Azido-PEG7-azide | CAS 225523-86-4

Azido-PEG7-azide is a polyethylene glycol (PEG)-based bifunctional azide building block designed for click chemistry workflows that require orthogonal or multivalent azide presentation. As a bis-azide reagent, it provides two reactive azide termini separated by a flexible PEG7 spacer, enabling efficient incorporation of azide handles into biomolecules, polymers, and surfaces for downstream strain-promoted or copper-catalyzed azide–alkyne cycloaddition. Its PEG architecture is commonly selected to improve solubility, reduce nonspecific interactions, and support multivalent labeling strategies used in chemical biology, materials functionalization, and molecular imaging reagent development.

1. Multivalent Biomolecule Labeling

Azido-PEG7-azide is widely used to introduce two azide groups onto proteins, peptides, and other biomolecular scaffolds, supporting multivalent conjugation schemes that benefit from increased local density of reactive sites. Researchers often incorporate the PEG spacer to maintain aqueous compatibility and to help preserve binding or recognition features of sensitive targets during labeling workflows. This reagent is particularly relevant when downstream coupling requires multiple click handles for modular assembly of imaging probes, affinity reagents, or library-scale labeling constructs.

2. Polymer and Hydrogel Functionalization

Azido-PEG7-azide is commonly employed to functionalize synthetic polymers and hydrogel networks with azide moieties for later click-based attachment of dyes, affinity ligands, or bioactive motifs. The PEG7 linker provides a flexible, hydrophilic spacing between azide termini, which can improve accessibility of reactive groups within crowded polymer environments. Material scientists use this approach to generate click-reactive surfaces and 3D matrices that enable spatially or temporally controlled grafting of additional components via azide–alkyne cycloaddition.

3. Surface and Nanomaterial Conjugation

Azido-PEG7-azide is used in surface chemistry and nanomaterial engineering to install azide handles on substrates such as beads, nanoparticles, and patterned surfaces for subsequent click coupling. The bifunctional azide design supports strategies where azide density and presentation are tuned to match the geometry of the target surface or particle, improving the practicality of multistep assembly workflows. In molecular imaging and diagnostic reagent development, azide-functionalized platforms derived from this reagent can serve as modular scaffolds for attaching reporter groups and targeting elements through click-compatible chemistries.

4. Modular Probe and Reagent Assembly

Azido-PEG7-azide supports modular construction of click-reactive probe intermediates by providing two azide termini for iterative conjugation and scaffold building. Chemical biology and assay development teams often rely on bis-azide reagents to create standardized intermediate materials that can be rapidly diversified with complementary alkyne-bearing partners, including fluorophores, affinity tags, and polymerizable reporters. The PEG7 spacer helps maintain solubility and reduces aggregation tendencies in labeling and reagent formulation contexts, making it a practical choice for building consistent, scalable click-ready components.