Azido-PEG2-t-butyl ester | CAS 1271728-79-0

Azido-PEG2-t-butyl ester is a small-molecule azide functionalized with a short polyethylene glycol (PEG) spacer and a tert-butyl ester handle, making it well suited for bioorthogonal click chemistry workflows. As an azide-bearing reagent, it is commonly used as the complementary partner for strain-promoted or copper-catalyzed azide–alkyne cycloaddition to install PEGylated motifs onto biomolecules, surfaces, and polymeric scaffolds. The compact PEG2 length supports improved solubility and reduced nonspecific interactions, while the tert-butyl ester provides an orthogonal chemical handle that can be leveraged during conjugate construction and downstream processing.

1. Surface PEG Functionalization

Azido-PEG2-t-butyl ester is frequently used to introduce PEG spacers onto material surfaces where azide–alkyne click conjugation enables rapid, modular coating strategies. Researchers apply it to functionalize glass, polymer films, and nanoparticle interfaces with PEG-bearing linkers that help control protein adsorption and improve colloidal stability during imaging or assay development. The short PEG2 segment is particularly attractive when a minimal yet effective hydrophilic layer is needed to preserve accessibility of other functional groups on the same platform.

2. Biomolecule Labeling Probes

Azido-PEG2-t-butyl ester supports the construction of PEGylated labeling reagents for chemical biology studies, where azide handles are used to attach probes to biomolecular targets via click chemistry. In practice, it is incorporated into probe design to tune solubility, spacing, and steric presentation of the conjugated moiety, which can be important when generating consistent labeling density on proteins, peptides, or nucleic-acid-associated constructs. The tert-butyl ester functionality also aligns with workflows that require an additional chemical handle for processing steps during probe assembly.

3. Imaging and Diagnostic Reagent Platforms

Azido-PEG2-t-butyl ester is commonly used in molecular imaging and diagnostic reagent development as a linker component that enables attachment of detection chemistries to carriers or scaffolds through azide–alkyne cycloaddition. The PEG2 spacer helps maintain favorable aqueous behavior and reduces aggregation tendencies in multicomponent probe mixtures, which is valuable when assembling conjugates that include dyes, affinity ligands, or other reporter functionalities. By providing a defined azide-bearing attachment point, it streamlines the integration of reporter-bearing building blocks into standardized reagent formats.

4. Polymer and Hydrogel Conjugation

Azido-PEG2-t-butyl ester is applied in polymer science and biomaterials research to incorporate PEGylated linkers into macromolecular networks using click-based conjugation strategies. It can be used to modify polymer backbones, crosslinker systems, or hydrogel components to adjust hydrophilicity, diffusion characteristics, and overall material compatibility with biochemical assays. The reagent’s compact structure and azide functionality make it a practical choice for building modular conjugation schemes where PEG spacing is used to tune material performance in research-grade experimental platforms.