Tetrafluorophenyl (TFP) esters chemistry typically used to attach fluorophores or haptens to the primary amines of biomolecules. They produce as strong amide bound than succinimidyl esters (SE, Hydroxysuccinimide- or NHS-ester), but TFP esters are less susceptible to spontaneous hydrolysis during conjugation reactions. TFP esters are stable for several hours at the basic pH, far outlasting succinimidyl esters.
References
Tetrafluorophenyl esters Wikipedia(Text) CC BY-SA