SH-PEG-SH is widely used in bioconjugation and surface modification due to its thiol-reactive end groups. It serves as a crosslinker in the creation of hydrogels, enabling the development of biocompatible materials for drug delivery systems and tissue engineering. In nanotechnology, it is employed to functionalize gold nanoparticles and other surfaces, enhancing stability and biocompatibility. Additionally, it plays a key role in protein and peptide modification, facilitating the attachment of biomolecules for therapeutic and diagnostic applications. Its ability to form disulfide bonds makes it valuable in controlled release systems and targeted drug delivery.