Recent advances in ratiometric luminescence sensors

Ratiometric luminescent sensors have been of considerable interest to the chemo/biosensor with the ability of providing a precisely quantitative and qualitative analysis. The main strategies for generating dual emissions from single-fluorophore and double-fluorophore are summarized and categorized in detail. Typically, dual emission can be obtained either with fluorescence resonance energy transfer or intramolecular charge transfer. The discovery of aggregation induced emission offers new opportunities for ratiometric sensing. Ratiometric phosphorescence and chemiluminescence analysis are also promising for sensing. The recent progress for applications of ratiometric luminescent method is addressed and summarized here, which shows that ratiometric luminescent method can be used not only to selectively quantify one substance, but also to qualitatively recognize different substances.