• fluorescence;
  • fluorescent probes;
  • molecular recognition;
  • peptides;
  • sensors
Thumbnail image of graphical abstract

Fluorescent Probes In their Full Paper on page 14763 ff., T. Nagano et al. describe the selective two-step labeling of proteins with an off/on fluorescent probe. The probe consists of dichlorofluorescein conjugated with nitrilotriacetic acid (NTA)-Ni2+ as the His-tag recognition site and a 2,4-dinitrophenyl ether moiety, which quenches the probe's fluorescence by photoinduced electron-transfer (PeT) from the excited fluorophore to the 2,4-dinitrophenyl ether and also has reactivity with cysteine. Removal of the 2,4 dinitrophenyl ether quencher by a proximity-enhanced reaction with the cysteine residue of the modified tag results in a marked fluorescence increase.