Azido-PEG10-NHS ester

Azido-PEG10-NHS ester is a PEG-based heterobifunctional linker that combines an azide handle for copper-free or copper-mediated click chemistry with an NHS ester for efficient coupling to primary amines on proteins, peptides, and other amine-bearing biomolecules. The reagent’s flexible PEG spacer improves solubility and reduces steric constraints, making it a widely used building block for preparing clickable bioconjugates, imaging probes, and functionalized materials. In downstream workflows, the azide functionality enables modular attachment to alkynes (including strained alkynes) for rapid conjugation without lengthy purification steps between labeling stages.

1. Protein Surface Labeling

Azido-PEG10-NHS ester is commonly used to introduce a defined azide functionality onto proteins, antibodies, enzymes, and peptide carriers via NHS-ester coupling to accessible lysine residues or N-terminal amines. This provides a robust starting point for subsequent click reactions that install targeting ligands, fluorophores, affinity tags, or other functional moieties under conditions compatible with sensitive biomacromolecules. The PEG10 spacer helps maintain conjugate solubility and can improve labeling uniformity by reducing local crowding around the reactive sites, which is particularly valuable when preparing multi-component probes or conjugates for biochemical assays and molecular imaging development.

2. Antibody Conjugation Workflows

Azido-PEG10-NHS ester is frequently selected in antibody and scaffold conjugation workflows where a clickable handle is needed for modular assembly of imaging reagents and research-grade affinity reagents. By converting amine groups on antibody frameworks or engineered protein scaffolds into azide-bearing conjugates, researchers can later couple the antibody to alkyne-functional imaging dyes, polymeric tags, or enrichment handles using click chemistry strategies that support streamlined, stepwise construct building. The PEG spacer can also mitigate aggregation tendencies that sometimes arise when multiple functional groups are installed on large biomolecules, supporting practical handling during probe optimization and assay development.

3. Fluorophore and Imaging Probe Assembly

Azido-PEG10-NHS ester is used as a linker to prepare azide-functional imaging probes by first attaching the NHS ester to amine-containing reporter scaffolds, such as fluorescent proteins, dye–protein conjugates, or amine-derivatized nanoparticles, then using the azide for click-based installation of complementary reporter or targeting components. This two-stage design is especially useful when the final probe requires orthogonal assembly, allowing researchers to vary the alkyne partner without repeating the initial protein/dye coupling step. The PEG10 chain improves aqueous compatibility and can help preserve optical performance and colloidal stability for probe libraries used in fluorescence-based detection, microscopy labeling, and molecular imaging reagent screening.

4. Bioorthogonal Surface Functional Materials

Azido-PEG10-NHS ester is broadly applied in biomaterials science to functionalize surfaces and create azide-presenting interfaces for subsequent click immobilization of biomolecules or synthetic ligands. The NHS ester enables attachment to amine-rich substrates such as functionalized polymers, coatings, or amine-bearing hydrogel components, while the azide group provides a stable, bioorthogonal reactive site for later coupling to alkyne-functional partners. This approach supports fabrication of modular biointerfaces used for cell-labeling tool development, affinity capture materials, and research platforms requiring controlled presentation of ligands at defined spacing, where the PEG spacer helps maintain accessibility and reduces nonspecific interactions.