Azido-PEG8-C1-NHS ester | CAS 2182601-81-4

Azido-PEG8-C1-NHS ester is a PEG-based azide-functionalized NHS ester designed for click chemistry workflows and covalent bioconjugation. It combines an N-hydroxysuccinimide ester for efficient reaction with primary amines on biomolecules or surfaces with a terminal azide handle for subsequent strain-promoted or copper-catalyzed azide–alkyne cycloaddition. The PEG8 spacer provides improved solubility and spacing control, making the reagent widely used to prepare azide-bearing conjugates for downstream labeling, imaging, and material functionalization.

1. Amine-Targeted Bioconjugation

Azido-PEG8-C1-NHS ester is commonly used to functionalize antibodies, antibody fragments, proteins, peptides, and other amine-containing biomolecules with a pendant azide for later click attachment of dyes, affinity tags, or imaging moieties. The NHS ester chemistry enables straightforward coupling under standard bioconjugation conditions, while the PEG8 tether helps reduce steric constraints and promotes more uniform presentation of the azide handle. Researchers frequently employ this reagent to generate azide-labeled reagents that can be standardized across experiments, including multicolor labeling panels and modular probe construction for chemical biology toolkits.

2. Modular Probe And Labeling

Azido-PEG8-C1-NHS ester supports modular assembly of fluorescent probes, affinity probes, and detection reagents by converting amine-bearing scaffolds into azide-functional intermediates. Once conjugated, the azide group serves as a versatile click handle for attaching alkynyl reporters such as fluorophores, quenchers, or enrichment tags, enabling rapid interchange of labels without re-optimizing the initial bioconjugation step. This approach is particularly valuable in molecular imaging and assay development workflows where researchers need consistent conjugation chemistry and flexible downstream coupling to different reporter formats.

3. Surface and Material Functionalization

Azido-PEG8-C1-NHS ester is used to introduce azide functionality onto amine-presenting surfaces and biomaterials, including functionalized polymers, nanoparticles, and protein-coated substrates. The NHS ester allows covalent immobilization onto materials bearing accessible primary amines, while the PEG8 spacer improves colloidal stability and helps maintain reactivity of the azide for subsequent click-based grafting. Downstream, azide-functional materials can be coupled to complementary alkyne-bearing ligands, crosslinkers, or imaging components to create spatially controlled interfaces for research-grade diagnostics and materials science applications.

4. Multivalent Linker Construction

Azido-PEG8-C1-NHS ester is frequently selected to build multivalent or branched conjugates where controlled linker length and click-ready azide density are important. By coupling the NHS ester to an amine-rich carrier (such as a protein scaffold or polymer backbone), the resulting azide-bearing intermediate can be used to attach multiple alkyne partners, facilitating the design of higher-order labeling constructs and organized probe architectures. This use case is common in chemical biology and molecular imaging reagent development, where tunable spacing and modularity help researchers generate reproducible conjugate formats for platform-style studies.