Used in surface modification of gold nanoparticles and biosensors due to its thiol group, which strongly binds to gold surfaces. The ethylene glycol chain provides excellent resistance to non-specific protein adsorption, making it ideal for creating biocompatible interfaces in diagnostic devices and drug delivery systems. Frequently employed in self-assembled monolayers (SAMs) to reduce biofouling and improve stability in biological environments. Also applied in immobilizing biomolecules like proteins and DNA on sensor surfaces while maintaining their activity.