3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid | CAS 1429934-37-1

3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid is a polyethylene glycol-like, alkyne-bearing carboxylic acid designed for bioorthogonal click chemistry workflows. As a terminal alkyne reagent, it is commonly used in copper-catalyzed azide–alkyne cycloaddition (CuAAC) to introduce a defined clickable handle onto surfaces, polymers, and biomolecule conjugates. Its extended, ether-rich chain provides aqueous compatibility and spacing that can reduce steric crowding in labeling, coating, and imaging reagent development.

1. Surface And Polymer Labeling

3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid is frequently employed to functionalize polymer backbones and material surfaces with terminal alkyne groups for subsequent CuAAC coupling to azide-tagged probes. Researchers use it to build modular platforms such as clickable hydrogels, PEGylated coatings, and functional polymer brushes where the ether-rich segment helps maintain dispersion and reduces nonspecific interactions during downstream conjugation. The carboxylic acid functionality also supports routine attachment strategies to amine-containing materials or coupling to activated linkers, enabling robust incorporation of the alkyne handle into complex materials used for assay development and molecular display.

2. Bioconjugation For Imaging Probes

3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid is well suited to generate alkyne-functional conjugates that can be rapidly decorated with azide-containing imaging reporters, affinity tags, or enrichment handles via CuAAC. In chemical biology and molecular imaging research, the reagent’s flexible, polyether-like spacing is valuable for maintaining probe accessibility after conjugation, particularly when attaching to proteins, peptides, or targeting ligands that require minimal steric interference. The result is a convenient route to construct clickable probe libraries for fluorescence, luminescence, and other label-based detection formats where consistent handle density and aqueous compatibility are important for reproducible labeling.

3. Diagnostic Reagent Development

3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid supports the construction of diagnostic and analytical reagents that rely on modular assembly of capture and signaling components. Many workflows use alkyne-functional linkers to preinstall a reactive handle on solid supports, bead surfaces, or reagent components, followed by CuAAC coupling to azide-functional antibodies, aptamers, or reporter conjugates. The ether-rich chain helps improve compatibility in buffered assay environments and can contribute to more uniform conjugation spacing, which is particularly useful when building multi-component assay systems such as multiplexing panels, wash-resistant conjugates, and enrichment reagents for analytical workflows.

4. Targeted Ligand And Affinity Tags

3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid is used to introduce a clickable alkyne handle into ligand-based reagents, enabling rapid diversification through azide partners. In biomolecular research and reagent development, the reagent can be incorporated as a linker component to create affinity-tag conjugates, enabling subsequent attachment of secondary modules such as fluorophores, biotin analogs, or affinity-enrichment groups through CuAAC. The combination of a terminal alkyne and a carboxylic acid provides practical design flexibility for preparing clickable ligand constructs that maintain accessibility of the binding moiety while supporting downstream modular assembly for research assays and molecular tool development.