Not all fluorescent nanodiamonds are created equal

28 January 2019:

Hundreds of individual tiny fluorescent diamond particles have been imaged and characterized by CNBP researchers, reported in the journal ‘Particle & Particle Systems Characterization’.

Fluorescent nanodiamonds (FNDs) are vital to many emerging nanotechnological applications, from bioimaging and sensing to quantum nanophotonics.

The study identifies opportunities to improve the properties of single fluorescent nanodiamonds, to develop a better understanding of their underlying physical mechanisms and to advance current nanofabrication technologies.

Lead author on the paper is CNBP Associate Investigator Dr Philipp Reineck at RMIT University.

Journal: Particle & Particle Systems Characterization.

Publication title:  Not All Fluorescent Nanodiamonds Are Created Equal: A Comparative Study.

Authors: Philipp Reineck; Leevan Fremiot Trindade, Jan Havlik, Jan Stursa, Ashleigh Heffernan, Aaron Elbourne, Antony Orth, Marco Capelli, Petr Cigler, David A. Simpson, Brant C. Gibson.

Abstract: Fluorescent nanodiamonds (FNDs) are vital to many emerging nanotechnological applications, from bioimaging and sensing to quantum nanophotonics. Yet, understanding and engineering the properties of fluorescent defects in nanodiamonds remain challenging. The most comprehensive study to date is presented, of the optical and physical properties of five different nanodiamond samples, in which fluorescent nitrogen‐vacancy (NV) centers are created using different fabrication techniques. The FNDs’ fluorescence spectra, lifetime, and spin relaxation time (T1) are investigated via single‐particle confocal fluorescence microscopy and in ensemble measurements in solution (T1 excepted). Particle sizes and shapes are determined using scanning electron microscopy and correlated with the optical results. Statistical tests are used to explore correlations between the properties of individual particles and also analyze average results to directly compare different fabrication techniques. Spectral unmixing is used to quantify the relative NV charge‐state (NV− and NV0) contributions to the overall fluorescence. A strong variation is found and quantified in the properties of individual particles within all analyzed samples and significant differences between the different particle types. This study is an important contribution toward understanding the properties of NV centers in nanodiamonds. It motivates new approaches to the improved engineering of NV‐containing nanodiamonds for future applications.