Azide-PEG2-iodide | CAS 2387581-33-9

Azide-PEG2-iodide is a bifunctional PEG-based click chemistry reagent combining an azide handle with a terminal iodide for orthogonal conjugation workflows. As an azide-bearing partner, it is widely used in copper-catalyzed azide–alkyne cycloaddition (CuAAC) and related strain-promoted azide chemistry to install biomolecules, probes, or materials with high modularity. The short PEG spacer and iodide functionality make it particularly relevant for preparing intermediate conjugates and for downstream labeling strategies where controlled attachment points and flexible solubility are required.

1. Bioconjugation Labeling

Azide-PEG2-iodide is commonly used to introduce a defined azide functionality into labeling and conjugation pipelines, enabling subsequent attachment of alkynes through CuAAC to generate stable triazole-linked bioconjugates. Researchers use the PEG spacer to reduce steric constraints during probe assembly and to improve handling in aqueous labeling buffers. The iodide-bearing end can be leveraged as a complementary reactive group during intermediate preparation steps, supporting workflows where an azide-tagged construct must be generated before final installation of fluorophores, affinity ligands, or other imaging/analysis components.

2. Molecular Imaging Probes

Azide-PEG2-iodide is frequently incorporated into the synthesis of modular imaging reagents, where an azide handle provides a reliable coupling point for attaching imaging reporters via click chemistry. Molecular imaging and chemical biology laboratories value the orthogonality of the azide group for late-stage probe diversification, allowing rapid exchange of targeting motifs or reporter moieties without redesigning the entire scaffold. The PEG2 segment helps maintain probe solubility and reduces nonspecific aggregation during probe formulation and characterization, which is important for consistent performance in in vitro assay settings and imaging reagent development.

3. Surface And Material Functionalization

Azide-PEG2-iodide is used to functionalize surfaces and biomaterials with azide groups that can be patterned or coupled to alkyne-functional coatings through click reactions. Materials scientists and biomaterials groups often choose PEG-based linkers to improve surface accessibility of reactive sites and to tune interfacial hydrophilicity, which can influence subsequent conjugation efficiency and stability. After installing azide functionality, the material can be further decorated with alkynes to create immobilized sensors, patterned assay platforms, or clickable polymer/biopolymer assemblies for research-grade material studies.

4. Diagnostic Reagent Development

Azide-PEG2-iodide supports diagnostic reagent and assay-development workflows that rely on modular reagent assembly, where an azide moiety serves as a standardized attachment point for downstream conjugation. In chemical biology and diagnostics R&D settings, the reagent is used to prepare clickable intermediates that can be coupled to detection elements such as enzyme tags, affinity reagents, or signal-generating reporters through azide–alkyne cycloaddition. The PEG2 linker helps maintain reagent solubility and reduces steric hindrance during conjugate construction, facilitating reproducible preparation of assay components and enabling efficient optimization of labeling density and reagent architecture.