Azido-PEG3-CH2CO2Me | CAS 1253389-31-9

Azido-PEG3-CH2CO2Me is a PEG-based azide building block designed for copper-free and copper-mediated azide–alkyne cycloaddition (click chemistry) workflows. The reagent combines a short, flexible polyethylene glycol spacer with an azide handle and a methyl ester functional group, enabling convenient incorporation into biomolecule conjugates, polymer materials, and surface coatings where controlled spacing and solubility are required. Its compact structure and ester functionality make it particularly useful for creating clickable intermediates that can be further transformed or used as stable, derivatizable labels in chemical biology and materials research.

1. Clickable Biomolecule Labeling

Azido-PEG3-CH2CO2Me is widely used to introduce an azide functionality into proteins, peptides, and other biomolecular scaffolds that are subsequently functionalized via click chemistry. In research workflows, the PEG3 spacer helps maintain conjugation accessibility and reduces steric congestion around the reactive site, which is valuable when attaching bulky imaging tags, affinity handles, or polymeric reporters. The methyl ester group provides an additional chemical handle for downstream derivatization or conversion to alternative carboxylate forms, supporting modular probe construction for cell-surface chemistry, receptor labeling, and extracellular matrix studies.

2. Surface Coatings And Patterning

Azido-PEG3-CH2CO2Me is commonly employed to functionalize material surfaces with azide groups for patterned immobilization using click-based coupling strategies. Researchers use this reagent to create clickable monolayers or grafted layers on substrates such as glass, polymer films, and sensor surfaces, where PEG spacing can improve wettability and reduce nonspecific interactions. The methyl ester functionality can support further chemical elaboration of the surface layer, enabling fabrication of stable, derivatizable interfaces for materials characterization, microarray-style reagent attachment, and surface-based binding assays that rely on orthogonal post-functionalization.

3. Polymer and Hydrogel Functionalization

Azido-PEG3-CH2CO2Me supports the incorporation of azide moieties into polymer backbones and hydrogel networks to enable post-synthetic functionalization. Polymer scientists and biomaterials groups use the PEG3 linker to tune local mobility and accessibility of the azide groups, which is important for reproducible conjugation density and for uniform attachment of fluorescent dyes, affinity ligands, or bioactive motifs that are introduced through click chemistry. The reagent’s ester group also facilitates chemical modification routes during materials development, helping teams design clickable polymer intermediates for responsive, modular materials platforms.

4. Molecular Imaging Probe Building

Azido-PEG3-CH2CO2Me is used as a practical clickable intermediate in the assembly of molecular imaging probes and labeled research reagents. By providing a PEG-spaced azide handle, it enables efficient attachment of imaging reporters or targeting/recognition components through azide–alkyne cycloaddition, supporting probe modularity across different labeling formats. The methyl ester functionality can be leveraged during probe design to adjust chemical reactivity and to prepare derivatization-ready intermediates, which is especially useful when constructing multicomponent imaging libraries for assay development and chemical biology tool generation.