N-(Azido-PEG3)-N-Boc-PEG4-Boc | CAS 2112731-94-7

N-(Azido-PEG3)-N-Boc-PEG4-Boc is a PEG-based azide-functional click chemistry reagent designed for bioorthogonal conjugation workflows. As an azide-bearing, protected PEG scaffold, it is commonly used in strain-promoted or copper-catalyzed azide–alkyne cycloaddition (CuAAC) strategies to install PEG spacers onto biomolecules, surfaces, or materials. The presence of Boc-protected functionalities and the extended PEG architecture make it particularly relevant for building soluble, sterically shielded conjugates and for tuning hydrophilicity and spacing in molecular imaging and diagnostic reagent development.

1. PEGylated Biomolecule Labeling

N-(Azido-PEG3)-N-Boc-PEG4-Boc is used to generate PEGylated biomolecule conjugates where improved solubility, reduced nonspecific interactions, and controlled linker length are desired. Researchers commonly incorporate this reagent into labeling pipelines for antibodies, antibody fragments, peptides, and enzyme-binding ligands, enabling attachment of PEG spacers through azide–alkyne click chemistry to downstream imaging handles or affinity tags. The PEG-rich structure supports stable conjugate formats for assay development and reagent storage, while the azide functionality provides a reliable orthogonal handle for modular assembly with complementary alkyne-bearing partners.

2. Surface and Material Functionalization

N-(Azido-PEG3)-N-Boc-PEG4-Boc is well suited for modifying polymeric and hydrogel surfaces with click-reactive PEG linkers to control surface hydration and reduce background signal in analytical formats. Materials scientists and diagnostic reagent developers use the azide group to couple PEG spacers onto alkyne-functional coatings, nanoparticles, or device surfaces, supporting reproducible immobilization of capture molecules and improved accessibility of binding sites. The extended PEG chain architecture is frequently leveraged to tune interfacial properties, helping create more uniform conjugation layers for biosensing platforms and research-grade material toolkits.

3. Molecular Imaging Probe Construction

N-(Azido-PEG3)-N-Boc-PEG4-Boc supports the modular construction of molecular imaging probes by serving as a PEG linker precursor that can be clicked to alkyne-functional imaging moieties or reporter scaffolds. In probe development workflows, the reagent is used to place hydrophilic PEG spacers between targeting biomolecules and imaging labels, which can help manage probe distribution characteristics and reduce aggregation tendencies during formulation and handling. The azide handle enables straightforward late-stage assembly, allowing imaging teams to rapidly exchange reporter components while maintaining consistent linker geometry across probe libraries.

4. Diagnostic Reagent and Assay Linkers

N-(Azido-PEG3)-N-Boc-PEG4-Boc is used in diagnostic reagent development to create defined PEG-based linkers that improve assay robustness and conjugate stability. Assay developers and chemical biology teams incorporate this azide-bearing PEG scaffold into click-assembled reagent constructs, such as labeling reagents for immunoassays, affinity capture reagents, and multiplexing components where controlled spacing is important for signal-to-background performance. By providing a modular azide functionality, the reagent integrates into workflows that require consistent linker length and hydrophilic surface presentation across batches, supporting reproducible reagent assembly for research and industrial assay development.