SH-PEG-OH is widely used in bioconjugation and surface modification due to its reactive thiol (-SH) and hydroxyl (-OH) groups. It serves as a linker in drug delivery systems, enabling the attachment of therapeutic agents to targeting molecules or nanoparticles. In material science, it is employed to modify surfaces, enhancing biocompatibility and reducing non-specific binding. The thiol group allows for covalent bonding with gold or other metal surfaces, making it valuable in biosensor development. Additionally, it is utilized in hydrogel formation for tissue engineering, providing a scaffold for cell growth and regeneration. Its water-soluble PEG backbone ensures stability and reduced immunogenicity in biomedical applications.