In chemical biology, the fluorescent labeling of molecules and usage of fluorescence-based imaging techniques for visualizing molecular interactions at a subcellular level is a key feature and contributes significantly to the elucidation of disease mechanisms. Furthermore, potential drug target sites can be identified, drugs acting on such sites can be developed, and by their labeling, the interactions of drugs and targets can be uncovered. In this work, innovative approaches for the fluorescent labeling of proteins, nucleic acids, and drugs are presented. A novel methodology for the facile synthesis of a versatile, functionalized, water-soluble, and tunable fluorescent probe has been developed. As a class of promising drug