CHO-PEG-COOH is widely used in bioconjugation and drug delivery systems due to its reactive aldehyde (CHO) and carboxylic acid (COOH) groups. The aldehyde group allows for selective conjugation with amine-containing molecules, such as proteins or peptides, forming stable Schiff base linkages. This property is particularly useful in creating targeted drug delivery systems, where the molecule can be attached to antibodies or other targeting agents for precise delivery to specific cells or tissues.

The carboxylic acid group provides additional functionality for further modification or coupling with other molecules, enabling the creation of complex nanostructures or hydrogels. This makes it valuable in tissue engineering, where it can be used to design scaffolds that promote cell adhesion and growth. Additionally, its water-soluble PEG backbone enhances biocompatibility and reduces immunogenicity, making it suitable for biomedical applications such as the development of therapeutic nanoparticles or biosensors. Its versatility also extends to surface modification, where it can be used to functionalize materials for improved interaction with biological systems.