Propargyl-PEG3-O-C1-NHS ester | CAS 2144777-76-2

Propargyl-PEG3-O-C1-NHS ester is a PEG-based NHS ester click chemistry reagent that couples a propargyl (alkyne) handle to an NHS-activated ester for efficient amide formation with primary amines. As a bifunctional linker, it is commonly used to prepare alkyne-functional biomolecules, surfaces, and materials that can subsequently participate in copper-catalyzed azide–alkyne cycloaddition (CuAAC) or related click conjugation workflows. The short PEG3 spacer and activated ester design support robust conjugation in labeling, bioconjugation, and molecular imaging tool development where controlled distance and improved solubility are beneficial.

1. Amine Labeling For Click

Propargyl-PEG3-O-C1-NHS ester is widely used to introduce an alkyne handle onto proteins, peptides, and other amine-containing biomolecules through NHS-mediated coupling, enabling downstream click conjugation to azide-bearing partners. Researchers use this reagent to generate clickable bioconjugates for probe assembly, affinity reagent preparation, and multicomponent labeling strategies where a PEG spacer helps reduce aggregation and improves conjugate handling. The resulting alkyne-functional constructs are then compatible with azide-functional dyes, affinity tags, polymers, and nanoparticles for modular build-up of complex research reagents.

2. Surface And Material Functionalization

Propargyl-PEG3-O-C1-NHS ester supports the preparation of alkyne-functional surfaces and biomaterials by reacting with amine groups on coatings, hydrogels, and functionalized substrates. This enables subsequent click attachment of azide-bearing biomolecules, capture ligands, or imaging moieties to create stable, covalently linked interfaces for assay development and materials characterization. The PEG3 spacer contributes to improved surface accessibility of the reactive alkyne, which is particularly valuable when immobilizing probes on crowded or sterically demanding material platforms.

3. Molecular Imaging Probe Building

Propargyl-PEG3-O-C1-NHS ester is commonly employed in the construction of alkyne-tagged imaging reagents, where an NHS coupling step installs the click handle onto targeting scaffolds, tracers, or carrier proteins. After functionalization, CuAAC-compatible conjugation to azide-functional fluorophores or other imaging reporters allows rapid assembly of probe formats with defined linker spacing. This approach is frequently used in molecular imaging and chemical biology workflows to streamline probe generation and to support systematic variation of labeling density and spatial presentation.

4. Diagnostic And Assay Reagent Conjugates

Propargyl-PEG3-O-C1-NHS ester is used to prepare clickable conjugates for diagnostic and analytical assay formats, including reagent components that require covalent attachment to azide-functional reporters or capture elements. By installing an alkyne handle on amine-bearing assay reagents, the workflow enables efficient coupling to azide-tagged detection chemistries, affinity ligands, or signal-generating labels. The PEG3-based linker design helps maintain reagent solubility and reduces nonspecific interactions during assay reagent preparation and storage, supporting reliable downstream conjugation and consistent assay assembly in research and industrial laboratory settings.