Azido-PEG1-NHS ester | CAS 1807530-06-8

Azido-PEG1-NHS ester is a heterobifunctional PEG-based reagent that combines an azide handle for copper-free or copper-mediated click chemistry with an NHS ester for reactive coupling to primary amines on biomolecules and surfaces. The short, PEG1 spacer supports water compatibility and reduces steric constraints during subsequent conjugation steps, making it a common building block for modular bioconjugation workflows. Researchers frequently use this reagent to introduce a clickable azide functionality onto proteins, peptides, or polymeric materials, enabling downstream attachment of dyes, affinity tags, or imaging/assay components via click reactions.

1. Protein Amine Labeling

Azido-PEG1-NHS ester is widely used to functionalize proteins and peptides by coupling the NHS ester to accessible primary amines, generating azide-bearing bioconjugates that can be further modified in a controlled manner. This approach is particularly valuable when a direct labeling reagent is not available or when the azide handle is preferred for orthogonal, modular attachment of reporters such as fluorophores, affinity ligands, or solid-support tags. The PEG1 spacer helps maintain aqueous handling and can improve conjugation reproducibility when working with sensitive proteins, enzymes, or multi-domain constructs.

2. Surface Coating And Patterning

Azido-PEG1-NHS ester supports the preparation of azide-functional surfaces and coatings by reacting with amine-containing substrates, including amine-terminated polymers, hydrogel matrices, and biomaterial surfaces. After immobilization, the azide groups serve as robust click handles for subsequent grafting of biomolecules, linkers, or imaging probes, enabling spatially controlled assembly when paired with appropriate click-compatible partners. This use case is common in materials research and platform development where stable, covalently attached functional layers are required for reproducible downstream chemistry.

3. PEG Linker For Biomaterial Functionalization

Azido-PEG1-NHS ester is frequently selected as a PEG-based linker to introduce click-ready azide functionality into biomaterials and polymer conjugates containing primary amines. By installing azide groups on the material backbone or on pendant amines, researchers can later tune attachment of cell-interactive motifs, detection reagents, or scaffold components through click chemistry under conditions compatible with complex macromolecular systems. The compact PEG1 segment is often advantageous when maintaining high local functional density while preserving colloidal stability and minimizing nonspecific aggregation during conjugation and storage.

4. Modular Probe And Tag Construction

Azido-PEG1-NHS ester enables modular construction of research probes by first generating azide-functional intermediates from amine-bearing targets, then using click chemistry to append the desired reporter or recognition element. This workflow is commonly adopted in chemical biology and molecular imaging tool development, where the same azide-bearing scaffold can be diversified by swapping different click partners to create a family of labeled constructs. The reagent’s combination of NHS reactivity and azide click compatibility makes it a practical choice for building standardized conjugation intermediates that integrate readily with automated or high-throughput labeling pipelines.