BCN-exo-PEG8-NHS | CAS 1608140-48-2

BCN-exo-PEG8-NHS is a BCN (bicyclononyne) functionalized, PEG8-linked NHS ester designed for strain-promoted click chemistry and downstream bioconjugation workflows. The reagent combines an NHS-activated ester for efficient coupling to primary amines with a cyclooctyne-type click handle that reacts with tetrazines, enabling modular labeling and surface modification. Its PEG spacer supports improved solubility and reduced steric effects, making it well suited for creating stable, site-accessible conjugates for chemical biology and materials research.

1. Amine-Targeted Surface Labeling

BCN-exo-PEG8-NHS is widely used to functionalize proteins, peptides, and polymer surfaces through NHS-ester coupling to lysine residues or N-termini, generating amine-reactive conjugates bearing an exo-BCN click handle. Researchers incorporate the resulting BCN-modified biomolecules into labeling workflows where a subsequent tetrazine reagent provides orthogonal, rapid conjugation under mild conditions. This approach is commonly applied to prepare clickable coatings on bioconjugation-compatible substrates, including functionalized nanoparticles and assay-ready surfaces, where controlled introduction of a cyclooctyne handle improves downstream imaging or enrichment strategies.

2. Tetrazine-Triggered Probe Conjugation

BCN-exo-PEG8-NHS serves as a practical entry point for building two-step labeling pipelines that separate amine coupling from the final click event. After installing the BCN handle onto a target (for example, a carrier protein, targeting ligand, or scaffold), the BCN conjugate can be reacted with tetrazine-containing probes to generate fluorescent, affinity, or reporter-tagged constructs with high chemoselectivity. The PEG8 linker helps maintain probe accessibility and reduces non-specific interactions, supporting consistent performance in multi-component labeling experiments used in chemical biology, molecular imaging tool development, and diagnostic reagent prototyping.

3. Biomaterials Functionalization Workflows

BCN-exo-PEG8-NHS is frequently employed to introduce click-ready BCN functionality into biomaterial platforms that require subsequent modular assembly. By coupling the NHS ester to amine-bearing hydrogels, coatings, or polymeric scaffolds, laboratories can create surfaces and matrices that later undergo tetrazine-mediated conjugation with imaging agents, affinity ligands, or macromolecular components. The exo-BCN presentation and PEG spacer are particularly useful when maintaining reactivity at the material interface is critical, such as in constructing clickable tissue-mimetic environments, functionalized membranes, or layered composite materials for research-grade assay development.

4. Molecular Imaging Reagent Building

BCN-exo-PEG8-NHS is used as a building block for generating BCN-bearing imaging reagents and research probes that rely on tetrazine click coupling for final assembly. Teams developing fluorescent or other reporter-tagged constructs often prefer this two-stage design: first, install BCN onto an amine-containing targeting or carrier component using the NHS ester; then, perform the final click step with a tetrazine-functional reporter to achieve efficient, selective labeling. The PEG8 spacer supports probe solubility and helps preserve signal performance by improving accessibility of the click handle, which is valuable in workflows that demand reproducible conjugate preparation for microscopy, flow-based readouts, or imaging reagent screening.