Azido-PEG4-(CH2)3OH | CAS 2028281-87-8

Azido-PEG4-(CH2)3OH is a polyethylene glycol (PEG)-based azide building block designed for bioorthogonal click chemistry workflows, most commonly in strain-promoted or copper-catalyzed azide–alkyne cycloaddition (CuAAC) conjugation. Its structure combines a terminal azide handle with a PEG4 spacer and a flexible three-carbon alcohol-bearing tail, enabling robust solubility and convenient downstream functionalization or surface attachment. Researchers and materials developers use this reagent as a modular linker to introduce azide functionality while maintaining chemical flexibility for conjugation to probes, polymers, and biomolecule-derived targeting components.

1. PEG Linker Functionalization

Azido-PEG4-(CH2)3OH is widely used as a PEG spacer to create well-defined, water-compatible linkers for conjugation platforms in chemical biology and biomaterials research. The azide group provides a reliable click handle for installing the PEG chain onto alkyne-bearing partners, while the terminal alcohol-bearing tail supports orthogonal derivatization routes such as further spacer extension, capture chemistry, or polymer-compatible coupling strategies. This design is particularly useful when maintaining colloidal stability and reducing steric constraints are important for downstream probe assembly, coating chemistry, or multi-component construct building.

2. Biomolecule Conjugation Handles

Azido-PEG4-(CH2)3OH serves as a practical azide-tagging reagent for preparing click-ready biomolecule conjugates, including azide-functionalized proteins, peptides, and carbohydrate-bearing constructs used in labeling and assay development. The PEG4 segment helps mitigate aggregation and improves handling in aqueous buffers, which is advantageous for preparing conjugates for imaging reagent development and molecular interaction studies. After azide installation, the reagent’s flexible tethering supports efficient coupling to alkyne-bearing imaging dyes, affinity tags, or reporter scaffolds in typical bioconjugation workflows.

3. Molecular Imaging Probe Assembly

Azido-PEG4-(CH2)3OH is commonly incorporated into molecular imaging probe design as a solubilizing, distance-controlling linker between a click-attachable azide moiety and an alcohol-functional tail for further reagent tailoring. In probe assembly pipelines, the PEG spacer helps tune hydrophilicity and presentation of the reactive handle, which can be critical when constructing fluorescent or luminescent labeling reagents, affinity-based imaging tools, and multi-modal reporter constructs. The reagent’s modularity supports rapid exchange of alkyne-bearing labels, enabling systematic optimization of probe format without redesigning the entire conjugation scaffold.

4. Surface Coating And Materials

Azido-PEG4-(CH2)3OH is used in materials science to introduce azide functionality onto polymer surfaces, hydrogel networks, and coating formulations that are later functionalized via click chemistry. The PEG4 spacer improves compatibility with aqueous processing and can reduce nonspecific interactions in surface-presented systems, while the terminal alcohol-bearing end enables additional material-specific coupling or activation strategies prior to or after azide installation. This makes the reagent a useful component for building clickable material platforms used in biosensing reagent development, immobilized affinity capture surfaces, and modular interfaces for research-grade diagnostic and laboratory automation workflows.