Fluorescent Analogs of Biomolecular Building Blocks: Design, Properties, and Applications

The designing fluorescent probes for the four major families of macromolecular building blocks, lipids, monosaccharides, amino acids, and nucleosides, are studied. In an ideal situation, an emissive analog of any naturally occurring biomolecular building block should closely resemble its natural counterpart and retain the original function. The study revealed that not all applications require the strict imposition of isomorphic design criteria. Furthermore, the different chemical natures of the distinct families of biomolecular building blocks inherently control the possible structural and electronic changes. The heterocyclic nucleobases provide a fertile platform for modifications that easily alter the photophysical characteristics. This also holds true for certain aromatic amino acids. In contrast, turning phospholipids or monosaccharides into emissive analogs requires rather creative and sometimes drastic modifications, with saccharides being viewed as the most limiting in this respect.