A new fluorescent turn-on chemodosimeter for cyanide based on dual reversible and irreversible deprotonation of NH and CH groups

A new fluorescent turn-on cyanide chemodosimeter 5 was developed for the first time based on the irreversible deprotonation/oxidation of the CH group followed by the reversible deprotonation of the NH group, with high selectivity and dramatic red-shifted absorption (approximate to 263 nm). The photoinduced electron transfer (PET) is prevented by the irreversible process, which results in coplanar geometry between indole and naphthalimide causing enhancement of fluorescence.