Azido-PEG1-t-butyl ester | CAS 1374658-85-1

Azido-PEG1-t-butyl ester is a PEGylated azide building block designed for click chemistry workflows, most commonly serving as an azide partner for strain-promoted or CuAAC bioconjugation strategies. The short PEG spacer and protected carboxyl functionality enable convenient incorporation into labeling, surface modification, and probe construction while improving aqueous handling and minimizing nonspecific hydrophobic interactions. Its compact structure makes it well suited for generating defined PEG-linked handles in molecular imaging reagents, affinity probes, and biomaterials functionalization where controlled attachment chemistry is required.

1. PEG Linker For Conjugates

Azido-PEG1-t-butyl ester is widely used as a compact PEG linker precursor for preparing azide-functional conjugates in chemical biology and analytical chemistry. Researchers incorporate the azide handle to enable downstream click ligation to cyclooctyne or strained alkyne partners, allowing modular assembly of fluorescent probes, affinity tags, and detection reagents. The PEG spacer supports improved solubility and reduced aggregation compared with non-PEG linkers, which is particularly valuable when constructing water-compatible labeling reagents for assays and platform studies. The t-butyl ester functionality provides a protected carboxyl group that can be leveraged during reagent design to control when the acidic functionality is revealed or used for subsequent coupling steps in multistep workflows.

2. Surface And Material Functionalization

Azido-PEG1-t-butyl ester is used to introduce azide functionality onto material surfaces and polymeric scaffolds for subsequent click-based immobilization. In biomaterials science, the reagent supports the creation of defined reactive interfaces for attaching biomolecules, capture ligands, or imaging components through orthogonal click chemistry. The short PEG segment helps mitigate steric crowding at the surface and can improve accessibility of the azide for efficient coupling to complementary clickable partners. This makes the reagent a practical choice for preparing functionalized coatings, hydrogel components, and resin-bound intermediates used in research-grade immobilization and assay development.

3. Molecular Imaging Probe Assembly

Azido-PEG1-t-butyl ester is commonly selected for building modular molecular imaging and detection probes that require a robust azide handle for late-stage conjugation. Probe developers use the azide functionality to couple imaging moieties, targeting ligands, or reporter groups using click chemistry, enabling rapid interchange of components without redesigning the entire scaffold. The PEG1 spacer contributes to aqueous compatibility and can help maintain favorable probe behavior in labeling and purification steps typical of imaging reagent workflows. The protected ester group also aligns with reagent design strategies where functional group availability is managed across sequential coupling and purification operations.

4. Affinity Reagent And Tagging

Azido-PEG1-t-butyl ester is applied in the preparation of affinity reagents and tagged research tools where controlled attachment chemistry is essential. By providing a defined azide handle, the reagent enables click-based conjugation of antibodies, peptides, binders, or polymeric carriers to reporter groups and solid supports. The PEG spacer supports improved solubility and can reduce nonspecific interactions during labeling and washing steps, which is important for reproducible signal generation in platform experiments. The t-butyl ester functionality supports multistep synthesis planning for generating conjugates with the desired functional group presentation for subsequent coupling or immobilization steps.