Who are you?

I am Alexander Demchenko, a scientist residing and working in Ukraine. My field of interest is broad, between photophysics and biophysics, between photochemistry and biochemistry, focused on development and application of new fluorescence methods.

What prompted you to pursue this field of research?

For a long time I used tryptophan fluorescence as the method to gain information about structure and dynamics, but it was limited to peptides and proteins. With the application of fluorescence dyes, the possibilities became much broader and it became possible to obtain important information on biological membranes. We developed very sensitive dyes, dramatically shifting the colour of their emission. Now I have moved to new types of reporters – fluorescent nanoparticles – which have exciting new possibilities.

What is this latest paper all about?

In general, the response of fluorescent nanoparticles is less informative than that of the dyes – commonly they do not display shifts of spectra or change of anisotropy. But they demonstrate different valuable properties, such as high brightness and photostability. Importantly, they can be assembled into multifunctional nanocomposites, and co-assembly of different types of emitters allows for modulating different properties; for instance, providing composition-dependent wavelength shifting through whole visible range, up to near-IR, or extending their lifetimes to the millisecond range. This is what the review is about. We have to learn how to use these new possibilities.

What do you plan to do next?

In writing this review, I learned a lot myself. This helped me to choose the basic structures for forming functional nanocomposites and the ways to decorate them. My present choice is for carbon nanoparticles that are bright and do not bleach and for silver clusters of several atoms formed on different supports. Both systems are not toxic and can be used in cellular research. They can be co-assembled with organic dyes, combining their valuable properties. Broad horizons are open now for active research and development.