DOFL compounds are generated by combinatorial modification of organic fluorescent scaffolds, where simple building blocks can be assembled with the aim of creating diverse compounds. The design and preparation of DOFL focus on exploring the diverse chemical space directly around a fluorescent scaffold. This approach provides some advantages in the development of bioimaging probes since it can be applied without knowledge about the target molecule and an additional reporter is not required for the visualization of the probes. Therefore, DOFLA depends entirely on the structural diversity of the fluorescence library empowered by the unbiased evaluation of compounds to identify target-selective fluorescent probes. DOFL derived from fluorescence scaffolds such as rosamine, BODIPY, chalcone, and xanthone covers a very wide range of chemical space and fluorescence spectra (400−800 nm).
Imaging probes which conduct live-cell distinction can be classified into two groups: Holding-Oriented Live-cell Distinction (HOLD) probes and Gating-Oriented Live-cell Distinction (GOLD) probes. HOLD probes hold macromolecules which can act as biomarkers, visualizing specific cells. GOLD probes are substrates of transporters, whose cell-type-specific accumulation is majorly dependent on transporters.