Azido-PEG4-amido-tri-(carboxyethoxymethyl)-methane | CAS 1398044-51-3

Azido-PEG4-amido-tri-(carboxyethoxymethyl)-methane is a PEG-based azide click chemistry reagent designed for copper-catalyzed azide–alkyne cycloaddition (CuAAC) and related azide-driven bioconjugation workflows. The scaffold combines an azide functional group with a flexible PEG4 spacer and an amide-linked tri-(carboxyethoxymethyl)-methane motif, providing multiple carboxylate handles for downstream aqueous coupling and conjugate formulation. This combination is commonly leveraged in molecular imaging probe construction, polymer and biomaterial functionalization, and multivalent labeling strategies where solubility, spacing control, and orthogonal reactivity are important.

1. Multivalent Biomolecule Labeling

Azido-PEG4-amido-tri-(carboxyethoxymethyl)-methane is used to introduce azide functionality into proteins, peptides, and nucleic-acid binding reagents while maintaining water solubility through the PEG4 spacer. The tri-(carboxyethoxymethyl)-methane carboxylate-rich region supports subsequent derivatization steps that are frequently required for linking to carrier scaffolds, affinity tags, or secondary functional groups used in labeling workflows. Researchers often select this reagent when they need multivalent spacing to improve conjugate uniformity and to reduce steric crowding during downstream CuAAC coupling to alkyne-bearing reporters.

2. Surface and Hydrogel Functionalization

Azido-PEG4-amido-tri-(carboxyethoxymethyl)-methane supports the preparation of azide-functional surfaces and soft materials by enabling incorporation of click-ready azide groups into polymer networks and hydrogel matrices. The presence of multiple carboxylate sites facilitates coupling to amine- or activated-surface chemistries used in materials science toolkits, while the PEG spacer helps maintain accessibility of the azide for later reaction with alkyne-modified ligands, dyes, or biomolecules. This approach is widely adopted in biomaterials laboratories that build modular, post-functionalized materials for imaging, assay development, and extracellular-mimetic studies.

3. Molecular Imaging Probe Construction

Azido-PEG4-amido-tri-(carboxyethoxymethyl)-methane is commonly incorporated into imaging-reagent pipelines to provide a stable azide handle for subsequent CuAAC attachment of fluorophores, affinity motifs, or other imaging components bearing terminal alkynes. The PEG4 segment supports aqueous compatibility and helps preserve probe performance in labeling buffers, while the carboxylate-rich motif can be useful for tuning solubility and for coordinating additional conjugation steps that are often required when assembling multi-component probes. Probe developers frequently rely on this reagent to standardize azide loading and spacing, enabling consistent downstream attachment of imaging reporters across different targeting constructs.

4. Diagnostic and Assay Reagent Platforms

Azido-PEG4-amido-tri-(carboxyethoxymethyl)-methane is used to build click-compatible assay reagents where controlled attachment of detection elements is required. The azide group enables efficient coupling to alkyne-functional reporters used in fluorescence-based assays, bead-based workflows, and surface-tethered detection formats, while the PEG spacer helps reduce nonspecific interactions that can arise from overly hydrophobic linkers. In diagnostic reagent development contexts, the tri-carboxylate motif also provides convenient chemical handles for integrating the reagent into larger assay architectures that require multiple connection points or subsequent functionalization steps.