N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) | CAS 2086689-00-9

N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) is an azide-functionalized, PEG-based click chemistry reagent designed for copper-free and/or copper-catalyzed azide–alkyne cycloaddition workflows in chemical biology and materials research. Its structure combines an azide handle for bioorthogonal conjugation with PEG spacers that improve solubility and reduce nonspecific interactions, while the t-butyl ester groups provide chemically addressable ester functionality for downstream derivatization or controlled reactivity. This reagent is commonly used as a modular linker to build PEGylated conjugates, functional probes, and surface- or particle-associated constructs where reliable azide presentation and aqueous compatibility are essential.

1. PEGylated Bioconjugation Handles

N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) is widely used as a PEGylation scaffold for preparing azide-bearing conjugation intermediates used in protein labeling, polymer conjugation, and multicomponent biomolecular assembly. Researchers value the PEG3 spacing for maintaining accessibility of the azide group and for improving the colloidal stability of conjugates in aqueous buffers, which is particularly relevant when attaching bulky targeting ligands, imaging tags, or affinity reagents. The bis(PEG1-t-butyl ester) motif supports further functionalization steps that can be used to tune hydrophilicity, introduce additional chemical handles, or enable orthogonal coupling strategies after the click step.

2. Surface And Nanoparticle Functionalization

N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) is employed to introduce azide functionality onto surfaces and particle platforms used in chemical biology tool development and biomaterials research. In workflows for coating nanoparticles, modifying porous materials, or functionalizing polymeric supports, the PEG architecture helps promote uniform presentation of reactive sites and can reduce aggregation during conjugation. After azide installation, downstream click reactions with alkyne-bearing ligands enable rapid generation of multivalent coatings for affinity capture, assay reagent construction, or modular assembly of probe-rich materials. The t-butyl ester groups also offer a practical route for subsequent chemical addressing when additional derivatization is required for surface chemistry optimization.

3. Molecular Imaging Probe Construction

N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) serves as a practical building block for constructing imaging and detection probes that require controlled PEG spacing between a reactive handle and a reporter moiety. Teams developing fluorescent, luminescent, or mass-tagged probe conjugates often rely on azide–alkyne click chemistry to couple the PEG linker to reporters, targeting groups, or enrichment handles under conditions compatible with sensitive labeling reagents. The reagent’s PEG-based design supports aqueous conjugate handling and helps maintain probe solubility during labeling and purification. By providing an azide handle with additional ester functionality for later modification, it fits into iterative probe development pipelines where linker properties are tuned to balance reactivity, stability, and labeling efficiency.

4. Diagnostic Reagent And Assay Platforms

N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) is used to prepare azide-functional assay components for diagnostic reagent development and analytical workflow optimization in research settings. In assay platform construction, azide-bearing PEG linkers support modular attachment of recognition elements, signal reporters, and capture chemistries through click-compatible coupling partners, enabling consistent reagent assembly across different target classes. The PEG spacers help minimize steric hindrance and nonspecific adsorption, which is important when integrating conjugates into microplate formats, bead-based assays, or surface-tethered detection systems. The bis(PEG1-t-butyl ester) functionality can be leveraged to generate additional reactive derivatives for coupling to assay matrices or to adjust the chemical environment of the final reagent construct.

5. Polymer And Hydrogel Crosslinking Design

N-(Azido-PEG3)-N-bis(PEG1-t-butyl ester) is applied in polymer chemistry and biomaterials engineering to incorporate azide functionality into PEG-containing networks and functional hydrogels used as research tools. Materials scientists use the reagent to introduce click-reactive sites that can be coupled with alkyne-functional crosslinkers, bioactive motifs, or imaging-compatible reporters to create modular, chemically defined constructs. The PEG-rich structure supports water compatibility and can contribute to network homogeneity by improving dispersion of reactive components during gel formation or post-functionalization. The presence of t-butyl ester groups provides additional chemical addressability for tailoring the material’s subsequent functionalization steps without disrupting the azide handle needed for click-based assembly.