Abstrakt
This work is aimed at development of new fluorescent labels based on silicon nanocrystals. Nanodiamonds and commercial CdSe quantum dots have been used as comparative materials.
Silicon nanocrystals are relatively small (1-4 nm) compared to other studied nanomaterials. They are prepared by electro-chemical etching and their surface can be activated by various molecules which strongly influences luminescence properties.
Luminescence quantum efficiency can be as high as 30 % and perfectly photostable even in biological environment. Si nanocrystals are biodegradable in a living organism within reasonable time scale and non-toxic.
We are able to detect luminescence of single nanocrystals, even inside living cells, with use of our micro-spectroscopy apparatus. Nanodiamonds have weak luminescence; they are toxic at higher dosages and very stable in living bodies (without available technique how to remove them).
Studied CdSe commercial quantum dots are strongly cytotoxic and their luminescence bleaches out under stronger excitation. In conclusion, Si nanocrystals are outstanding in all relevant parameters and they are suitable as novel fluorescent labels for application in biology, even for single molecule tracking in living cells.