Reaction-based dual signaling of fluoride ions by resorufin sulfonates

We developed new reaction-based probes for the dual signaling of fluoride ions. Selective fluoride-assisted deprotection of resorufin nosylate to generate resorufin fluorochrome was used for signaling. Resorufin nosylate exhibited selective colorimetric and fluorogenic signaling of fluoride ions in acetonitrile. The response from sulfide ions was effectively masked by using the TPEN–Cu²⁺ complex as a source of Cu²⁺ ions for masking sulfide. Selective optical signaling of fluoride was possible in the presence of commonly encountered anions with a detection limit of 1.9 × 10⁻⁶ M.