Azido-PEG9-amine | CAS 1207714-69-9

Azido-PEG9-amine is a PEG-based linker bearing a terminal azide for copper-free or copper-mediated azide–alkyne click chemistry and a primary amine at the other end for subsequent coupling or surface attachment. The flexible PEG spacer (nine ethylene glycol units) is commonly used to improve solubility, reduce nonspecific interactions, and provide spatial separation between the click handle and the functional payload. This reagent is widely used in chemical biology and biomaterials workflows to install azide functionality on probes, surfaces, and macromolecular constructs prior to conjugation to alkyne-bearing partners.

1. Protein And Peptide Conjugation

Azido-PEG9-amine is used as an azide-functional PEG linker to prepare protein and peptide conjugates for downstream click labeling with alkyne-tagged reagents such as fluorophores, affinity handles, or imaging moieties. The terminal amine enables straightforward incorporation into amine-reactive labeling strategies or coupling to activated carriers, while the azide provides a robust click handle for modular assembly under conditions compatible with sensitive biomolecules. In research settings, the PEG spacer helps maintain accessibility of the reactive azide and can improve conjugate behavior in aqueous buffers, supporting consistent labeling for analytical assays and probe development.

2. Surface Functionalization For Materials

Azido-PEG9-amine is employed to introduce azide groups onto material surfaces and polymeric scaffolds for subsequent click immobilization of alkyne-bearing ligands, coatings, or capture reagents. The amine functionality supports attachment to common surface chemistries and activated substrates, while the PEG chain provides a hydrated, flexible linker that can reduce steric hindrance and nonspecific adsorption. This approach is frequently used in biomaterials science to create clickable interfaces for biosensing platforms, cell-interaction studies, and modular material patterning where spatially controlled presentation of bioactive or analytical components is required.

3. Fluorophore And Imaging Probe Assembly

Azido-PEG9-amine is a practical building block for constructing fluorescent and molecular imaging probes via azide–alkyne click conjugation to alkyne-functional dyes or imaging reporters. The PEG spacer can enhance probe solubility and help preserve photophysical performance by reducing close-contact quenching and improving the effective distance between the dye and the conjugation site. Researchers use this reagent to generate modular probe libraries, enabling rapid exchange of the imaging reporter through click-compatible partners while keeping the azide-bearing precursor consistent across experiments.

4. Bioconjugation Building Block For Assays

Azido-PEG9-amine is used to generate azide-bearing conjugation intermediates for assay reagents, including affinity reagents, detection constructs, and labeling reagents that require modular attachment to alkyne-tagged components. The presence of both an amine and an azide makes it suitable for iterative build strategies, where the amine is used to connect to a carrier or scaffold and the azide is retained for later click installation of a signal or targeting element. This design supports scalable workflows in chemical biology and diagnostic reagent development, where consistent click handles and linker-controlled spacing are important for reproducible reagent performance in assay formats.