Used in bioconjugation processes to link biomolecules such as proteins, peptides, or antibodies with high specificity. The biotin moiety allows strong binding to streptavidin or avidin surfaces, commonly used in detection and purification systems. The nPEG spacer improves solubility and reduces steric hindrance, enhancing binding efficiency. The terminal amine group enables covalent attachment to carboxyl or activated ester groups on other molecules. Commonly applied in immunoassays, diagnostic probes, targeted drug delivery systems, and surface immobilization in biosensors. Also used in click chemistry workflows when combined with other functional groups. Stable under physiological conditions, making it suitable for both in vitro and in vivo applications.