[mcmancini]

What's the fluorescence emission mechanism, defect sites in the crystal lattice? What's the QY? What's the absorption spectrum look like, especially in the NIR range? If we were exciting these particles at 785nm, what would the emission spectrum look like (peak and FWHM)? Is the YC startup focused on the nanocrystals themselves, or on imaging agents including a targeting ligand?

Sorry for the basic questions, I no longer have journal access :( and this sounds neat :)

P.S., oh, and do they blink?

[Bikanta]

I'm happy to answer these technical questions. It's nice to share that info as that is what makes them so valuable. The fluorescence comes from nitrogen-vacancy centers. Here is a link showing the excitation and emissions spectrum. http://upload.wikimedia.org/wikipedia/commons/8/85/NVple.JPG

The Stokes shift, as you can see is very large. The quantum yield is 1 and they don't blink. We are initially focusing on stabilized nanodiamonds with various chemical groups put on the surface to have them ready for further conjugation. Email us at [e-mail] and I can have a further conversation with you if you would like.

[mcmancini]

For in vivo studies, and even possible human studies, have you given any thought for how you will do PK/BD on these? I'm having trouble imagining how you'll be able to detect these non-optically, unless you had some made of heavy isotopes for ICP/MS.

Continuing with the human studies thought, are these particles seeing RES uptake? I assume, based on the high QY, that these the emission centers for these particles are protected by a thick shell and/or corona. General handwaving from the FDA was that they were as concerned with particles persisting as with elemental toxicity. Is there a predicted degradation pathway for these particles?

Can these particles be made with a hydrodynamic radius, including corona, <8nm? Is it possible to dope them to get better NIR emission?

Unrelated to technical stuff: I thought that a YC thing was that you had to move to San Diego for a few months. That doesn't seem all that conducive to wet lab work, in fact, it seems like a non-starter. Is that still a requirement for the bio-related startups? If so, how how disruptive is it?

Thanks for the answers!