N-(Azido-PEG4)-N-bis(PEG4-t-butyl ester) | CAS 2093152-79-3

N-(Azido-PEG4)-N-bis(PEG4-t-butyl ester) is a PEG-based azide click chemistry reagent designed for bioorthogonal conjugation workflows. As an azide-functionalized linker, it is commonly used in strain-promoted or copper-catalyzed azide–alkyne cycloaddition (CuAAC) strategies to install PEG spacers onto biomolecules, surfaces, and soft materials. The reagent’s dual PEG4-t-butyl ester motif supports incorporation of hydrophilic, sterically flexible PEG architectures while enabling downstream handling of ester-protected groups under conditions compatible with bioconjugation and materials processing. Such features make it valuable for researchers developing solubility-enhanced probes, PEGylated conjugates, and functionalized biomaterial surfaces where controlled polymer spacing is important.

1. PEGylated Probe Conjugation

N-(Azido-PEG4)-N-bis(PEG4-t-butyl ester) is frequently used as a PEG installation handle for generating solubility-tuned imaging and detection reagents. By providing a terminal azide for click coupling, the reagent enables researchers to append PEG4 spacers to targeting ligands, affinity reagents, or reporter scaffolds, improving formulation behavior and reducing nonspecific interactions in assay development. The PEG4-t-butyl ester functionality supports practical conjugation workflows in which protected groups can be carried through intermediate steps, allowing downstream processing to yield the desired functional presentation on the final probe.

2. Surface Functionalization For Materials

N-(Azido-PEG4)-N-bis(PEG4-t-butyl ester) is well suited to functionalizing polymeric and biomaterial surfaces with azide-bearing PEG linkers that improve wettability and reduce surface fouling. In molecular imaging reagent development and diagnostic reagent prototyping, azide-functional PEG layers help control interfacial spacing between capture elements and the surrounding medium, which can be critical for reproducible binding performance in microenvironments. Materials scientists often incorporate this reagent into surface modification schemes to create clickable, sterically shielded platforms that can be further decorated with alkynyl ligands, reporter tags, or multivalent recognition motifs.

3. Bioconjugation Linker For Biomolecules

N-(Azido-PEG4)-N-bis(PEG4-t-butyl ester) supports bioconjugation strategies that require defined PEG spacing between a biomolecule and an appended functional group. The azide handle allows efficient coupling to alkyne-functional partners, enabling researchers to generate PEGylated conjugates for assay reagents, affinity-based enrichment tools, and labeling reagents used in chemical biology workflows. The PEG4-t-butyl ester architecture provides a practical route to incorporate flexible polymer segments that can influence solubility, steric accessibility, and conjugate stability during downstream purification and storage.

4. Clickable Crosslinker Scaffolds

N-(Azido-PEG4)-N-bis(PEG4-t-butyl ester) is used to build modular, clickable scaffold architectures where PEG spacing is required for controlled assembly. In biomaterials science and diagnostic reagent development, azide-bearing PEG linkers support stepwise construction of multicomponent systems, including PEG-mediated network formation on polymer supports and the preparation of functional surfaces or bead-based reagents for analytical workflows. The reagent’s PEG-rich structure helps maintain flexibility and reduces harsh local environments around reactive sites, which is advantageous when designing complex conjugate formats that must remain processable through routine lab handling.