Hydroxy-PEG12-t-butyl ester is widely used in the field of bioconjugation and drug delivery. Its primary application lies in modifying biomolecules, such as proteins, peptides, and antibodies, to enhance their solubility, stability, and bioavailability. The PEG (polyethylene glycol) chain in the compound helps reduce immunogenicity and prolongs the circulation time of therapeutic agents in the body. Additionally, it is employed in the development of prodrugs, where the t-butyl ester group acts as a protective moiety that can be cleaved under specific conditions to release the active drug. This chemical is also utilized in the synthesis of advanced materials, such as hydrogels and nanoparticles, for targeted drug delivery systems. Its versatility makes it a valuable tool in pharmaceutical research and biotechnology.