Propargyl-PEG3-acid | CAS 1347760-82-0

Propargyl-PEG3-acid is a PEG-based alkyne building block featuring a terminal propargyl group for copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry and a carboxylic acid handle for conjugation and surface attachment. Its short, flexible PEG spacer improves aqueous compatibility and reduces steric constraints during bioconjugation workflows. This reagent is commonly used as a functional linker to introduce a defined alkyne moiety into probes, biomaterials, and imaging or diagnostic reagents that rely on subsequent azide-tagged partners.

1. Bioconjugation Linker Use

Propargyl-PEG3-acid is widely used to install an alkyne functional handle on biomolecules and affinity reagents prior to CuAAC coupling with azide-bearing targets. The carboxylic acid enables straightforward incorporation into amide-forming or coupling strategies used in labeling workflows, while the PEG3 spacer helps maintain reactivity in aqueous buffers. Researchers frequently select this reagent when they need a compact, water-compatible tether that supports efficient downstream click attachment to azide-functional dyes, peptides, proteins, or carbohydrate tags.

2. Surface And Material Functionalization

Propargyl-PEG3-acid supports the preparation of alkyne-functional surfaces and polymeric materials for patterned or modular assembly via click chemistry. The carboxylic acid group provides a practical anchoring point for immobilization strategies on activated surfaces or material coatings, and the terminal propargyl alkyne serves as the reactive site for subsequent coupling to azide-functional biomolecules. This approach is commonly applied in biomaterials science to create reactive interfaces for immobilized ligands, cell-interaction studies, and modular material architectures where orthogonal attachment is advantageous.

3. Molecular Imaging Probe Assembly

Propargyl-PEG3-acid is used as an intermediate linker to generate alkyne-bearing imaging probes that can be assembled by CuAAC with azide-functional fluorophores or reporter constructs. The PEG3 segment helps maintain probe solubility and reduces nonspecific interactions in labeling and probe preparation workflows, which is particularly valuable when conjugates are prepared in complex labeling buffers. Imaging-focused research groups often rely on this reagent to standardize the location of the click handle, enabling consistent probe-to-reporter coupling across different batches and labeling targets.

4. Diagnostic Reagent And Assay Building

Propargyl-PEG3-acid is a practical component for constructing diagnostic and assay reagents that require modular attachment of detection elements through click chemistry. By providing a defined alkyne handle and a carboxylic acid for incorporation into reagent platforms, it supports the preparation of conjugates used in binding assays, affinity workflows, and multicomponent assay formats. Many assay developers use this reagent to streamline the integration of azide-functional reporters or capture reagents, improving compatibility with automated conjugation pipelines and enabling flexible reagent design.