N-(Azido-PEG2)-N-Boc-PEG4-acid | CAS 2093153-82-1

N-(Azido-PEG2)-N-Boc-PEG4-acid is a PEG-based azide-functionalized click chemistry reagent designed for bioorthogonal conjugation workflows. As an azide handle compatible with strain-promoted or copper-catalyzed azide–alkyne cycloaddition (depending on the partner), it provides a flexible, hydrophilic spacer that helps minimize steric constraints during labeling and surface modification. The presence of a protected amine (Boc) and a terminal carboxylic acid makes the scaffold particularly useful for building conjugates, attaching linkers to biomolecules, and preparing imaging or materials platforms where controlled spacing is critical.

1. Biomolecule Labeling Linkers

N-(Azido-PEG2)-N-Boc-PEG4-acid is commonly used as a distance-controlled linker for attaching azide functionality to peptides, proteins, and nucleic-acid bearing constructs prior to downstream click conjugation. The PEG segments improve solubility and reduce nonspecific interactions during labeling, which is valuable for preparing homogeneous probe sets for biochemical assays and molecular interaction studies. The terminal carboxylic acid enables straightforward coupling to amine-containing targets, while the azide group serves as the reactive handle for subsequent attachment to alkyne-functional dyes, affinity tags, or imaging reporters.

2. Surface Functionalization Chemistry

N-(Azido-PEG2)-N-Boc-PEG4-acid supports azide installation on material surfaces used in biosensing and analytical platforms, where PEG spacing helps preserve accessibility of the reactive group. Researchers often use the carboxylic acid functionality to anchor the reagent to activated surfaces or polymer backbones, generating stable, water-compatible azide-presenting interfaces. After surface installation, the azide handle enables patterned or modular attachment of alkyne-bearing components, facilitating the assembly of multiplexed capture surfaces and customizable diagnostic reagent formats.

3. Molecular Imaging Probe Assembly

N-(Azido-PEG2)-N-Boc-PEG4-acid is frequently incorporated into probe-building pipelines to introduce an azide-bearing PEG spacer that improves conjugate behavior in aqueous imaging workflows. The reagent’s flexible architecture helps maintain effective separation between the imaging moiety and the targeting or recognition element, which can be important when constructing fluorescent, luminescent, or other label-bearing reporters. By serving as an intermediate linker, it allows teams to standardize azide installation across probe families and then rapidly diversify the final imaging constructs using alkyne partner reagents.

4. PEGylated Conjugate Platforms

N-(Azido-PEG2)-N-Boc-PEG4-acid is well suited for creating PEGylated conjugate platforms where hydrophilicity and steric shielding are desired to improve handling and reduce aggregation during reagent preparation. The PEG-rich structure provides a tunable spacing element that can be leveraged when building multicomponent conjugates, such as multi-label research reagents or modular reagent cartridges for automated workflows. The azide group enables later click attachment to complementary partners, allowing researchers to decouple azide installation from final assembly and maintain consistent linker chemistry across experimental batches.