Azido-PEG12-propionic acid | CAS 1167575-20-3

Azido-PEG12-propionic acid is a PEG-based azide building block designed for copper-free and copper-enabled click chemistry workflows, where the azide handle enables rapid conjugation to complementary alkyne partners. The long, flexible PEG spacer improves aqueous solubility and reduces steric constraints, making it well suited for preparing bioconjugates, labeling reagents, and functionalized materials. Its propionic acid functionality further supports downstream coupling strategies for attaching the PEG-azide motif to surfaces, linkers, or carrier scaffolds used in chemical biology and molecular imaging tool development.

1. Surface Functionalization

Azido-PEG12-propionic acid is commonly used to introduce an azide-functional PEG spacer onto polymeric or inorganic surfaces, enabling subsequent click attachment of fluorescent tags, affinity ligands, or imaging moieties via alkyne-bearing partners. The PEG chain helps maintain accessibility of the azide group at the interface and improves wetting in aqueous processing steps, which is particularly valuable for coating and patterning workflows in materials chemistry and assay development. Researchers also use this reagent as a standardized PEG-azide linker to tune interfacial spacing and reduce nonspecific interactions in surface-based binding platforms.

2. Bioconjugate Linker Synthesis

Azido-PEG12-propionic acid serves as a versatile intermediate for generating PEGylated bioconjugation reagents where an azide handle is required for modular assembly. The combination of a hydrophilic PEG spacer and a terminal carboxylic acid supports incorporation into larger linker architectures used to connect biomolecules, peptides, or macromolecular carriers to imaging or detection components through click chemistry. In chemical biology laboratories, this reagent is frequently selected to balance conjugation efficiency with improved solubility and reduced steric hindrance, supporting robust labeling workflows for probe preparation.

3. Fluorescent Probe Assembly

Azido-PEG12-propionic acid is widely applied in the construction of fluorescent labeling tools that require a PEG-extended azide for efficient coupling to alkyne-functional dyes or dye-conjugate scaffolds. The PEG12 spacer helps preserve dye accessibility after conjugation, which can be important for maintaining strong signal generation in probe formats used across microscopy, flow-based assays, and platform screening. By providing a consistent azide-bearing linker with a carboxylic acid handle, it supports flexible design of probe architectures used for tracking biomolecular interactions and for building multi-component optical readouts.

4. Molecular Imaging Reagent Development

Azido-PEG12-propionic acid is used as a click-ready PEG linker in the preparation of molecular imaging reagents, particularly where modular attachment of targeting or reporting groups is required. The azide group enables straightforward conjugation to alkyne-functional imaging reporters, while the extended PEG spacer supports solubility and reduces aggregation tendencies in complex labeling mixtures. Imaging-oriented research groups often select PEG-azide linkers like this to control spatial presentation of the reporter and to facilitate rapid interchange of alkyne-bearing components during probe optimization and assay prototyping.