Highly water-soluble, OFF-ON, dual fluorescent probes for sodium and potassium ions

Fluorescent probes 1 and 2 were conveniently synthesized from 4-sulfo-1, 8-naphthalic anhydride, potassium salt, and 4'-aminobenzo-15-crown-5 and also from 4'-aminobenzo-18-crown-6. These sensors exhibit dual emission and ratiometric absorption, are water soluble, and show good selectivity for sodium and potassium ions. Published by Elsevier Ltd.