Responsive and reactive terbium complexes with an azaxanthone sensitiser and one naphthyl group: applications in ratiometric oxygen sensing in vitro and in regioselective cell killing.

A terbium complex has been designed that may be used to sensitise formation of singlet oxygen (phi(em) 12%), allowing the creation of a ratiometric sensory system for pO(2) (versus the insensitive Eu analogue) and the definition of a reactive probe that can be used to cause local damage to cells loaded with the complex and exposed to laser excitation.