bis-PEG2-endo-BCN | CAS 1476737-97-9

bis-PEG2-endo-BCN is a bis-functional, PEGylated bicyclononyne (BCN) click chemistry reagent designed for strain-promoted azide–alkyne cycloaddition (SPAAC) with azides under copper-free conditions. The endo-BCN architecture provides efficient reactivity toward azide partners, while the PEG2 spacer and bis-functional design support multivalent labeling and improved solubility in aqueous workflows. bis-PEG2-endo-BCN is commonly selected for building modular biomaterials, preparing functional imaging probes, and generating well-defined conjugates in chemical biology and diagnostics research.

1. Multivalent Biomolecule Labeling

bis-PEG2-endo-BCN is widely used to introduce two BCN reactive handles into azide-bearing biomolecules, enabling multivalent conjugation strategies that improve labeling density and conjugate homogeneity for downstream assays. Researchers commonly pair bis-PEG2-endo-BCN with azide-functional proteins, peptides, oligonucleotides, or cell-surface targeting constructs to generate defined dual-site adducts for mechanistic studies, binding assays, and platform development. The PEG2 spacing helps maintain aqueous compatibility and reduces nonspecific aggregation during conjugation and purification steps, making the reagent a practical choice for workflows that require consistent, reproducible functionalization.

2. Hydrogel And Surface Functionalization

bis-PEG2-endo-BCN supports copper-free click immobilization of BCN-bearing PEG constructs onto azide-functional hydrogels and polymer surfaces, facilitating rapid fabrication of functional biomaterials. Biomaterials groups use this reagent to pattern or crosslink azide-containing matrices, incorporate bioorthogonal ligands, and tune surface chemistry for cell-interaction studies and materials characterization. The bis-functional nature is particularly useful when dual attachment points are desired to enhance network stability or to control ligand presentation on scaffolds and coatings used in laboratory-scale device prototyping and materials screening.

3. Molecular Imaging Probe Construction

bis-PEG2-endo-BCN is commonly incorporated into molecular imaging and detection reagent development as a modular BCN building block for attaching azide-tagged fluorophores, affinity moieties, or reporter groups. Chemical biology teams rely on the PEGylated bis-BCN format to improve solubility and to support controlled multivalent probe assembly, which can be advantageous when designing higher-affinity labeling reagents or signal-amplified constructs for microscopy and analytical workflows. The copper-free SPAAC compatibility also aligns with sensitive labeling environments where minimizing metal exposure is important for preserving probe integrity during conjugation.

4. Diagnostic Reagent And Assay Platforms

bis-PEG2-endo-BCN is used in the preparation of research diagnostic reagents and assay components that require bioorthogonal coupling to azide-functional capture elements, reporters, or assay surfaces. Suppliers and academic groups often select this reagent to assemble dual-functional conjugates, such as linking azide-bearing detection labels to azide-presenting assay formats, including bead-based assays and microarray-style reagent libraries. The bis-functional PEG2 scaffold helps streamline reagent handling in aqueous buffers and supports scalable conjugation workflows used for method development, reagent optimization, and assay prototyping.