A β-D-glucose ligand equipped with a free thiol through a hydrophilic PEG3 spacer. The thiol reacts with maleimides to form stable thioether conjugates or with other thiols to form disulfide bonds; it is also compatible with thiol-gold chemistry for surface immobilization. This compound provides a β-D-glucose building block for glycoconjugate synthesis, glycomimetic research, and the construction of probes for glucose-recognizing proteins and lectins.