Azido-PEG3-C3-OH | CAS 1807512-36-2

Azido-PEG3-C3-OH is a PEG-based azide building block designed for bioorthogonal click chemistry, most commonly used in strain-promoted or copper-catalyzed azide–alkyne cycloaddition workflows. The reagent combines a terminal azide handle with a short PEG spacer and a carboxyl-functionalized propyl segment, enabling attachment to biomolecules, surfaces, and polymers while maintaining improved solubility and reduced steric hindrance. Its flexible, water-compatible linker architecture makes it a practical choice for downstream conjugation and labeling strategies in chemical biology, biomaterials, and molecular imaging reagent development.

1. Biomolecule Conjugation Linker

Azido-PEG3-C3-OH is widely used as a soluble azide linker for preparing functionalized proteins, peptides, and other biomolecular constructs that require a defined clickable handle. The PEG3 segment helps maintain aqueous compatibility and spacing between the azide and the conjugated scaffold, which is beneficial when bulky targeting ligands or fluorophores are introduced later via click coupling. The terminal carboxyl group supports common coupling workflows to install the linker onto amine-bearing biomolecules or onto activated surfaces, after which the azide can be used to connect to alkyne-functional partners for labeling, probe assembly, or multicomponent construct generation.

2. Surface And Material Functionalization

Azido-PEG3-C3-OH is used in biomaterials and surface chemistry to introduce azide functionality onto polymers, coatings, and functionalized substrates for subsequent click-based patterning. The combination of a PEG spacer and a carboxyl terminus supports tethering strategies that yield stable, water-friendly surface presentation while preserving accessibility of the azide group for later reaction with alkyne-bearing reagents. This approach is commonly adopted in materials research where modular assembly is needed, such as creating clickable hydrogel components, functional polymer brushes, or azide-functional interfaces that can be rapidly decorated with imaging probes, affinity tags, or other chemical motifs.

3. Molecular Imaging Probe Assembly

Azido-PEG3-C3-OH serves as a practical intermediate for building molecular imaging and detection reagents that rely on modular click conjugation. Researchers often use the carboxyl functionality to integrate the linker into carrier scaffolds or targeting vectors, while the azide handle enables efficient coupling to alkyne-functional dyes, reporter groups, or imaging moieties under bioorthogonal conditions. The PEG3 spacing is particularly helpful for maintaining solubility and improving the effective presentation of the clickable site, which can be important when assembling multicomponent probes designed for robust labeling workflows in chemical biology laboratories.

4. Diagnostic Reagent Development

Azido-PEG3-C3-OH is utilized in the development of diagnostic and assay reagents that benefit from orthogonal, high-yield conjugation steps during reagent construction. The azide group provides a reliable chemical handle for click coupling to alkyne-functional reporters, capture elements, or signal-generating components, enabling streamlined assembly of complex assay formats without extensive intermediate purification. The PEG3–C3–carboxyl architecture supports integration into reagent platforms where aqueous handling and controlled linker length are important, including clickable labeling of affinity reagents, preparation of multivalent binding constructs, and fabrication of probe-functional materials used in analytical workflows.