mPEG4-azide | CAS 606130-90-9

mPEG4-azide is a short, methoxy-terminated polyethylene glycol azide designed for bioorthogonal click chemistry workflows. As an azide-bearing PEG reagent, it is commonly used as a reactive handle in strain-promoted or copper-catalyzed azide–alkyne cycloaddition strategies, enabling modular attachment of PEG to biomolecules, surfaces, and soft materials. Its compact PEG architecture supports improved solubility, reduced nonspecific interactions, and convenient incorporation of PEG functionality into imaging probes, conjugates, and material platforms.

1. PEGylation Of Biomolecules

mPEG4-azide is widely used to introduce a defined PEG segment onto proteins, peptides, and nucleic-acid constructs as part of conjugate design for research-grade bioconjugation. The azide functionality provides a convenient attachment point for downstream click coupling to complementary cyclooctyne or alkyne partners, allowing researchers to tune hydrophilicity and colloidal behavior without extensive post-processing. This is particularly useful when maintaining aqueous compatibility and minimizing aggregation are critical for assay readiness, labeling workflows, or multicomponent conjugate assembly.

2. Surface And Material Functionalization

mPEG4-azide is applied in biomaterials and interface engineering to install PEG-like antifouling and steric stabilization layers on polymer surfaces, nanoparticles, and hydrogel systems. By using the azide handle as a click-compatible group, teams can pattern or decorate materials with PEG moieties in a modular fashion, supporting reproducible surface chemistry for subsequent ligand attachment, probe immobilization, or characterization studies. The short PEG length is often selected to balance stealth properties with accessibility of nearby functional groups on the material scaffold.

3. Imaging Probe And Sensor Building

mPEG4-azide serves as a practical PEG linker component for constructing fluorescent, luminescent, or affinity-based detection reagents where controlled spacing and improved solubility are required. Researchers incorporate the azide-bearing PEG to help manage probe dispersion in aqueous buffers and reduce nonspecific adsorption during labeling and measurement workflows. Click-compatible coupling to imaging tags or recognition elements enables rapid generation of probe libraries for optimization of labeling density, conjugate stability, and compatibility with analytical instrumentation.

4. Diagnostic Reagent Conjugate Platforms

mPEG4-azide is commonly used in the development of research diagnostic reagent components, including multivalent binding constructs and assay-ready conjugates that require consistent solvation and reduced background interactions. The azide group supports orthogonal assembly with complementary click partners, enabling straightforward integration of PEG segments into complex reagent architectures such as labeled affinity reagents, bead-based assay components, or multiplexing-ready conjugates. Its PEGylated character helps maintain workflow robustness across washing, incubation, and storage conditions typical of laboratory assay development.