DBCO-PEG4-alkyne | CAS 2741418-16-4

DBCO-PEG4-alkyne is a bifunctional click chemistry reagent that combines a strained cyclooctyne (DBCO) for copper-free strain-promoted azide–alkyne cycloaddition (SPAAC) with a terminal alkyne handle for complementary conjugation workflows. The PEG4 spacer provides aqueous compatibility and spatial separation between reactive groups, which is valuable when building multivalent bioconjugates, surface coatings, or imaging probes. This reagent is commonly used in research and materials development to introduce orthogonal reactivity, enabling sequential or modular attachment of biomolecules, polymers, and functional tags.

1. Multivalent Bioconjugation

DBCO-PEG4-alkyne is widely used to generate multivalent conjugates where a DBCO group enables copper-free coupling to azide-bearing targets, while the alkyne handle supports downstream attachment to other probes or surfaces. Researchers employ this reagent to tune valency and presentation of functional groups on proteins, peptides, and carbohydrate-bearing constructs, often improving conjugate homogeneity in labeling workflows. The PEG4 linker helps maintain solubility and reduces steric crowding during conjugation, making it suitable for assembling complex reagent panels for chemical biology studies.

2. Surface And Material Functionalization

DBCO-PEG4-alkyne is frequently applied in biomaterials and surface chemistry to functionalize polymer films, hydrogel systems, and nanoparticle platforms with azide-reactive moieties and additional alkyne-based handles for further modification. Materials teams use the reagent to create modular interfaces where DBCO-mediated attachment can be performed under mild, copper-free conditions, followed by orthogonal coupling steps using the terminal alkyne in subsequent surface immobilization strategies. The PEG4 spacer supports stable aqueous processing and helps preserve accessibility of reactive groups on otherwise crowded material surfaces.

3. Imaging Probe Assembly

DBCO-PEG4-alkyne supports the construction of molecular imaging and detection reagents by enabling staged incorporation of labels into azide-functional scaffolds and then adding secondary reporters through the terminal alkyne functionality. Molecular imaging groups and diagnostic reagent developers use this bifunctional design to streamline probe synthesis, allowing a flexible sequence of conjugation steps that can accommodate different fluorophores, affinity tags, or solid-support capture elements. The PEG4 spacer is particularly useful for maintaining probe solubility and minimizing non-specific interactions during labeling and purification.

4. Orthogonal Labeling Workflows

DBCO-PEG4-alkyne is a practical choice for orthogonal labeling strategies in chemical biology, where researchers need two distinct reactive handles to coordinate sequential modifications without cross-reactivity. The DBCO moiety is commonly used to couple to azide-containing biomolecules or biomaterial components via SPAAC, while the alkyne enables additional conjugation steps using alkyne-compatible chemistries in later stages of probe or conjugate assembly. This orthogonality supports efficient production of complex research tools such as dual-functional affinity reagents, capture-and-detection constructs, and modular reagent libraries for assay development.