t-boc-N-amido-PEG7-azide is a PEG molecule with an azide(N3) group and Boc-protected amino group. The hydrophilic PEG spacer increases solubility in aqueous media. The azide group is reactive with alkyne, BCN, DBCO via Click Chemistry to yield a stable triazole linkage. The Boc group can be deprotected under mild acidic conditions to form the free amine.