Azido-PEG1-PFP ester | CAS 1807505-32-3

Azido-PEG1-PFP ester is a heterobifunctional click chemistry reagent combining an azide handle with a short polyethylene glycol spacer and a pentafluorophenyl (PFP) ester for acyl transfer. As a key component for strain-promoted or copper-free click workflows (via azide reactivity), it is commonly used to introduce bioorthogonal labeling sites onto proteins, peptides, and other amine-bearing biomolecules. The PFP ester motif enables efficient coupling under conditions used for bioconjugation, while the PEG1 spacer improves solubility and reduces steric constraints during downstream conjugation and imaging applications.

1. Protein Labeling Workflows

Azido-PEG1-PFP ester is widely used to functionalize proteins and peptides with a defined azide tag for subsequent click-based attachment of fluorophores, affinity handles, or solid-support linkers. Researchers in chemical biology and molecular imaging often choose this reagent when they need a compact, PEG-assisted conjugation strategy that maintains accessibility of the azide for later bioorthogonal reactions. The PFP ester reactivity toward nucleophiles supports straightforward incorporation of the azide-bearing acyl group onto target biomolecules, enabling modular probe assembly for microscopy, flow-based assays, and analytical characterization of labeled biomaterials.

2. Surface And Bead Conjugation

Azido-PEG1-PFP ester is commonly applied in immobilization workflows where azide-functional surfaces, membranes, or affinity beads are required for high-throughput capture and labeling. By installing azide groups through PFP-ester coupling chemistry, laboratories can create reusable platforms for subsequent click conjugation of detection reagents, enrichment ligands, or imaging reporters. The short PEG spacer helps maintain surface accessibility of the azide moiety, which is particularly valuable for heterogeneous formats such as microarrays, magnetic beads, and polymer-coated substrates used in diagnostic reagent development and research screening.

3. Targeted Probe Assembly

Azido-PEG1-PFP ester supports modular construction of azide-bearing probes used in molecular imaging and chemical biology tool development, where the azide serves as a reliable bioorthogonal attachment point. Probe designers frequently incorporate this reagent into labeling pipelines to generate intermediate conjugates that can be rapidly coupled to complementary click partners, including fluorescent dyes, quencher-bearing constructs, or affinity-tagged reporters. The reagent’s PEG-assisted architecture is advantageous when maintaining solubility and minimizing nonspecific interactions during probe preparation and subsequent downstream conjugation steps.

4. Materials Functionalization For Imaging

Azido-PEG1-PFP ester is used to introduce azide functionality into biomaterials and imaging-relevant polymers for later click-based integration of dyes, targeting motifs, or reporter groups. Materials scientists often rely on PFP ester chemistry to graft azide-bearing linkers onto amine-containing surfaces or coatings, enabling patterned or modular functionalization without requiring extensive redesign of the material platform. The resulting azide density and accessibility can be tuned by the conjugation workflow, allowing researchers to build imaging-capable materials such as labeled hydrogels, coated particles, and scaffolded surfaces for advanced microscopy and analytical studies.