Azido-PEG4-acetic Acid | CAS 201467-81-4

Azido-PEG4-acetic Acid is a PEG-based azide building block designed for copper-free and copper-mediated click chemistry workflows. As an azide-functionalized linker, it provides a flexible, water-compatible spacer that can be appended to biomolecules, surfaces, and polymeric materials for downstream conjugation. Its small, reactive azide handle and short PEG4 tether make it a practical reagent for constructing modular bioconjugates, imaging probes, and functional materials in chemical biology and materials research.

1. Bioconjugation Linker Use

Azido-PEG4-acetic Acid is widely used as a reactive azide handle to install PEG spacers onto proteins, peptides, antibodies fragments, and other biomolecular platforms prior to further click-based coupling. Researchers commonly incorporate the PEG4-acetic acid motif to improve solubility, reduce nonspecific interactions, and provide a defined distance between the biomolecule and the next functional group. The reagent is frequently selected when a robust, water-compatible azide functionality is needed for modular assembly of conjugates used in mechanistic studies, assay development, and probe construction.

2. Surface And Material Functionalization

Azido-PEG4-acetic Acid supports the introduction of azide functionality onto polymer surfaces, nanoparticles, and biomaterial coatings to enable subsequent click attachment of dyes, affinity ligands, or capture handles. In materials chemistry and biomaterials science, the PEG4 spacer helps maintain accessibility of the azide group and can mitigate steric crowding at interfaces, which is valuable for reproducible surface labeling. This reagent is commonly employed in workflows that require stable, defined functional density for creating functionalized materials used in sensing, materials characterization, and platform prototyping.

3. Fluorescent Probe And Imaging Tags

Azido-PEG4-acetic Acid is used to prepare azide-bearing scaffolds that can be coupled to fluorescent reporters through click chemistry, enabling the generation of labeling reagents for microscopy and analytical imaging. The PEG4-acetic acid linker provides a hydrophilic, flexible spacing that can improve probe dispersion in aqueous buffers and help preserve labeling accessibility on complex targets. Chemical biology groups often rely on this reagent to generate modular imaging tags that can be rapidly diversified by swapping the complementary click partner.

4. Diagnostic Reagent Building Blocks

Azido-PEG4-acetic Acid is commonly incorporated into reagent design for analytical and diagnostic assay development where azide-functional intermediates are needed for controlled conjugation. The PEG4 tether supports consistent presentation of reactive sites when preparing assay components such as affinity reagents, detection conjugates, and labeled binding partners. By serving as a standardized azide-linker input, it helps streamline downstream assembly of multi-component assay systems used in research laboratories and industrial diagnostic reagent manufacturing workflows.