2-(Azido-PEG2-amido)-1,3-propandiol | CAS 1398044-52-4

2-(Azido-PEG2-amido)-1,3-propandiol is a PEG-based azide functional handle designed for copper-free or copper-mediated azide–alkyne click chemistry workflows. The reagent combines an azide for orthogonal conjugation with a short, hydrophilic PEG2 spacer and a propanediol-containing amide motif, enabling improved solubility and controlled presentation of the reactive group on biomolecule and material surfaces. As a versatile click-ready intermediate, it is commonly selected for building block strategies in chemical biology, probe development, and surface functionalization where a defined PEG spacer is advantageous for reducing nonspecific interactions and tuning conjugate properties.

1. Biomolecule PEGylation

2-(Azido-PEG2-amido)-1,3-propandiol is used as an azide-bearing PEG spacer building block to introduce hydrophilicity and steric control onto proteins, peptides, and nucleic-acid conjugates prior to downstream click coupling. Researchers often incorporate this reagent when they want the conjugation handle to be presented at a short distance from the biomolecule, supporting consistent labeling density and improved handling in aqueous buffers. The propanediol/amide framework provides a stable linkage point for preparing azide-functional intermediates that can be reacted with complementary alkyne partners to generate well-defined PEG-extended bioconjugates for imaging probes and biochemical assays.

2. Affinity Probe Conjugation

2-(Azido-PEG2-amido)-1,3-propandiol serves as a practical click handle for assembling affinity-based detection reagents, including antibody fragments, receptor-binding ligands, and other targeting moieties that require modular attachment to reporter tags. By using the azide functionality as the reactive anchor and the PEG2 spacer to moderate local charge and accessibility, the reagent supports efficient transfer of labeling groups such as fluorophores, enzyme substrates, or enrichment tags through subsequent click reactions. This approach is widely used in molecular imaging reagent development and diagnostic-reagent research settings where reproducible conjugate architecture and aqueous compatibility are critical for reliable assay workflows.

3. Surface And Material Functionalization

2-(Azido-PEG2-amido)-1,3-propandiol is applied to functionalize polymeric and biomaterial surfaces with azide groups that can later be coupled to alkyne-bearing linkers, coatings, or bioactive motifs. The PEG2 spacer improves compatibility with hydrated environments and helps maintain accessibility of the reactive site after immobilization, which is important for creating stable, addressable interfaces for biosensing and materials chemistry. Teams working on microarrays, hydrogel modification, and functional coating development use azide–PEG linkers like this reagent to enable modular post-assembly patterning and to tune surface interactions without requiring extensive redesign of the underlying material platform.

4. Imaging Probe Building Blocks

2-(Azido-PEG2-amido)-1,3-propandiol is frequently selected as a click-compatible PEG spacer for constructing imaging and tracking probes that require controlled linker length between a targeting element and a reporter. The azide group provides a convenient conjugation site for rapid coupling to alkyne-functional dyes, nanoparticles, or imaging scaffolds, while the PEG2 segment helps reduce aggregation and nonspecific adsorption in probe formulations. In chemical biology and molecular imaging research, this reagent supports the generation of probe libraries where systematic variation of linker presentation can be achieved by swapping complementary alkyne partners while keeping the azide handle constant.