DBCO-PEG2-acid | CAS 2304558-25-4

DBC0-PEG2-acid is a DBCO-functionalized, PEGylated carboxylic acid designed for copper-free strain-promoted azide–alkyne cycloaddition (SPAAC) workflows in chemical biology and materials science. The reagent combines a cyclooctyne (DBCO) click handle with a short, flexible PEG spacer terminating in a carboxylic acid, enabling robust conjugation to amine-bearing biomolecules, surfaces, and polymeric constructs via standard coupling chemistries. Its PEG-mediated spacing and aqueous compatibility make it a common choice for preparing clickable linkers for labeling, immobilization, and probe assembly in imaging and diagnostic reagent development pipelines.

1. Protein And Peptide Labeling

DBC0-PEG2-acid is widely used to install a SPAAC-reactive DBCO handle on proteins and peptides prior to downstream conjugation to azide-bearing partners such as imaging tags, affinity ligands, or multivalent detection motifs. The terminal carboxylic acid supports straightforward attachment to amine-containing biomolecules through carbodiimide coupling strategies, while the PEG spacer helps reduce steric congestion that can otherwise limit labeling efficiency. Researchers commonly employ this reagent to generate well-defined, click-ready conjugates for assay development and biomolecular characterization, including workflows where orthogonal reactivity and aqueous handling are important.

2. Surface Immobilization Chemistry

DBC0-PEG2-acid is used to functionalize solid supports, including polymer films, hydrogel materials, and microarray surfaces, where carboxyl-activated coupling enables stable attachment of the DBCO-bearing linker to the substrate. Once immobilized, the DBCO moiety provides a copper-free click interface for subsequent capture of azide-functional biomolecules, enabling modular assembly of biosensing layers and patterned biochemical surfaces. The PEG2 spacer contributes to improved accessibility of the reactive cyclooctyne at the interface, which is particularly valuable for immobilizing bulky targets such as enzymes, antibodies, or nucleic-acid probes without relying on harsh conditions.

3. Multivalent Probe And Sensor Assembly

DBC0-PEG2-acid is a practical building block for constructing multivalent chemical probes and sensor reagents that rely on SPAAC to rapidly connect DBCO-bearing scaffolds to azide-functional reporters. The carboxylic acid handle allows incorporation into linker architectures that can be coupled to carrier proteins, polymer backbones, or dendritic scaffolds, supporting the generation of click-addressable reagent libraries. In molecular imaging and diagnostic reagent development, this approach is frequently used to tune probe density and spatial presentation, improving the usability of reagents across labeling, wash-based workflows, and automated assay formats.

4. Polymer And Biomaterials Functionalization

DBC0-PEG2-acid supports the functionalization of PEG-containing polymers and biomaterials where a carboxyl terminus is needed to introduce a DBCO click site into a larger material formulation. Material scientists use the reagent to create azide-reactive polymer conjugates for hydrogel modification, coating strategies, and surface grafting, enabling subsequent attachment of bioactive or recognition elements through SPAAC. The PEG2 linker length helps maintain mobility of the DBCO group within hydrated environments, which can be advantageous for reproducible coupling of azide-bearing components during material fabrication and iterative optimization of material-based assay platforms.