Propargyl-PEG7-NHS ester | CAS 2093152-77-1

Propargyl-PEG7-NHS ester is a PEG-based NHS ester functionalized with a terminal alkyne, designed for copper-free or copper-mediated click chemistry workflows after amide coupling to primary amines. As a click-compatible bioconjugation handle, the long PEG spacer improves solubility and reduces nonspecific interactions, while the NHS ester enables efficient attachment to proteins, peptides, and other amine-bearing biomolecules. This reagent is widely used to generate alkyne-functional conjugates that subsequently participate in azide–alkyne cycloaddition for labeling, surface patterning, and modular probe assembly in chemical biology and biomaterials research.

1. Protein And Peptide Labeling

Propargyl-PEG7-NHS ester is commonly used to functionalize proteins and peptides with a terminal alkyne for downstream click labeling with azide-bearing dyes, affinity tags, or reporter groups. The NHS ester chemistry supports straightforward conjugation to lysine residues under typical bioconjugation conditions, and the PEG7 spacer helps maintain aqueous compatibility and can moderate steric effects that otherwise limit labeling density. Researchers use the resulting alkyne-modified biomolecules to build site-defined or semi-random fluorescent conjugates, imaging reagents, and tool constructs for studying biomolecular interactions.

2. Surface Coatings And Materials

Propargyl-PEG7-NHS ester is applied to introduce click-reactive alkyne groups onto amine-presenting material surfaces, enabling subsequent azide–alkyne coupling for immobilization and patterning. This approach is frequently adopted in biomaterials science to create functional coatings on polymeric substrates, hydrogel interfaces, and other amine-functionalized surfaces where PEG spacing can improve hydration and reduce nonspecific adsorption. Alkyne-bearing surfaces generated from this reagent serve as platforms for attaching bioactive ligands, capture probes, or fluorescent reporters via modular click chemistry steps.

3. Molecular Imaging Probe Assembly

Propargyl-PEG7-NHS ester supports the preparation of alkyne-functional targeting or imaging components that can be assembled into multicomponent probes using azide-functional partners. The PEG spacer is particularly useful when constructing conjugates that need to remain soluble and accessible for labeling, helping to preserve the performance of sensitive reporter moieties during probe assembly. In molecular imaging and diagnostic reagent development workflows, this reagent is used to create click-ready intermediates that can be rapidly combined with azide-tagged dyes, nanoparticles, or imaging scaffolds to generate defined probe formats.

4. Diagnostic Reagent And Assay Platforms

Propargyl-PEG7-NHS ester is used to generate alkyne-functional reagents for assay development, including conjugates that are subsequently linked to azide-functional detection elements. By installing an alkyne handle onto amine-containing biomolecules, researchers can perform modular click coupling to attach readout components such as fluorophores, enzyme labels, or affinity reagents in a controlled, workflow-friendly manner. The PEG7-based design helps reduce aggregation and supports reproducible conjugate behavior across assay formats, making it a practical choice for building flexible diagnostic reagent components and screening tools.