1,1,1-Trifluoroethyl-PEG2-azide is a crosslinker containing an azide group and a trifluroethyl group. The azide group can participate in Click Chemistry reactions with reagents such as alkynes, DBCO and BCN. The hydrophilic PEG spacer increases solubility in aqueous media. The trifluoroethyl group is used to react with lysine and other primary amine groups in proteins, antibody and other molecules and surfaces.