Biotin acid PEG is a versatile compound that has gained widespread use in the field of drug research and development. It is a derivative of biotin, a B-vitamin that is essential for many biological processes. Biotin-PEG-acid contains three functional groups – biotin, a polyethylene glycol (PEG) linker, and a carboxylic acid group. These functional groups make biotin-PEG-acid a valuable tool in drug research and development as they can be used for a variety of applications, including drug delivery, protein conjugation, and surface modification. In this article, we will explore the functional groups of biotin-PEG-acid and its applications in drug research and development.