A gold(III) ion-selective fluorescent probe and its application to bioimagings.

A highly selective and sensitive fluorescent chemosensor for Au3+ has been reported. The system utilizes an irreversible Au3+-promoted cyclization reaction of a rhodamine amide tethered with an alkyne. The probe can sense Au3+ ions selectively over other biologically relevant metal ions, and similar to 50 nM of Au3+ could be readily detected in aqueous media. Fluorescent imaging of Au3+ in living cells is also successfully demonstrated.