A triantennary N-acetylgalactosamine (Tri-GalNAcβ) ligand presenting three β-GalNAc residues on a tris-based branched scaffold, equipped with a sulfo-N-hydroxysuccinimide (sulfo-NHS) activated ester through a hydrophilic pentaethylene glycol (PEG5) spacer. The sulfo-NHS ester reacts with primary amines to form stable amide bonds, providing a straightforward route to conjugate the Tri-GalNAc targeting ligand onto amine-bearing molecules and surfaces. The sulfonate group on the NHS ring confers improved aqueous solubility relative to standard NHS esters, enabling conjugation reactions in fully aqueous buffers without organic co-solvents. This compound enables the construction of hepatocyte-targeted therapeutics and research tools that exploit the asialoglycoprotein receptor (ASGPR), which is highly expressed on liver hepatocytes and binds GalNAc-containing ligands with high affinity. The trivalent presentation of GalNAcβ residues engages multiple carbohydrate-recognition domains of ASGPR simultaneously, producing high-avidity binding that substantially exceeds the affinity of monovalent GalNAc ligands and closely mimics the geometry of clinically validated Tri-GalNAc targeting moieties used in approved GalNAc-siRNA therapeutics.