Biotin-PEG4-allyl is widely used in bioconjugation and biochemical research due to its unique properties. The biotin moiety allows for strong and specific binding to avidin or streptavidin, making it valuable in applications such as protein labeling, purification, and detection. The PEG4 spacer enhances solubility and reduces steric hindrance, improving the efficiency of interactions between biotinylated molecules and their targets. The allyl group provides a reactive site for further chemical modifications, enabling the attachment of various functional groups or molecules. This compound is particularly useful in the development of biosensors, drug delivery systems, and diagnostic assays, where precise and stable bioconjugation is essential. Its versatility also extends to surface functionalization in nanotechnology and the study of biomolecular interactions in proteomics and cell biology.