Used in bioconjugation processes to link biomolecules such as proteins, peptides, or antibodies with high specificity due to the strong biotin-streptavidin interaction. The amine group at one end allows for easy coupling to carboxyl or activated ester groups on target molecules. PEG spacer improves solubility, reduces aggregation, and enhances stability in biological environments. Commonly applied in diagnostic assays, targeted drug delivery systems, and surface immobilization in biosensors. The PEG1 linker provides a short, defined distance between biotin and the molecule of interest, minimizing steric hindrance while maintaining binding efficiency.