Used in bioconjugation to link biomolecules such as proteins, peptides, or antibodies in a controlled manner due to its reactive thiol ends. Enables the formation of stable PEGylated products that improve solubility, reduce immunogenicity, and extend circulation time of therapeutic agents. Commonly applied in drug delivery systems, particularly for creating PEG-protein conjugates. Facilitates surface modification of gold nanoparticles and other thiol-reactive surfaces for biosensors and diagnostic devices. Used in hydrogel formation for tissue engineering by crosslinking with maleimide-functionalized polymers. Supports site-specific labeling in research and development of biopharmaceuticals.