N-Boc-N-bis(PEG4-azide) | CAS 2055041-25-1

N-Boc-N-bis(PEG4-azide) is a protected, PEG-based bis-azide click chemistry reagent designed to introduce two azide handles into biomolecule and polymer conjugation workflows. As a difunctional azide building block, it is commonly used in strain-promoted or copper-catalyzed azide–alkyne cycloaddition strategies to enable multivalent labeling, surface functionalization, and modular assembly of imaging and materials platforms. The Boc-protected nitrogen and PEG4 spacing provide practical stability and flexible distance control, which is especially valuable when constructing well-defined conjugates for research-grade probe development and biomaterials engineering.

1. Multivalent Probe Labeling

N-Boc-N-bis(PEG4-azide) is used to generate multivalent azide-functional probes for fluorescence, affinity, and imaging reagent development, where two reactive handles improve conjugation density and signal robustness in labeling schemes. Researchers commonly incorporate this reagent into workflows that require controlled spacing between conjugation sites, leveraging the PEG4 segments to reduce steric crowding and maintain accessibility of downstream click partners. The Boc-protected motif supports handling during reagent preparation and conjugation assembly, making it convenient for building libraries of azide-bearing intermediates used in probe optimization studies.

2. Biomolecule Conjugation Platforms

N-Boc-N-bis(PEG4-azide) serves as a practical azide source for preparing click-ready biomolecule conjugates, including azide-functional linkers for proteins, peptides, and nucleic-acid-associated constructs used in chemical biology. In these applications, the reagent’s bis-azide functionality enables crosslinking or dual-site attachment to orthogonal alkyne-bearing partners, supporting the construction of defined architectures such as multivalent binding reagents and modular assay components. PEG4 spacing is frequently selected to promote solubility and to help preserve biomolecular behavior during conjugation and subsequent experimental handling.

3. Surface and Hydrogel Functionalization

N-Boc-N-bis(PEG4-azide) is widely applied in materials science to introduce azide functionality onto surfaces and soft materials, including polymer films and hydrogel networks, where click chemistry provides efficient post-functionalization. The ability to present two azide groups per reagent supports higher grafting density and network connectivity when paired with complementary alkyne-functional surfaces or crosslinkers. Such azide-functional materials are commonly used as platforms for immobilizing affinity ligands, assembling responsive coatings, and creating spatially defined attachment points for downstream molecular imaging or analytical reagent development.

4. Modular Imaging Reagent Assembly

N-Boc-N-bis(PEG4-azide) is used as a modular building block for assembling imaging reagents that require two-point conjugation to alkyne-bearing fluorophores, nanoparticles, or scaffold molecules. The bis-azide design supports multivalent coupling strategies that can improve construct uniformity and enable systematic variation of labeling geometry across probe panels. PEG4 linkers help maintain colloidal stability and accessibility of the clickable sites during reagent preparation, which is particularly useful in workflows that prioritize reproducible probe construction for microscopy, spectroscopy, and analytical detection tool development.