A cascade reaction-based switch-on fluorescent sensor for Ce(iv) ions in real samples.

We herein report a cascade reaction-based switch-on fluorescence sensor for Ce(iv) ions. The mechanism is based on the ability of Ce(iv) ions to oxidize β-naphthol, which condenses with o -phenylenediamine to generate fluorescent benzo[ a ]phenazine. The sensor achieved a 200-fold fluorescence enhancement and was successfully applied to real sample detection.