Propargyl-PEG4-S-PEG4-t-butyl ester is a PEG linker containing a propargyl group and t-butyl group. The propargyl groups can react with azide-bearing compounds or biomolecules via copper catalyzed azide-alkyne Click Chemistry to yield stable triazole linkages. t-butyl ester is a better leaving group compared to a hydroxyl group. The hydrophilic PEG spacer increases solubility in aqueous media.
