SH-PEG-NH2 is widely used in bioconjugation and surface modification due to its dual functional groups. The thiol (-SH) group allows for binding to gold surfaces or other thiol-reactive materials, making it valuable in creating biosensors and functionalized nanoparticles. The amine (-NH2) group facilitates covalent attachment to carboxylated molecules or surfaces, enabling the immobilization of proteins, peptides, or other biomolecules. This chemical is particularly useful in drug delivery systems, where it helps in the controlled release of therapeutic agents. Additionally, it is employed in tissue engineering to modify scaffolds for improved cell adhesion and growth. Its versatility also extends to diagnostic applications, where it enhances the stability and specificity of assay components.