Water-Soluble BODIPY Dyes for Voltage Imaging

Key words

voltage dyes - fluorophores - BODIPY

Significance

Previously, water solubility of BODIPY dyes was achieved through direct functionalization of the BODIPY fluorophore. Miller and co-workers report an elegant and versatile solution that does not significantly alter the dye electronics through introduction of a sulfonate on the meso-aromatic ring. These fluorophores are used to generate a series of new VoltageFluor (VF) dyes that enable the recording of action potential dynamics in neurons and cardiomyocytes.

Comment

The TFA-catalyzed condensation of aldehydes with pyrroles in the synthesis of BODIPY dyes is commonly performed in CH₂Cl₂ and often reported to be low-yielding. Here, the authors optimized this reaction with their sulfonated aldehyde, which was found to be insoluble in CH₂Cl₂ and toluene. Comparably good yields were obtained in DMF (e.g. 49% over three steps, see above). Therefore, the reported strategy for water-soluble BODIPY synthesis could be very useful for the wider community.