Alkyne-PEG4-iodide | CAS 1383528-70-8

Alkyne-PEG4-iodide is an alkyne-functionalized, PEG-based alkyl iodide designed for click chemistry workflows that combine efficient bioorthogonal conjugation with convenient handle installation. As a substrate for copper-catalyzed azide–alkyne cycloaddition (CuAAC), the terminal alkyne enables robust attachment of biomolecules, polymers, and surfaces to azide-bearing partners. The PEG4 spacer and iodide leaving group make it broadly useful for preparing PEGylated linkers, radiolabeling/iodination-related intermediate strategies, and downstream conjugation platforms in chemical biology and materials research.

1. PEG Linker Bioconjugation

Alkyne-PEG4-iodide is widely used as a PEGylated tether in bioconjugation pipelines where a flexible, hydrophilic spacer is needed to reduce steric constraints and improve conjugate solubility. Researchers incorporate the alkyne handle to connect PEGylated scaffolds to azide-functional biomolecules, including affinity reagents, targeting ligands, and labeling constructs used in cellular and biochemical assays. The iodide functionality also supports practical intermediate preparation for installing the PEG linker onto other reactive substrates before proceeding to CuAAC-based assembly.

2. Surface And Material Functionalization

Alkyne-PEG4-iodide is commonly selected for modifying polymeric materials and engineered surfaces with click-ready alkynes that can be patterned or assembled with azide-bearing coatings. In biomaterials science, PEG spacers help maintain surface wettability and reduce nonspecific interactions, which is valuable for creating stable functional interfaces for biosensing, affinity capture, and scaffold engineering. The reagent’s alkyne group enables modular coupling to azide-functional polymers, peptides, or capture ligands, allowing rapid generation of libraries of surface chemistries without extensive redesign of the underlying material.

3. Molecular Imaging Probe Assembly

Alkyne-PEG4-iodide is used as a linker component in the construction of molecular imaging and labeling probes where controlled spacing between a reactive moiety and a bioorthogonal attachment site is important. Probe developers often rely on the alkyne handle to connect to azide-bearing reporter elements, enabling consistent conjugation strategies across different imaging modalities and targeting formats used in research settings. The PEG4 segment supports improved dispersion and reduced aggregation of probe conjugates, which can be advantageous when preparing multi-component labeling reagents for imaging workflows.

4. Diagnostic Reagent And Assay Labeling

Alkyne-PEG4-iodide supports the preparation of assay reagents that require standardized click-compatible labeling chemistry, particularly when PEGylation is used to tune reagent behavior in complex assay buffers. Diagnostic reagent developers and chemical biology teams use the alkyne functionality to attach azide-functional reporters, affinity tags, or capture elements in a modular fashion, facilitating the rapid interchange of labeling components. By providing a PEG4 spacer, Alkyne-PEG4-iodide helps maintain accessibility of the conjugated reporter and supports reproducible reagent formatting for downstream assay development.