LAUSR

Rhodamine B derivatives (RBP)-modified UCNPs (UCNPs@mSiO2–RBP) were developed as a fluorescent turn-off–on sensor based on FRET and IFE to detect Cu2+ and pyrophosphate (PPi) with a wide linear response range (0–10 μM for Cu2+ and 5–35 μM for PPi, much wider than that reported previously) and high sensibility (117 nM for Cu2+ and 70 nM for PPi). The MTT experiments and the bioimaging experiments show its promising prospect in tissue imaging.