DBCO-PEG12-NHS ester | CAS 2093934-94-0

DBCO-PEG12-NHS ester is a PEGylated DBCO (dibenzocyclooctyne) click-chemistry reagent that couples an NHS-activated ester to primary amines while retaining the strained-alkyne functionality needed for copper-free strain-promoted azide–alkyne cycloaddition (SPAAC). Its flexible PEG12 spacer improves solubility and spacing between the targeting/biorecognition element and the DBCO handle, making it well suited for preparing azide-reactive conjugates used in chemical biology and materials science. The NHS ester enables straightforward labeling of proteins, peptides, and other amine-containing scaffolds, which then serve as partners for downstream click conjugation to azide-bearing probes, surfaces, or biomaterials.

1. Protein Labeling And Conjugates

DBCO-PEG12-NHS ester is widely used to introduce a DBCO click handle onto proteins and peptide carriers that contain accessible primary amines, such as lysine residues or N-terminal amines. Researchers employ this reagent to generate DBCO-functional biomolecules that can subsequently be clicked to azide-functional imaging agents, affinity tags, or multivalent ligands via copper-free SPAAC. The PEG12 spacer helps reduce steric congestion and can improve conjugate homogeneity for workflows that require controlled presentation of the DBCO group on bulky protein scaffolds. This approach is common in probe preparation for mechanistic studies, assay development, and modular construction of complex bioconjugates.

2. Surface Functionalization For Biomaterials

DBCO-PEG12-NHS ester is commonly used to functionalize amine-bearing biomaterial surfaces, including polymer films, hydrogel matrices, and modified substrates that present primary amines for NHS coupling. After immobilization, the resulting DBCO-decorated surfaces act as stable click platforms for rapid attachment of azide-containing components, enabling spatially defined patterning and modular assembly of coatings. In biomaterials research, this reagent supports the creation of clickable interfaces for studying cell-material interactions, immobilizing affinity reagents, and building multilayer constructs where sequential azide–DBCO additions are advantageous. The PEG spacer contributes to improved accessibility of the reactive DBCO moiety at the material interface.

3. Fluorophore And Imaging Probe Assembly

DBCO-PEG12-NHS ester is frequently selected for preparing DBCO-tagged fluorescent labels and imaging reagents by coupling the NHS ester to amine-containing dyes, dye-protein conjugates, or other amine-functional reporter scaffolds. The DBCO handle enables subsequent conjugation to azide-bearing targeting vectors, enabling researchers to assemble probe sets with consistent chemistry and minimal cross-reactivity. PEGylation can help maintain optical performance and reduce nonspecific interactions by improving hydrophilicity and spacing around the dye conjugate. This workflow is particularly useful when modular probe construction is required, such as generating libraries of azide-reactive targeting partners that can be clicked onto a common DBCO-labeled reporter.

4. Multivalent Ligand And Targeting Platforms

DBCO-PEG12-NHS ester supports the generation of multivalent targeting constructs by enabling NHS coupling to amine-rich targeting scaffolds, including antibody fragments, receptor-binding peptides, and other ligand platforms. Once DBCO-functionalized, these ligands can be clicked to azide-bearing components such as scaffolds, linkers, or secondary targeting moieties to create higher-order architectures with controlled valency. The PEG12 linker is often leveraged to mitigate steric hindrance and to improve the accessibility of the click handle for efficient SPAAC coupling in complex conjugate mixtures. This makes the reagent a practical choice for building modular ligand systems used across chemical biology tool development and advanced conjugate engineering.

5. Diagnostic Reagent And Assay Development

DBCO-PEG12-NHS ester is used in the preparation of clickable assay reagents where amine-containing components must be equipped with a DBCO handle for later attachment to azide-functional reporters or capture elements. Typical workflows include generating DBCO-functional detection reagents, affinity reagents, or assay-building blocks that can be assembled into multicomponent formats using copper-free SPAAC. The PEG spacer can improve reagent solubility and reduce aggregation tendencies, which is valuable when assay components are combined at defined stoichiometries. This reagent is therefore commonly integrated into research-grade diagnostic reagent development and assay prototyping where modular, sequential assembly is beneficial.