N-(acid-PEG3)-N-bis(PEG3-azide) | CAS 2182602-17-9

N-(acid-PEG3)-N-bis(PEG3-azide) is a PEG-based, multifunctional azide click chemistry reagent designed for bioconjugation workflows that benefit from hydrophilicity and controlled spacing. As an azide-bearing building block, it is commonly used in copper-free or copper-catalyzed azide–alkyne cycloaddition strategies to install or crosslink biomolecules, surfaces, and polymeric constructs. The reagent’s acid-functional handle and bis(PEG3-azide) architecture make it well suited for constructing multivalent conjugates, tunable linkers, and modular imaging or materials platforms where azide density and accessibility are important.

1. Multivalent Bioconjugation

N-(acid-PEG3)-N-bis(PEG3-azide) is widely used as a PEG spacer and azide-loading reagent to generate multivalent bioconjugates for research-grade labeling of proteins, peptides, and other biomolecular targets. The bis(PEG3-azide) motif supports higher local functional density compared with monofunctional azides, which is valuable when downstream conjugation requires multiple attachment points to maintain binding-site accessibility or to improve coupling efficiency in complex labeling workflows. The acid-functional group provides a convenient anchoring or coupling handle in many bioconjugation schemes, enabling users to prepare azide-terminated constructs that can be further reacted with complementary alkyne partners for modular assembly of probes, affinity reagents, and engineered biomaterials.

2. Surface And Material Functionalization

N-(acid-PEG3)-N-bis(PEG3-azide) is used to functionalize polymeric materials, hydrogels, and device surfaces with azide groups for subsequent click-based patterning and immobilization. In molecular imaging and diagnostic reagent development pipelines, azide-modified substrates are often prepared as intermediate platforms that can be uniformly functionalized and then selectively decorated with alkyne-bearing ligands, reporters, or capture molecules. The PEG3 spacing helps reduce nonspecific interactions and improves accessibility of reactive sites on the material interface, which is particularly relevant when building low-fouling surfaces or when maintaining consistent conjugation behavior across batch-prepared coatings and bulk gels.

3. Molecular Imaging Probe Assembly

N-(acid-PEG3)-N-bis(PEG3-azide) serves as a practical azide component for assembling imaging probes and fluorescent or luminescent conjugates through click chemistry-compatible coupling to alkyne-containing dyes, affinity tags, or scaffold molecules. Its PEG-based design supports solubility and reduces steric hindrance, helping maintain labeling efficiency when probe constructs require multiple functional elements or when conjugates must remain well-dispersed in aqueous labeling buffers. Researchers frequently use bis(PEG3-azide) reagents to tune azide stoichiometry for controlled probe architecture, enabling consistent downstream conjugation to alkyne reporters while preserving modularity for swapping targeting or reporting components.

4. Crosslinking and Polymer Architectures

N-(acid-PEG3)-N-bis(PEG3-azide) is applied in polymer and biomaterials engineering to introduce azide functionality for click-mediated crosslinking, network formation, and multicomponent assembly. The bis(PEG3-azide) structure supports the creation of defined linkages when reacted with complementary alkyne crosslinkers or multifunctional alkyne scaffolds, allowing users to build structured PEG-rich architectures with controlled reactive site spacing. Such azide-functional PEG linkers are commonly used to prepare intermediate materials for subsequent modular modification, including incorporation of imaging handles, affinity motifs, or surface-active groups, thereby supporting iterative development of advanced research materials and reagent platforms.