Propargyl-PEG8-NHS ester | CAS 2182601-74-5

Propargyl-PEG8-NHS ester is a PEG-based NHS ester designed for strain-promoted or copper-catalyzed click chemistry workflows, enabling efficient installation of terminal alkyne handles onto amine-bearing biomolecules and surfaces. As an NHS-activated ester, it reacts under standard bioconjugation conditions with primary amines to introduce a flexible PEG spacer that improves solubility and reduces steric constraints during downstream labeling. The resulting alkyne-functional conjugates are widely used as versatile click partners for subsequent CuAAC or related coupling steps in molecular imaging, diagnostics development, and biomaterials functionalization.

1. Protein And Peptide Labeling

Propargyl-PEG8-NHS ester is commonly used to generate alkyne-functional protein and peptide conjugates for downstream click chemistry labeling. Researchers and reagent developers employ the PEG spacer to maintain target binding or recognition properties while providing a reactive terminal alkyne for attaching fluorophores, affinity tags, or imaging moieties. This approach is frequently adopted in biochemical assay development, where modular reagent exchange via click chemistry supports rapid optimization of probe density and labeling stoichiometry across different protein formats.

2. Antibody And Targeting Ligands

Propargyl-PEG8-NHS ester supports alkyne installation on antibodies and targeting ligands used in research-grade imaging and binding studies. The NHS ester chemistry enables straightforward conjugation to lysine residues, while the PEG8 chain helps mitigate aggregation and nonspecific interactions that can arise from dense labeling. After alkyne introduction, the conjugates are readily carried into CuAAC-based assembly of multivalent constructs, such as antibody–probe hybrids, antibody–nanomaterial conjugates, and modular targeting reagents used in workflow-driven assay and probe screening.

3. Surface and Nanomaterial Functionalization

Propargyl-PEG8-NHS ester is frequently applied to functionalize amine-presenting surfaces and nanomaterials with terminal alkyne groups for subsequent click-based immobilization. In materials science and chemical biology, the PEG spacer improves interfacial presentation and helps preserve surface accessibility of the alkyne for efficient coupling to patterned biomolecules, capture ligands, or reporter tags. This enables the construction of clickable coatings, biointerfaces, and reusable research platforms where orthogonal assembly steps are preferred over direct adsorption or non-specific coupling.

4. Multimodal Imaging Probe Assembly

Propargyl-PEG8-NHS ester is utilized to prepare alkyne-bearing intermediates for building multimodal imaging probes through click chemistry. By introducing a PEG-separated alkyne handle onto biomolecular scaffolds, developers can attach multiple reporters in a controlled, stepwise manner using standardized click coupling reactions. The modular nature of the alkyne handle is particularly valuable when comparing fluorophore sets, enrichment tags, or imaging reagents across different experimental designs, allowing rapid reconfiguration of probe architecture without re-optimizing the initial bioconjugation step.