N-(Azido-PEG3)-N-bis(PEG4-acid) | CAS 2112731-54-9

N-(Azido-PEG3)-N-bis(PEG4-acid) is a PEG-based azide click chemistry reagent designed for robust bioconjugation workflows. As an azide functional handle, it is commonly used in strain-promoted or copper-catalyzed azide–alkyne cycloaddition (CuAAC) to attach biomolecules, targeting ligands, or imaging tags to surfaces and macromolecular scaffolds. The reagent combines a short PEG spacer (PEG3) with two PEG4-acid termini, providing both aqueous compatibility and carboxylate functionality that can support downstream coupling chemistries for modular probe and material construction.

1. Biomolecule PEGylation Platforms

N-(Azido-PEG3)-N-bis(PEG4-acid) is frequently incorporated into PEGylation and linker architectures for preparing functional bioconjugates where solubility and spacing are critical. Researchers use the azide group as a standardized click handle to install the PEG-containing linker onto alkyne-bearing proteins, peptides, or affinity reagents, enabling controlled presentation of additional reactive groups. The dual PEG4-acid motif supports further conjugation strategies that benefit from multivalent spacing, such as attaching secondary ligands, affinity tags, or capture moieties to create modular assay reagents and research-grade molecular tools.

2. Surface and Hydrogel Functionalization

N-(Azido-PEG3)-N-bis(PEG4-acid) is well suited for functionalizing biomaterial surfaces and hydrogel matrices that require stable, water-compatible linkers for subsequent click attachment. In materials laboratories, the reagent is used to introduce azide functionality into polymer networks or coated substrates, allowing later coupling to alkyne-modified components such as fluorescent reporters, bioactive peptides, or recognition elements. The PEG-rich structure helps minimize nonspecific interactions and supports uniform coating or network incorporation, while the carboxylate ends provide additional handles for orthogonal coupling and material tuning during probe or scaffold assembly.

3. Molecular Imaging Probe Building

N-(Azido-PEG3)-N-bis(PEG4-acid) is commonly used in molecular imaging and diagnostic reagent development pipelines to assemble imaging probes with improved aqueous handling and controlled linker length. Probe developers employ the azide moiety to click-connect alkyne-functional fluorophores, chelator-bearing groups, or reporter scaffolds to targeting or distribution elements. The PEG4-acid termini are valuable for constructing multi-step probe architectures where additional coupling to carrier proteins, nanoparticles, or assay surfaces is needed, supporting reproducible conjugate design for research imaging workflows.

4. Diagnostic Assay Reagent Conjugates

N-(Azido-PEG3)-N-bis(PEG4-acid) supports the preparation of diagnostic assay reagents that rely on modular conjugation and consistent linker spacing. Assay development teams use the azide functionality to couple standardized PEG-based linkers to alkyne-bearing detection components, including enzyme labels, affinity reagents, or oligonucleotide conjugate formats used in research diagnostics. The presence of PEG4-acid groups enables further derivatization steps that integrate the conjugate into assay formats such as bead-based workflows, coated plate systems, or lateral-flow-style reagent assemblies, where controllable chemistry and minimized background are important for reliable reagent construction.