DBCO-PEG5-acid | CAS 1870899-46-9

DBCO-PEG5-acid is a cyclooctyne (DBCO) functionalized polyethylene glycol carboxylic acid designed for strain-promoted azide–alkyne cycloaddition (SPAAC) in bioconjugation workflows. The PEG spacer improves aqueous solubility and helps reduce steric constraints between the reactive DBCO group and target biomolecules, surfaces, or polymer backbones. As a click-ready linker, DBCO-PEG5-acid is commonly used to introduce DBCO handles into materials and probes that are subsequently coupled to azide-bearing partners under copper-free conditions.

1. Protein And Antibody Labeling

DBCO-PEG5-acid is widely used to generate DBCO-functional protein conjugates for downstream azide-reactive labeling strategies. Researchers commonly incorporate the PEG carboxylate functionality for coupling to amine-bearing targets or for attachment to activated linkers, enabling controlled placement of the cyclooctyne handle away from the biomolecule surface. This approach supports preparation of fluorescent conjugates, affinity reagents, and multi-component labeling constructs where the PEG spacer helps maintain binding-site accessibility and reduces nonspecific crowding effects during probe assembly.

2. Surface Coatings And Biomaterials

DBCO-PEG5-acid is used to functionalize biomaterial surfaces, polymer films, and scaffold materials with SPAAC-reactive DBCO groups for subsequent immobilization of azide-tagged biomolecules. The PEG5-acid format is particularly relevant in materials engineering because it provides a convenient handle for tethering to surfaces while maintaining water compatibility and minimizing steric hindrance at the interface. Such DBCO-functional coatings are frequently employed to build modular biointerfaces, including enzyme or peptide immobilization platforms, affinity capture surfaces, and cell-interaction materials where azide-bearing ligands are introduced by click coupling.

3. PEG Linker For Nanoparticles

DBCO-PEG5-acid serves as a practical PEG-based linker for decorating nanoparticles and colloidal carriers with cyclooctyne functionality prior to azide-mediated assembly. In nanomaterials workflows, the PEG spacer helps improve colloidal stability and reduces aggregation by providing a hydrated layer around the particle, while the carboxylic acid enables attachment to polymer shells, surface-reactive chemistries, or linker systems used in nanoparticle functionalization. This makes DBCO-PEG5-acid a common reagent for constructing multivalent nanoparticle probes and modular nanoparticle conjugates that rely on azide handles for controlled surface customization.

4. Molecular Imaging Probe Building

DBCO-PEG5-acid is frequently selected for assembling imaging and detection probes through copper-free SPAAC coupling to azide-bearing reporters, targeting motifs, or signal-generating components. The PEG5 spacer supports flexible presentation of the DBCO group, which can be important when conjugating bulky ligands or when minimizing steric interference between the probe components. By enabling modular “click-to-build” workflows, DBCO-PEG5-acid helps researchers generate multi-component probe architectures for fluorescence-based assays, imaging reagent development, and analytical reagent construction where reproducible conjugation and component interchangeability are valuable.