Mal-PEG2-NH2 is widely used in bioconjugation and drug delivery systems. Its primary application involves linking biomolecules, such as proteins or peptides, to other compounds or surfaces. The maleimide group reacts selectively with thiol groups, enabling precise attachment to cysteine residues in proteins. This makes it valuable in creating antibody-drug conjugates (ADCs) for targeted cancer therapies. Additionally, the PEG spacer enhances solubility and reduces immunogenicity, improving the stability and bioavailability of conjugated drugs. It is also utilized in surface modification of nanoparticles and in the development of diagnostic probes for imaging applications.