endo-BCN-PEG3-mal | CAS 2141976-33-0

endo-BCN-PEG3-mal is a PEG3-linked, maleimide-functionalized bicyclononyne (BCN) click chemistry reagent designed for strain-promoted cycloaddition with tetrazines in bioorthogonal labeling workflows. The endo-BCN scaffold provides the reactive cyclooctyne-like handle, while the PEG3 spacer improves aqueous handling and reduces steric constraints during conjugation to biomolecules and surfaces. The maleimide group enables straightforward installation onto thiol-bearing targets, making endo-BCN-PEG3-mal a practical bridge reagent for preparing tetrazine-reactive probes for molecular imaging, diagnostics research, and biomaterials functionalization.

1. Tetrazine Probe Conjugation

endo-BCN-PEG3-mal is commonly used to generate BCN-bearing labeling reagents that can subsequently react with tetrazine partners for rapid, selective bioorthogonal signal generation. Researchers employ this reagent to functionalize antibodies, affibodies, peptides, or other thiol-containing binding scaffolds with a BCN handle, enabling modular probe assembly for fluorescence, luminescence, or mass-tag readouts. The PEG3 spacer helps maintain accessibility of the BCN moiety, supporting consistent labeling performance across different biomolecule sizes and conjugation densities.

2. Surface and Material Functionalization

endo-BCN-PEG3-mal is well suited for introducing BCN functionality onto polymeric and inorganic surfaces through maleimide-thiol coupling strategies. Biomaterials scientists use it to decorate hydrogels, nanoparticles, and coating layers with tetrazine-reactive groups, facilitating downstream attachment of imaging agents, affinity ligands, or reporter molecules under mild conditions. The maleimide provides a convenient handle for immobilization onto thiolated linkers or surface-modified materials, while the PEG3 chain supports improved dispersion and reduced non-specific interactions at interfaces.

3. Targeted Imaging Reagent Building

endo-BCN-PEG3-mal is frequently incorporated into workflows that build tetrazine-based imaging reagents by first installing BCN onto targeting or localization components. Molecular imaging groups use the maleimide functionality to conjugate BCN to thiolated targeting vectors, such as small-molecule linkers, protein domains, or engineered binding proteins, before pairing with tetrazine-tagged dyes or reporters. This two-step modular approach supports rapid iteration of probe formats for microscopy, flow-based assays, and imaging platform development, where consistent BCN presentation is critical.

4. Diagnostic Research Labeling Tools

endo-BCN-PEG3-mal supports the development of research-grade diagnostic labeling tools that rely on bioorthogonal tetrazine chemistry for clean signal generation. Diagnostic reagent developers use the maleimide group to attach BCN to capture reagents, assay components, or affinity matrices that contain accessible thiols, creating standardized BCN-functional building blocks. Subsequent reaction with tetrazine-containing reporters enables flexible swapping of detection modalities, including fluorescent and chemiluminescent tags, while the PEG3 spacer helps preserve reactivity and minimizes steric hindrance in complex assay environments.