N-(Azido-PEG3)-NH-PEG3-acid | CAS 2183440-72-2

N-(Azido-PEG3)-NH-PEG3-acid is a PEG-based azide functionalized linker designed for copper-free and/or copper-mediated azide–alkyne click conjugation workflows. The reagent combines an azide handle with flexible oligoethylene glycol spacers and a terminal carboxylic acid for straightforward incorporation into biomolecule, polymer, and surface functionalization strategies. Its amphiphilic, hydrophilic PEG architecture is commonly leveraged to improve solubility, reduce nonspecific interactions, and provide a chemically addressable attachment point for downstream probe and material assembly.

1. Antibody And Protein Labeling

N-(Azido-PEG3)-NH-PEG3-acid is widely used in protein labeling pipelines where an azide-bearing handle is required for site-specific or modular conjugation to alkyne-functional partners, including imaging tags, affinity probes, and multivalent detection reagents. The terminal carboxylic acid supports coupling to amine-containing biomolecules or to activated linkers used in bioconjugation platforms, while the PEG spacers help maintain colloidal stability and reduce aggregation during conjugation and storage. Research groups in chemical biology and molecular imaging frequently select this class of reagent to generate well-behaved azide-functional conjugates that can be rapidly extended with reporter payloads via click chemistry.

2. Surface And Material Functionalization

N-(Azido-PEG3)-NH-PEG3-acid is commonly incorporated into surface modification and biomaterials development to introduce azide functionality onto substrates, coatings, and polymer scaffolds. The carboxylic acid enables attachment to activated surfaces or polymer backbones, and the PEG chain length provides steric spacing that can improve accessibility of the azide for subsequent click coupling to immobilized or soluble alkyne reagents. Materials scientists and diagnostic reagent developers use such PEG-azide linkers to build modular assay formats, functionalized membranes, and microfabricated platforms where controlled presentation of reactive sites is important for reproducible probe immobilization.

3. PEGylated Probe And Reagent Building

N-(Azido-PEG3)-NH-PEG3-acid serves as a practical building block for constructing PEGylated chemical probes and reagent conjugates that benefit from reduced nonspecific binding and enhanced aqueous compatibility. The azide group provides a robust click handle for attaching fluorophores, affinity ligands, or signal-generating moieties through established azide–alkyne chemistries, enabling rapid interchange of payloads across a probe series. The PEG spacers also help tune hydrodynamic behavior and presentation of functional groups in solution, which is particularly valuable when developing standardized reagent sets for high-throughput screening, assay optimization, and analytical workflows.

4. Multivalent Assay And Imaging Constructs

N-(Azido-PEG3)-NH-PEG3-acid is frequently used to generate multivalent imaging and detection constructs where flexible spacing and modular assembly are required. By introducing an azide-bearing PEG linker into a larger scaffold, teams can subsequently “click” in multiple alkyne-functional components such as reporters, targeting motifs, or reference tags to create defined architectures for molecular imaging and diagnostic reagent development. The combination of an azide handle and a terminal carboxyl group supports integration into scaffold-forming chemistries, while the PEG environment helps maintain solubility and reduces surface-driven or aggregation-driven artifacts during probe assembly and handling.