3 research outputs found
Nanodiamond emulsions for enhanced quantum sensing and click-chemistry conjugation
Nanodiamonds containing nitrogen-vacancy (NV) centers can serve as colloidal
quantum sensors of local fields in biological and chemical environments.
However, nanodiamond surfaces are challenging to modify without degrading their
colloidal stability or the NV center's optical and spin properties. Here, we
report a simple and general method to coat nanodiamonds with a thin emulsion
layer that preserves their quantum features, enhances their colloidal
stability, and provides functional groups for subsequent crosslinking and
click-chemistry conjugation reactions. To demonstrate this technique, we
decorate the nanodiamonds with combinations of carboxyl- and azide-terminated
amphiphiles that enable conjugation using two different strategies. We study
the effect of the emulsion layer on the NV center's spin lifetime, and we
quantify the nanodiamonds' chemical sensitivity to paramagnetic ions using
relaxometry. This general approach to nanodiamond surface
functionalization will enable advances in quantum nanomedicine and biological
sensing.Comment: 52 pages, 42 figures (main text plus supplementary information