DBCO-NHCO-PEG13-NHS ester

DBCO-NHCO-PEG13-NHS ester is a DBCO-functionalized PEGylated NHS ester designed for strain-promoted azide–alkyne cycloaddition (SPAAC) workflows and efficient bioconjugation. The reagent combines an NHS ester handle for amide coupling to primary amines with a terminal DBCO group for rapid, catalyst-free click attachment to azide-bearing partners. Its extended PEG13 spacer helps improve conjugation accessibility and reduces steric constraints, making it a widely used intermediate for building azide-reactive probes, surface coatings, and multi-component labeling strategies in chemical biology and biomaterials research.

1. Amine-to-Azide Probe Labeling

DBCO-NHCO-PEG13-NHS ester is commonly used to pre-functionalize proteins, peptides, antibodies, and other amine-containing biomolecules with a DBCO moiety via NHS ester coupling. Researchers then use the resulting DBCO-labeled biomolecule to click onto azide-functional reporters such as fluorophores, affinity tags, or imaging handles, enabling modular probe assembly with minimal cross-reactivity. The PEG13 spacer supports consistent labeling and helps maintain binding or recognition properties by improving accessibility of the click-reactive DBCO group on the conjugate.

2. Surface Coating And Materials Functionalization

DBCO-NHCO-PEG13-NHS ester is frequently applied to functionalize polymer surfaces, hydrogel matrices, and biomaterial scaffolds that present accessible primary amines, including amine-terminated coatings and activated biomaterial formulations. After immobilization, the DBCO-functional layer serves as a stable platform for subsequent SPAAC coupling to azide-bearing components, such as fluorescent dyes, bioactive ligands, or detection reagents. This two-step approach is widely adopted in materials science because it separates surface functionalization from final labeling, allowing flexible tuning of surface chemistry for imaging, sensing, and assay development.

3. Multicomponent Conjugate Construction

DBCO-NHCO-PEG13-NHS ester supports sequential assembly of complex conjugates where an NHS-activated step installs the DBCO handle, followed by SPAAC attachment to an azide-containing payload. This workflow is particularly useful for creating multi-functional research tools that combine targeting, tracking, and immobilization features in one construct, such as DBCO-bearing carrier molecules that are later clicked to azide-tagged nanoparticles, polymers, or biomolecular domains. The PEG13 linker provides a practical balance between reactive-group spacing and conjugate stability, which can be advantageous when building larger or sterically demanding architectures.

4. Molecular Imaging Reagent Development

DBCO-NHCO-PEG13-NHS ester is used in the development of imaging and labeling reagents where controlled attachment of DBCO to an amine-bearing targeting scaffold is required before introducing the imaging moiety. By coupling the NHS ester to the targeting component first, researchers can then click the DBCO-functional conjugate to azide-containing imaging tags under mild, catalyst-free conditions. The reagent’s PEG13 spacer is often leveraged to improve labeling consistency and reduce steric effects around the click site, supporting robust generation of well-defined imaging probes for assay workflows and analytical studies.