Azido-PEG3-amine | CAS 134179-38-7

Azido-PEG3-amine is a PEG-based primary amine functionalized with an azide group, making it a versatile handle for copper-free or copper-mediated azide–alkyne click chemistry workflows. The short, flexible PEG spacer helps maintain accessibility of the azide for labeling and bioconjugation, while the terminal amine enables further derivatization or coupling to activated surfaces and biomolecule scaffolds. As a research-grade click reagent, Azido-PEG3-amine is commonly used to introduce an azide “tag” into complex materials, probes, and linker architectures where controlled attachment chemistry is required.

1. Biomolecule Azide Tagging

Azido-PEG3-amine is widely used to install clickable azide functionality onto proteins, peptides, and other biomolecular constructs through amine-directed derivatization strategies. Researchers incorporate the PEG3 spacer to improve accessibility and reduce steric hindrance during subsequent click labeling, which is particularly valuable when attaching fluorophores, affinity ligands, or imaging moieties to biomolecule scaffolds. The reagent’s bifunctional design supports modular build-up of conjugates used in chemical biology toolkits, including affinity capture reagents and multivalent labeling platforms.

2. Fluorophore And Probe Conjugation

Azido-PEG3-amine serves as a practical intermediate for preparing azide-bearing imaging and detection probes that can be coupled to alkyne-functional dyes, reporter groups, or quencher systems via click chemistry. The PEG3 spacer often improves labeling uniformity by providing a flexible tether between the probe and the conjugation point, which can be important for maintaining optical performance and minimizing non-specific interactions in assay formats. This application is common in molecular imaging reagent development, where azide-functional linkers help standardize probe architectures across different targeting and readout chemistries.

3. Surface and Material Functionalization

Azido-PEG3-amine is frequently employed to functionalize polymer surfaces, nanoparticles, and biomaterial interfaces with azide groups for downstream click attachment of capture molecules, coatings, or signal reporters. The terminal amine enables coupling to activated materials and surface chemistries, while the azide provides a stable, orthogonal reactive handle for subsequent attachment to alkyne partners. In biomaterials science workflows, this approach supports the construction of modular, spatially addressable surfaces and linker-defined materials used for research assays, biosensing interfaces, and scaffold-based probe immobilization.

4. Linker Architecture For Multimodal Tools

Azido-PEG3-amine is used as a building block to create defined linker architectures that combine PEG flexibility with azide click reactivity, enabling the assembly of multimodal research tools. Teams developing complex reagent systems often use Azido-PEG3-amine to standardize the placement of clickable handles relative to an attachment point, facilitating rapid exchange of alkyne-functional components such as targeting units, purification tags, or orthogonal reporters. This strategy is especially useful in chemical biology and molecular imaging pipelines where consistent linker geometry and modular conjugation are required to compare probe variants efficiently.