Used as a hydrophilic linker in the synthesis of antibody-drug conjugates (ADCs) and other bioconjugates. Its polyethylene glycol (PEG)-like structure enhances solubility and improves the pharmacokinetic properties of conjugated molecules. The terminal hydroxyl group can be functionalized for coupling, while the nitrophenoxy moiety may serve as a leaving group or a site for further modification. Commonly applied in drug delivery systems to spacer components between targeting agents and active payloads, helping to reduce aggregation and increase stability in biological environments. Also utilized in surface functionalization of nanoparticles and biosensors due to its ability to form stable, biocompatible coatings.