MARTYNENKO Irina St.Petersburg State University of Information Technologies, Mechanics and Optics

Chiral Semiconductor Nanocrystals: Luminescence Properties within Living Cells

Co-authors KUZNETSOVA Vera, ORLOVA Anna, MASLOV Vladimir, FEDOROV Anatoly, GUN’KO Yurii, BARANOV Alexander

Semiconductor nanocrystals, in particular, quantum dots (QDs) have been widely investigated as a new type of therapy and diagnostic agents in many fields of biomedical applications, including live cell imaging. It has therefore become critical to fully understand the interactions between QDs and living cells for long-term, multiplexed, and quantitative photoluminescence detection. Chirality is an important phenomenon in living systems and nearly all biological polymers are homochiral. Recently development of chiroptically active QDs was reported. In this work chiral semiconductor CdSeZnS quantum dots had been prepared with the D- and L- enantiomeric forms of cysteine being used as the stabilizers. D- and L - cysteine stabilized quantum dots produced corresponding mirror image circular dichroism spectra. We have used methods of confocal photoluminescence microscopy and time-resolved photoluminescence microscopy to perform in-vitro study of photoluminescence properties of D- and L - cysteine stabilized quantum dots within living Ehrlich Ascite carcinoma cells. We have demonstrated that the chirality of quantum dots plays significant role on their photoluminescence properties within living cells, while intracellular photoluminescence intensities of enantiomeric L- forms of quantum dots were significantly higher than that of D- forms. More important QD photoluminescence lifetimes were recorded within living cells that open a possibility to understand photophysics of intracellular behavior of different enantiomeric forms of chiral quantum dots.