Magnetically Modulated Fluorescence of Nitrogen-Vacancy Centers in Nanodiamonds for Ultrasensitive Biomedical Analysis
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2021-04-29 |
| Journal | Analytical Chemistry |
| Authors | Yuen Yung Hui, Oliver J. Chen, HsināHung Lin, Yu-Kai Su, Katherine Y. Chen |
| Institutions | National Taiwan Normal University, National Taiwan University of Science and Technology |
| Citations | 41 |
Abstract
Section titled āAbstractāThe negatively charged nitrogen-vacancy center in fluorescent nanodiamonds (FNDs) is a point defect with unique magneto-optical properties. It emits far-red fluorescence at ā¼700 nm, and its intensity can be magnetically modulated with a depth of more than 10% at a field strength of 30 mT. We have closely examined this property and illustrated its practical use in biomedicine by applying a periodic, time-varying magnetic field to FNDs deposited on a surface or dispersed in a solution with a lock-in detection method. We achieved selective and sensitive detection of 100 nm FNDs on a nitrocellulose membrane at a particle density of 0.04 ng/mm<sup>2</sup> (or ā¼2 Ć 10<sup>4</sup> particles/mm<sup>2</sup>) and in an aqueous solution with a particle concentration of 1 ng/mL (or ā¼1 fM) in 10 s as the detection limits. The utility and versatility of the technique were demonstrated with an application to background-free detection of FNDs as reporters for FND-based lateral flow immunoassays as well as selective quantification of FNDs in tissue digests for in vivo studies.