Benchtop Fluorination of Fluorescent Nanodiamonds on a Preparative Scale - Toward Unusually Hydrophilic Bright Particles
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-05-02 |
| Journal | Advanced Functional Materials |
| Authors | Jan HavlĂk, Helena RaabovĂĄ, Michal Gulka, VladimĂra PetrĂĄkovĂĄ, Marie KreÄmarovĂĄ |
| Institutions | Czech Academy of Sciences, Institute of Physics, University of Chemistry and Technology, Prague |
| Citations | 45 |
Abstract
Section titled âAbstractâFluorination of diamonds modulates their optical and electromagnetic properties and creates surfaces with increased hydrophobicity. In addition, fluorination of diamonds and nanodiamonds has been recently shown to stabilize fluorescent nitrogenâvacancy centers, which can serve as extremely sensitive single atomic defects in a vast range of sensing applications from quantum physics to highâresolution biological imaging. Traditionally, fluorination of carbon nanomaterials has been achieved using harsh and complex experimental conditions, creating hydrophobic interfaces with difficult dispersibility in aqueous environments. Here, a mild benchtop approach to nanodiamond fluorination is described using selective Ag + âcatalyzed radical substitution of surface carboxyls for fluorine. In contrast to other approaches, this highâyielding procedure does not etch diamond carbons and produces a highly hydrophilic interface with mixed CâF and CâOH termination. This dual functionalization of nanodiamonds suppresses detrimental hydrophobic interactions that would lead to colloidal destabilization of nanodiamonds. It is also demonstrated that even a relatively low surface density of fluorine contributes to stabilization of negatively charged nitrogenâvacancy centers and boosts their fluorescence. The simultaneous control of the surface hydrophilicity and the fluorescence of nitrogenâvacancy centers is an important issue enabling direct application of fluorescent nanodiamonds as nanosensors for quantum optical and magnetometry measurements operated in biological environment.