BCN-PEG3-amine (exo) | CAS 1841134-72-2

BCN-PEG3-amine (exo) is a bicyclononyne (BCN) click chemistry reagent bearing a short PEG3 linker and a terminal primary amine, designed for strain-promoted azide–alkyne cycloaddition (SPAAC) without copper. Its exo-oriented BCN functionality enables efficient conjugation to azide-bearing biomolecules, surfaces, and polymer systems under mild conditions, while the PEG3 spacer supports solubility and reduces steric congestion around the reactive handle. The terminal amine makes the resulting conjugates readily addressable for downstream coupling, labeling, and surface immobilization workflows commonly used in chemical biology and materials research.

1. Azide Biomolecule Conjugation

BCN-PEG3-amine (exo) is widely used to functionalize azide-containing proteins, peptides, glycans, and nucleic-acid probes through copper-free SPAAC, enabling rapid assembly of labeled biomolecular conjugates for assay development and mechanistic studies. The PEG3 spacer helps maintain aqueous compatibility and promotes uniform labeling when working with sensitive biomolecules or multivalent azide constructs. After conjugation, the retained primary amine on BCN-PEG3-amine (exo) provides a convenient functional handle for subsequent bioconjugation steps such as secondary coupling to activated esters, isothiocyanates, or aldehyde-derived chemistries used in probe generation.

2. Surface Coating And Immobilization

BCN-PEG3-amine (exo) supports the creation of functional interfaces by reacting with azide-functionalized surfaces, beads, and polymer coatings to install BCN-derived linkers that present a primary amine for further attachment chemistry. This application is common in biomaterials science and analytical chemistry, where researchers build azide-presenting capture layers and then use BCN-PEG3-amine (exo) to tune surface charge, spacing, and accessibility of immobilized ligands. The PEG3 segment contributes to reduced nonspecific interactions and improved presentation of amine-bearing conjugates on microarrays, chromatography media, and functionalized membranes.

3. Molecular Imaging Probe Building

BCN-PEG3-amine (exo) is used as a modular BCN-based reagent for constructing azide-reactive imaging and detection probes, including fluorescent and luminescent labeling platforms that require orthogonal, copper-free conjugation. Researchers often introduce azide tags into targeting vectors or scaffold molecules and then use BCN-PEG3-amine (exo) to append a PEG3-extended amine handle that can be leveraged for dye attachment, affinity tag incorporation, or linker exchange. The ability to perform SPAAC under mild conditions makes BCN-PEG3-amine (exo) a practical choice for assembling probe libraries where consistent linker length and reactive amine functionality are important for downstream labeling uniformity.

4. Polymer And Hydrogel Functionalization

BCN-PEG3-amine (exo) is commonly applied to functionalize azide-bearing polymers and hydrogel networks, allowing incorporation of amine-terminated PEG3 spacers into otherwise inert materials. In biomaterials workflows, azide-functional monomers or crosslinkers are introduced during polymer synthesis, and BCN-PEG3-amine (exo) is then used to post-functionalize the material with BCN-derived moieties while maintaining compatibility with aqueous processing. The resulting amine functionality enables secondary modifications such as attachment of bioactive peptides, conjugation of affinity ligands, or coupling to reactive crosslinkers used to tune material properties for chemical biology tool development and surface-reactive material systems.