Aminooxy-PEG1-azide | CAS 2100306-70-3

Aminooxy-PEG1-azide is a bifunctional, PEG-linked azide click chemistry reagent combining an aminooxy handle with a terminal azide for orthogonal conjugation workflows. As an azide-based click partner, it is commonly used in strain-promoted azide–alkyne cycloaddition (SPAAC) and related bioorthogonal labeling strategies, while the aminooxy functionality supports oxime-based coupling to carbonyl-bearing biomolecules or surfaces. Its compact PEG1 spacer helps balance reactivity and solubility, making it a practical building block for preparing labeled probes, functional biomaterials, and imaging reagents where controlled attachment and minimal steric interference are important.

1. Protein Oxime Conjugation

Aminooxy-PEG1-azide is used to introduce a clickable azide functionality onto proteins and protein-derived reagents through aminooxy–carbonyl oxime formation, enabling subsequent bioorthogonal attachment steps. Researchers employ it to generate azide-tagged antibodies, antibody fragments, enzymes, or protein scaffolds that can be further functionalized with cyclooctyne/alkyne partners for imaging, affinity enrichment, or multicomponent labeling. The short PEG1 linker is particularly useful when maintaining accessibility of the azide for downstream click labeling while preserving solubility and reducing nonspecific interactions during conjugate preparation and handling.

2. Cell Surface Labeling Probes

Aminooxy-PEG1-azide supports the construction of azide-bearing labeling probes intended for cell-associated targets, where sequential conjugation enables modular probe assembly. In typical workflows, carbonyl-functional ligands or targeting components are first coupled via the aminooxy group to install the azide handle, and the resulting azide conjugate is then used in SPAAC with fluorescent cyclooctyne reagents or other functional cyclooctyne partners. This approach is favored in chemical biology because it separates targeting installation from fluorophore or reporter attachment, improving flexibility for building probe libraries and optimizing labeling conditions for membrane-associated or extracellular biomolecule studies.

3. Imaging and Fluorophore Assembly

Aminooxy-PEG1-azide is widely used as a reagent for assembling imaging-ready conjugates by providing a defined azide handle compatible with rapid click labeling. After installing the azide onto an imaging scaffold through aminooxy coupling to appropriate carbonyl groups, the conjugate can be reacted with cyclooctyne-based dyes, quencher pairs, or reporter modules to generate fluorescent or luminescent probes with controlled stoichiometry. The PEG1 spacer helps maintain effective dye accessibility and reduces aggregation tendencies during labeling, which is valuable for preparing consistent probe batches for microscopy workflows and molecular imaging reagent development.

4. Functional Biomaterials Modification

Aminooxy-PEG1-azide is used to functionalize biomaterial surfaces and polymeric materials with azide groups that can be subsequently patterned or coupled via click chemistry. Materials scientists commonly incorporate the aminooxy functionality to attach the reagent to carbonyl-containing coatings, surfaces, or material-bound biomolecules, producing azide-functional interfaces for later immobilization of bioactive ligands, crosslinking motifs, or reporter elements using SPAAC. This modular strategy supports the fabrication of clickable hydrogels, coatings, and assay-ready surfaces where spatially controlled conjugation and repeatable surface chemistry are required for downstream research and diagnostic reagent development.