mPEG3-azide | CAS 74654-06-1

mPEG3-azide is a short-chain methoxy-poly(ethylene glycol) azide designed for copper-free and bioorthogonal click chemistry workflows. As an azide-functional PEG building block, it provides a hydrophilic, sterically flexible handle that is commonly used to install or exchange functional groups on biomolecules, nanoparticles, and polymer systems via azide–alkyne cycloaddition. Its compact mPEG architecture supports fast conjugation and improved solubility, making it a frequent reagent choice in probe labeling, surface functionalization, and materials modification where PEGylation and click-ready chemistry are required.

1. Bioorthogonal PEGylation

mPEG3-azide is widely used as a PEGylation reagent for preparing click-compatible PEG coatings on proteins, peptides, and other biomolecular constructs. Researchers incorporate the azide-terminated PEG to tune solubility, reduce nonspecific adsorption, and improve colloidal stability while maintaining a reactive handle for downstream conjugation to alkyne-bearing partners. In molecular imaging and chemical biology workflows, the reagent is often selected to introduce a defined PEG spacer that can modulate accessibility of binding or recognition elements after conjugation.

2. Surface and Nanoparticle Functionalization

mPEG3-azide supports azide-based surface modification of nanoparticles, liposomes, and polymeric particles where PEG layers are used to control dispersibility and minimize aggregation. Materials teams use the reagent to create click-ready interfaces that can be subsequently coupled with alkyne-functional ligands, targeting motifs, or imaging tags under mild conditions compatible with sensitive assemblies. This approach is commonly adopted in diagnostic reagent development and platform prototyping, enabling modular exchange of surface chemistries without redesigning the entire particle formulation.

3. Fluorescent and Imaging Probe Conjugates

mPEG3-azide is frequently employed to build imaging and detection reagents that require both PEG-mediated solubilization and a defined conjugation site for attaching fluorophores or other reporters. By introducing an azide-functional PEG spacer, probe developers can couple to alkyne-containing dyes, affinity tags, or scaffold molecules to generate well-behaved labeling reagents for assay development and analytical characterization. The small PEG length is particularly useful when a balance between minimal steric impact and improved aqueous compatibility is desired.

4. Polymer Building Blocks and Materials

mPEG3-azide is used as a click-reactive PEG building block for constructing functional polymer hybrids and PEG-functional material surfaces. Polymer chemists and biomaterials scientists incorporate the azide handle to enable modular post-functionalization, such as grafting PEG segments or linking polymer components to alkyne-bearing crosslinkers, linkers, or capture groups. This enables rapid generation of material libraries for studying surface chemistry effects, linker spacing, and interfacial accessibility in biosensing and materials research settings.