Used as a bifunctional linker in bioconjugation, enabling the attachment of molecules to surfaces or biomolecules via its amine and carboxylic acid groups. Its long PEG chain provides high solubility in water and reduces non-specific binding, making it ideal for assays and labeling in biological systems. Commonly applied in the development of PEGylated peptides, protein modifications, and drug delivery systems to improve stability and pharmacokinetics. Also used in creating functionalized surfaces for biosensors and microarrays due to its spacer properties that enhance accessibility and reduce steric hindrance.