N-(Azido-PEG2)-N-Boc-PEG3-Boc | CAS 2093153-07-0

N-(Azido-PEG2)-N-Boc-PEG3-Boc is a PEG-based azide-bearing click chemistry reagent designed for copper-free and copper-mediated azide–alkyne cycloaddition workflows in chemical biology and materials research. Its structure combines an azide handle with protected amine functionalities (Boc groups) and flexible PEG spacers that improve aqueous compatibility and reduce nonspecific interactions during bioconjugation. This reagent is commonly selected when a linker with controlled spacing, solubility, and orthogonal functional group availability is needed to build functional probes, conjugates, and polymeric materials using azide–alkyne “click” coupling.

1. Biomolecule Conjugation Linker

N-(Azido-PEG2)-N-Boc-PEG3-Boc is widely used as a solubilizing, spacer-containing linker for attaching azide-bearing moieties to alkyne-functional biomolecules, including proteins, peptides, and nucleic-acid probes. The PEG segments help maintain conjugate stability in aqueous buffers and support consistent presentation of the reactive handle for downstream coupling steps. Researchers often incorporate this reagent to introduce a defined distance between a biomolecule and a functional payload, such as a fluorophore, affinity tag, or reactive group, while the Boc-protected amines provide protected functionality during labeling and purification workflows.

2. Fluorophore and Imaging Probe Assembly

N-(Azido-PEG2)-N-Boc-PEG3-Boc is commonly used in molecular imaging and assay reagent development to generate azide-functional intermediates for attaching imaging reporters to alkyne-modified scaffolds. The flexible PEG architecture supports water-friendly probe construction and can reduce aggregation that sometimes complicates labeling of hydrophobic dyes and bulky reporter conjugates. In probe development pipelines, the reagent’s azide handle enables modular “click” attachment to a wide variety of alkyne-bearing imaging components, while the Boc groups allow compatibility with multi-step synthesis strategies where amine reactivity must be managed until later stages.

3. Surface and Materials Functionalization

N-(Azido-PEG2)-N-Boc-PEG3-Boc is used to functionalize polymer surfaces, nanoparticles, and biomaterial interfaces that require controlled linker spacing for subsequent click coupling. The PEG-rich backbone improves dispersion and minimizes surface fouling, which is valuable when preparing sensor surfaces, coating layers, and functionalized composite materials for research-grade assays. By providing an azide functional group, the reagent supports straightforward attachment to alkyne-bearing surface chemistries, enabling reproducible incorporation of reactive sites or recognition elements into materials platforms.

4. Diagnostic Reagent and Assay Platforms

N-(Azido-PEG2)-N-Boc-PEG3-Boc is frequently incorporated into diagnostic reagent development for constructing modular assay components that rely on azide–alkyne coupling to assemble complex labeling schemes. Linker control is particularly important in multiplexed assay workflows where spacing and solubility influence reagent handling, conjugate stability, and signal-background behavior. The PEG spacer helps maintain reagent compatibility across common assay buffers, while the protected amine functionality supports stepwise synthesis of intermediates that can be further functionalized after click assembly.