2-(Azido-PEG3-amido)-1,3-bis(NHS Ester) | CAS 2320560-36-7

2-(Azido-PEG3-amido)-1,3-bis(NHS Ester) is a bifunctional click chemistry reagent combining an azide handle with two N-hydroxysuccinimide (NHS) ester groups for rapid conjugation to primary amines. The reagent features a short PEG3-containing linker that improves solubility and spatial separation between the amine-reactive sites and the azide functionality. As a result, it is widely used to prepare azide-bearing biomolecules, surfaces, and nanomaterials for subsequent strain-promoted or copper-catalyzed azide–alkyne cycloaddition workflows in chemical biology and molecular imaging tool development.

1. Antibody And Protein Labeling

2-(Azido-PEG3-amido)-1,3-bis(NHS Ester) is used to introduce an azide functional group onto antibodies and other amine-rich proteins while simultaneously enabling controlled attachment through the NHS esters. Researchers commonly apply this reagent to generate azide-modified IgG, antibody fragments, enzymes, and binding proteins that can later be coupled to alkyne-bearing reporters, affinity handles, or imaging moieties via click chemistry. The PEG3 spacer helps reduce steric constraints around the azide, supporting robust downstream conjugation for probe assembly and multicolor labeling strategies.

2. Surface And Material Functionalization

2-(Azido-PEG3-amido)-1,3-bis(NHS Ester) serves as a practical crosslinking and functionalization intermediate for creating azide-presenting coatings on polymeric and biomaterial surfaces that contain accessible primary amines. In biomaterials and materials chemistry workflows, the NHS esters enable covalent attachment to amine-functionalized substrates such as activated polymers, hydrogel components, and protein-coated surfaces, while the terminal azide provides a standardized handle for subsequent click immobilization. This approach is frequently used to build modular interfaces for biosensor development, cell-interaction studies, and patterned immobilization of ligands or imaging tags.

3. Multivalent Probe Construction

2-(Azido-PEG3-amido)-1,3-bis(NHS Ester) is well suited for constructing multivalent chemical probes where azide availability and conjugation density are key design parameters. By targeting amine groups with the bis-NHS ester functionality, the reagent can install multiple azide sites onto carriers such as dendrimers, polymer backbones, or protein scaffolds, enabling efficient assembly of complex probe architectures through click coupling. This is particularly valuable for generating reagent sets used in target engagement assays, imaging probe panels, and platform studies that require consistent azide presentation for orthogonal attachment of different alkyne-functional components.

4. Nanoparticle And Nanocarrier Conjugates

2-(Azido-PEG3-amido)-1,3-bis(NHS Ester) is used in nanoparticle and nanocarrier chemistry to decorate particles with azide-reactive sites while maintaining colloidal compatibility during functionalization. The NHS esters react with surface-exposed amines on protein corona layers, silica or polymer nanoparticles, and other amine-bearing nanostructures, furnishing an azide-functional surface that can be clicked to alkyne-bearing ligands, fluorophores, or targeting motifs. This reagent is commonly selected when a stable, modular click handle is required to support iterative labeling and assembly of imaging and research reagents on particle-based platforms.