DOTA-PEG5-C6-DBCO

DOTA-PEG5-C6-DBCO is a DOTA-based, PEGylated cyclooctyne click reagent designed for copper-free strain-promoted azide–alkyne cycloaddition (SPAAC). The structure combines a metal-chelating DOTA macrocycle with a flexible PEG spacer and a cyclooctyne (DBCO) handle, enabling robust conjugation to azide-functional biomolecules, nanoparticles, and surfaces under mild conditions. This reagent is widely used in molecular imaging probe construction and radiolabeling workflows where stable chelation and efficient click-based attachment are critical.

1. Radiolabeled Imaging Probes

DOTA-PEG5-C6-DBCO is commonly used as a chelator-bearing click handle for assembling radiolabeled molecular imaging agents, where the DOTA motif supports coordination of diagnostic radioisotopes and the DBCO group enables rapid conjugation to azide-tagged targeting vectors. Researchers incorporate this reagent into probe design pipelines to generate well-defined DOTA-functional conjugates for subsequent radiolabeling and formulation steps, while the PEG spacer helps manage solubility and reduces steric constraints during downstream assembly. The SPAAC-compatible DBCO functionality supports streamlined workflows for producing imaging-relevant constructs with controlled attachment sites and consistent linker architecture.

2. Antibody And Ligand Conjugation

DOTA-PEG5-C6-DBCO is frequently selected for bioconjugation of antibodies, antibody fragments, peptides, and other binding ligands that have been engineered with azide groups. In these workflows, the reagent provides a modular way to install a DOTA chelator onto the ligand through SPAAC, supporting the creation of DOTA-functional immunoconjugates used as research imaging reagents and platform molecules for probe libraries. The PEG5 spacer and the C6 linker region are particularly useful for maintaining accessibility of the binding domain while positioning the chelator for efficient radiolabeling in later stages, enabling reproducible conjugate generation for molecular imaging studies.

3. Nanoparticle And Surface Functionalization

DOTA-PEG5-C6-DBCO is applied to the functionalization of inorganic and polymeric nanoparticles, as well as azide-derivatized surfaces, to introduce DOTA chelation sites for imaging and analytical reagent development. Click chemistry users leverage the DBCO handle to attach DOTA units to azide-bearing particle coatings, linkers, or material interfaces without requiring copper catalysts that can complicate sensitive formulations. This approach supports the preparation of multivalent DOTA-decorated nanomaterials where the PEG spacer can improve colloidal behavior and help present chelators outward from the particle surface, facilitating subsequent radiolabeling and characterization steps.

4. Multimodal Probe Building

DOTA-PEG5-C6-DBCO is used as a modular building block in multimodal probe construction, where DOTA chelation is combined with additional functional elements introduced via orthogonal or sequential click steps. Many chemical biology and molecular imaging groups treat this reagent as a standardized DBCO-bearing chelator to enable consistent installation of DOTA into complex probe architectures, including constructs that incorporate other reporter handles for imaging readouts or analytical tracking. The reagent’s SPAAC compatibility supports iterative assembly strategies, allowing teams to generate structured conjugates with defined chelator placement while maintaining flexible spacing that can be important for maintaining accessibility of other appended components.