Single Fluorophore Photobleaching
Photobleaching describes any process that leads to the permanent loss of fluorescence from light-emitting fluorescent species, including organic dye molecules, semiconductor particles such as quantum dots, and fluorescent proteins upon exposure to photons or light. As such processes terminate the flux of photons emanating from a fluorophore, photobleaching serves as a key limiting factor in applications relying on light emission from a fluorophore. Such applications include medical imaging technologies, diagnostics (Diaspro et al. 2006), dye-sensitized solar cells (Grätzel 2003), and light-emitting diodes (Xu et al. 2016).
Photobleaching is caused by photochemical damage of the fluorophore species. Such processes are enhanced by prolonged and intense illumination and are related directly to the probability of photoinduced reactions with solvent and intramolecular reactions of the fluorophore itself that can occur during cycles of photon absorption and...