m-PEG2-azide | CAS 215181-61-6

m-PEG2-azide is a short-chain methoxy-terminated polyethylene glycol (PEG) linker bearing a terminal azide handle, designed for copper-free or copper-mediated azide–alkyne click chemistry workflows. As a PEGylated azide, it combines the biointerface-reducing and solubilizing properties of PEG with the modularity of an azide functional group for downstream conjugation. This reagent is commonly used to install PEG spacers onto biomolecules, surfaces, and polymeric materials, enabling controlled physicochemical tuning and facile attachment of imaging, affinity, or labeling components.

1. PEG Spacer Bioconjugation

m-PEG2-azide is widely used as a compact PEG spacer in bioconjugation strategies where an azide-functional handle is required for subsequent click coupling to alkyne-bearing partners. Researchers incorporate it to modulate local hydrophilicity and steric environment around proteins, peptides, or other macromolecules, improving conjugate solubility and reducing nonspecific interactions in labeling and assay development. The reagent’s short PEG length supports applications that need modest spacing rather than long PEG chains, making it attractive for preparing well-defined conjugation scaffolds for research-grade probes and reagent sets.

2. Surface Functionalization Click

m-PEG2-azide supports the fabrication of PEGylated, azide-terminated surfaces for materials and interface engineering, including microarrays, sensor surfaces, and patterned biomaterials. By introducing an azide functionality onto otherwise reactive or functionalized substrates, teams can perform subsequent click attachment of fluorescent tags, affinity ligands, or polymer brushes under conditions compatible with surface workflows. This approach is frequently used to create low-fouling interfaces and to spatially control the display of functional moieties for analytical chemistry, chemical biology, and diagnostic reagent development.

3. Fluorophore and Probe Labeling

m-PEG2-azide is used to generate azide-bearing labeling intermediates that can be clicked to alkyne-functional fluorophores, affinity reporters, or detection reagents. In molecular imaging and assay chemistry, the PEG spacer helps tune probe solubility and reduces aggregation tendencies, which is particularly valuable when working with hydrophobic dyes or multicomponent labeling schemes. Probe developers also use m-PEG2-azide to standardize linker length across probe libraries, supporting consistent performance in comparative experiments and enabling modular swapping of reporter groups via click-ready azide chemistry.

4. Polymer and Hydrogel Modification

m-PEG2-azide is commonly applied in polymer chemistry and biomaterials workflows to introduce azide groups into PEG-containing networks, hydrogels, or functional polymer backbones for later click crosslinking or post-modification. Materials scientists use the reagent to adjust swelling behavior, surface hydration, and mechanical or interfacial properties by incorporating PEG segments while retaining a reactive azide handle for orthogonal attachment of functional components. This enables the construction of modular material platforms where functional groups can be installed after initial polymer formation, supporting reproducible preparation of research tools used in chemical biology and materials characterization.