Azido-PEG23-amine | CAS 749244-38-0

Azido-PEG23-amine is a PEG-based primary amine functionalized with a terminal azide, designed as a versatile handle for copper-free and copper-mediated click chemistry workflows. As a long, flexible, hydrophilic linker, it supports bioconjugation and surface functionalization by minimizing steric constraints while maintaining efficient azide reactivity. The combination of an azide group and a terminal amine makes this reagent useful for attaching PEGylated motifs to biomolecules, nanoparticles, and polymeric materials, where downstream conjugation and controlled spacing are critical.

1. PEGylated Bioconjugation

Azido-PEG23-amine is widely used in bioconjugation programs to introduce a PEG spacer that improves solubility and reduces nonspecific interactions while preserving a reactive azide for subsequent click coupling. Researchers commonly incorporate the terminal amine for amide bond formation, reductive amination, or other coupling strategies to biomolecule scaffolds, leaving the azide available as a modular attachment point. This workflow is frequently applied in labeling strategies for proteins, peptides, and affinity ligands, enabling site-specific or modular assembly of fluorescent tags, affinity probes, or capture handles through azide–alkyne click chemistry.

2. Surface Functionalization Tools

Azido-PEG23-amine serves as a practical reagent for preparing azide-functional surfaces and interfaces where long-range accessibility is needed. The terminal amine enables attachment to activated surfaces, coatings, or polymer matrices, while the PEG chain provides a hydrated, flexible environment that supports efficient subsequent click reactions with alkyne-bearing partners. This is commonly leveraged to build biointerfaces for assay development, immobilized reagent platforms, and research-grade materials where controlled surface spacing can influence binding behavior and labeling density.

3. Molecular Imaging Labeling

Azido-PEG23-amine is used as a linker component in molecular imaging reagent development to create azide-bearing conjugates that can be rapidly assembled with imaging reporters via click chemistry. The PEG23 spacer helps manage steric effects and improves compatibility with aqueous labeling conditions, which is particularly valuable when attaching bulky fluorophores, reporter scaffolds, or multivalent imaging constructs. In imaging workflows, the amine functionality supports incorporation into targeting or recognition components, while the azide provides a standardized coupling site for modular installation of imaging moieties.

4. Diagnostic Probe Construction

Azido-PEG23-amine is a common building block in the construction of diagnostic and analytical probes that rely on click-compatible conjugation chemistry. The reagent’s amine group allows incorporation into probe architectures such as antibody fragments, enzyme-binding scaffolds, nucleic-acid-associated materials, or affinity reagents, with the azide preserved for orthogonal assembly steps. Downstream, azide–alkyne click coupling is used to attach detection elements or reporter conjugates, supporting consistent probe formatting and enabling rapid iteration of probe design during assay optimization and method development.