Fluorescence detected circular dichroism: a particularly sensitive technique to appreciate low levels of chirality

Chirality is the absence of mirror symmetry. This property governs the behavior in the most biologically important molecules, amino acids, sugars, the DNA itself. Chiral recognition of molecules is therefore a factor of great importance in the pharmaceutical and agrochemical industries, as well as in medicine. Chiral molecules can be characterized by optical experiments based on the chiro-optic excitation of molecules. In particular, chiral materials typically absorb left and right circular polarized light differently, that is, they possess circular dichroism (CD). Unfortunately, the natural CD of most molecules is very low and is in the ultraviolet range. Hence, new techniques serve practical purposes to increase the sensitivity in the identification of these properties. With a collaboration within the SBAI department of ICI between the spectroscopy and organic synthesis laboratories, the technique of CD detection by fluorescence measurements was used. This technique is a fast and sensitive tool for the study of chiral molecules that emit light that allows to detect very small differences in absorption by measuring the difference in emission when the molecules are stressed by circularly polarized light. In this work, we perform fluorescence CD measurements on novel chiral amide compounds, designed specifically for visible light emission. We believe that these compounds can be coupled with plasmonic nanostructures, in order to further improve efficiency in applications involving chiral detection or chiral emission of molecules.



Aggiornato al 04/14/2022 - 14:25

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