Azido-PEG8-CH2COOH | CAS 1343472-07-0

Azido-PEG8-CH2COOH is a PEG-based azide functionalized carboxylic acid designed for copper-free and copper-mediated click chemistry workflows, most commonly used in strain-promoted or CuAAC-compatible bioconjugation strategies. The reagent combines a terminal azide handle with a flexible PEG8 spacer and a carboxyl group, enabling robust conjugation to biomolecules, polymers, and surfaces while maintaining solubility and reduced nonspecific interactions. Its amphiphilic, water-compatible architecture makes it a practical building block for constructing azide-tagged probes, materials, and imaging reagents that require a stable, orthogonal reactive handle.

1. Biomolecule PEGylation

Azido-PEG8-CH2COOH is widely used as an azide-PEG linker to introduce a polyethylene glycol spacer and a terminal carboxyl group into proteins, peptides, and other biomolecular scaffolds prior to downstream click conjugation. Researchers often use the carboxyl functionality for coupling strategies that pre-position the PEG chain, while the azide provides a reliable reactive site for attaching fluorescent dyes, affinity tags, or other imaging/assay reporters through click chemistry. The PEG8 segment helps improve aqueous handling and can reduce aggregation during labeling workflows, which is particularly valuable when preparing multi-component conjugates for biochemical assays and molecular imaging tool development.

2. Surface And Material Functionalization

Azido-PEG8-CH2COOH is used to functionalize polymeric materials, nanoparticles, and solid supports with an azide handle for subsequent attachment of ligands, capture molecules, or reporter groups. The carboxylic acid enables anchoring or surface coupling to materials that support carboxyl-activated chemistries, while the PEG8 spacer provides steric spacing that can improve accessibility of the azide for later click reactions. This approach is common in materials chemistry and chemical biology for building modular surfaces, creating azide-functional coatings, and assembling multivalent constructs where controlled presentation of reactive groups is essential.

3. Fluorescent Probe And Imaging Tags

Azido-PEG8-CH2COOH serves as a convenient azide-bearing PEG linker for preparing fluorescent probes and imaging tags that require a flexible spacer between the targeting or recognition element and the reporter. In typical workflows, the reagent is incorporated into probe scaffolds so that the azide can be clicked to dye-derivatized partners, allowing researchers to tune labeling density and spacing without compromising solubility. The PEG8 chain is especially useful when constructing conjugates for microscopy, flow-based assays, or other optical readouts, where minimizing nonspecific interactions and maintaining colloidal stability improve reproducibility during probe preparation.

4. Diagnostic Reagent Building Blocks

Azido-PEG8-CH2COOH is commonly selected as a modular component for diagnostic reagent development and assay tooling that relies on click-compatible conjugation to generate defined, azide-reactive intermediates. The reagent’s azide handle supports straightforward attachment of assay reporters, capture moieties, or signal-generating components in a controlled manner, while the PEG8 spacer and carboxyl group support practical intermediate handling during reagent assembly. Teams developing multiplexed assay reagents, labeling kits, and standardized conjugation workflows often favor PEG-based linkers to improve aqueous stability and to help achieve consistent conjugate architectures across batches.