5-endo-BCN-pentanoic acid | CAS 2364591-80-8

5-endo-BCN-pentanoic acid is a BCN (bicyclononyne) cycloalkyne click chemistry reagent designed for strain-promoted, bioorthogonal ligation with azides. As a carboxylic acid functionalized BCN, it combines the high-reactivity cyclooctyne-like handle used in BCN chemistry with a convenient acid for conjugation, surface attachment, and downstream coupling. This reagent is commonly selected for building azide-containing probes, labeling platforms, and functional biomaterials where robust click conjugation and handle-bearing geometry are advantageous.

1. Bioconjugation Labeling

5-endo-BCN-pentanoic acid is widely used to generate azide-reactive labeling reagents for protein, peptide, and polymer conjugation workflows in chemical biology and glycobiology. The pentanoic acid handle enables convenient coupling to amine- or activated-ester bearing targets, allowing researchers to position the BCN moiety for efficient subsequent ligation to azide tags. In practice, this supports modular assembly of fluorescent or affinity probes, enabling consistent reagent-to-target attachment strategies for imaging and assay development.

2. Surface Immobilization Chemistry

5-endo-BCN-pentanoic acid is suitable for creating azide-functional surfaces and coatings used in biosensing, affinity capture, and materials research. The carboxylic acid functionality supports attachment to polymer films, hydrogel matrices, or activated solid supports, while the BCN group provides a click handle for later reaction with azide-bearing biomolecules or nanoparticles. This two-step design is frequently adopted to decouple material fabrication from labeling, improving reproducibility when building reusable capture platforms and spatially patterned conjugates.

3. Molecular Imaging Probe Construction

5-endo-BCN-pentanoic acid is employed in the construction of molecular imaging and detection probes that rely on azide-tagged targeting elements. Researchers use it to incorporate a BCN click handle into probe scaffolds so that azide-containing dyes, reporters, or targeting ligands can be assembled under mild, bioorthogonal conditions. The 5-endo BCN architecture and flexible pentanoic acid spacer help tune probe presentation, which is often important for balancing reactivity and accessibility in complex labeling schemes.

4. Diagnostic Reagent Development

5-endo-BCN-pentanoic acid supports the development of research-grade diagnostic reagents and assay components that use azide-modified detection elements. By providing a stable BCN conjugation handle with a carboxylic acid for scaffold attachment, it enables streamlined construction of multicomponent assay reagents such as labeled affinity reagents, reporter conjugates, and modular assay building blocks. This approach is commonly favored in diagnostic reagent R&D because it supports flexible swapping of azide-tagged components without changing the core conjugation platform.