Azidoethyl-SS-propionic NHS ester | CAS 2243566-44-9

Azidoethyl-SS-propionic NHS ester is a bifunctional, NHS-activated ester designed for efficient coupling to primary amines on proteins, peptides, and other amine-bearing biomolecules, while introducing an azide handle for subsequent copper-free or copper-mediated click chemistry. The reagent incorporates a disulfide-containing linker that can support redox-responsive conjugate behavior in many research workflows, enabling intracellularly relevant release or exchange strategies in chemical biology and biomaterials studies. Its azide functionality makes it broadly compatible with strain-promoted azide–alkyne cycloaddition (SPAAC) and related click formats, which is why it is frequently selected for building modular imaging probes, affinity reagents, and functionalized delivery materials.

1. Protein Labeling And Conjugation

Azidoethyl-SS-propionic NHS ester is commonly used to functionalize antibodies, enzymes, and protein scaffolds by reacting the NHS ester with lysine residues to install an azide-bearing, redox-sensitive linker. Researchers use the resulting azide-functional conjugates as versatile intermediates for downstream click attachment of fluorophores, affinity tags, or polymer segments, supporting consistent site-agnostic labeling for assay development and biochemical characterization. The disulfide linkage is particularly valuable when conjugate exchange or reduction-dependent processing is desired during probe construction or material functionalization.

2. Redox-Responsive Imaging Probes

Azidoethyl-SS-propionic NHS ester serves as a practical platform for preparing azide-functional imaging agents where linker redox behavior is leveraged to modulate probe stability and signal persistence in experimental imaging workflows. After NHS-mediated coupling to a targeting protein, peptide, or carrier, the azide handle enables rapid attachment of cyclooctyne/alkyne partners to generate fluorescent or luminescent readouts without requiring extensive intermediate purification. This modular approach is widely adopted in molecular imaging reagent development because it decouples biomolecule conjugation from the final fluorophore or reporter installation step.

3. Surface And Hydrogel Functionalization

Azidoethyl-SS-propionic NHS ester is frequently used to introduce azide groups onto amine-containing surfaces and biomaterial precursors, including functionalized coatings, crosslinked matrices, and hydrogel components derived from proteins or amine-rich polymers. By coupling the NHS ester to available amines, materials scientists generate clickable interfaces that can be patterned or uniformly functionalized with complementary cyclooctyne/alkyne reagents for bioorthogonal immobilization. The disulfide element provides an additional design handle for creating materials with redox-sensitive linker behavior, supporting studies of dynamic cell-material interactions and removable or exchangeable surface chemistries.

4. Affinity Reagents And Capture Platforms

Azidoethyl-SS-propionic NHS ester is used to build azide-bearing affinity reagents such as click-assembled binders and capture constructs derived from proteins, peptides, or other amine-containing recognition elements. After NHS coupling to the recognition component, the installed azide group allows efficient conjugation to solid supports, multivalent scaffolds, or secondary detection moieties via click chemistry, enabling streamlined assembly of assay-ready capture platforms. This workflow is particularly common in research settings that require rapid interchange of targeting modules, reporter chemistries, or support formats while maintaining a consistent conjugation strategy.