5), p.1345-1355
• Main Authors: Pinotsi, Dorothea, Tian, Rui, Anand, Pratyush, Miyanishi, Koichiro, Boss, Jens M, Chang, Kevin Kai, Welter, Pol, So, Frederick T.-K, Terada, Daiki, Igarashi, Ryuji, Shirakawa, Masahiro, Degen, Christian L, Segawa, Takuya F
• Format: Article
• Language: English
• Subjects: Chemistry
• ISSN: 2516-0230; 2516-0230
• DOI: 10.1039/d2na00815g

5 nanometer sized detonation nanodiamonds (DNDs) are studied as potential single-particle labels for distance measurements in biomolecules. Nitrogen-vacancy (NV) defects in the crystal lattice can be addressed through their fluorescence and optically-detected magnetic resonance (ODMR) of a single particle can be recorded. To achieve single-particle distance measurements, we propose two complementary approaches based on spin-spin coupling or optical super-resolution imaging. As a first approach, we try to measure the mutual magnetic dipole-dipole coupling between two NV centers in close DNDs using a pulse ODMR sequence (DEER). The electron spin coherence time, a key parameter to reach long distance DEER measurements, was prolonged using dynamical decoupling reaching T 2,DD 20 μs, extending the Hahn echo decay time T 2 by one order of magnitude. Nevertheless, an inter-particle NV-NV dipole coupling could not be measured. As a second approach, we successfully localize the NV centers in DNDs using STORM super-resolution imaging, achieving a localization precision of down to 15 nm, enabling optical nanometer-scale single-particle distance measurements. 5 nanometer sized detonation nanodiamonds (DNDs) are studied as potential single-particle labels for distance measurements in biomolecules.