Azido-PEG5-CH2CO2-PFP | CAS 2144777-92-2

Azido-PEG5-CH2CO2-PFP is a PEG-based azide click chemistry reagent combining a terminal azide for bioorthogonal conjugation with a pentafluorophenyl (PFP) ester handle for efficient coupling to primary amines. This bifunctional design supports two-step workflows commonly used in chemical biology, where the PFP ester enables attachment to amine-containing biomolecules or surfaces, followed by azide-based labeling in downstream copper-free or copper-catalyzed click reactions. The flexible PEG5 spacer improves solubility and reduces steric effects, making the reagent well suited for preparing functionalized probes, imaging reagents, and biomaterial surfaces that require controlled conjugation density.

1. Amine-Targeted Probe Labeling

Azido-PEG5-CH2CO2-PFP is widely used to install an azide-functional linker onto amine-bearing targets such as peptides, proteins, antibodies, and polymeric carriers using the PFP ester reactivity toward primary amines. The resulting azide-modified biomolecule can then be carried forward into labeling workflows, including attachment of fluorophores, affinity tags, or other reporter moieties via subsequent click chemistry. In research settings, this approach is commonly chosen to preserve biomolecular activity while enabling modular, orthogonal downstream conjugation, particularly when a PEG spacer is beneficial for minimizing steric hindrance.

2. Surface Functionalization For Biomaterials

Azido-PEG5-CH2CO2-PFP is applicable to the preparation of azide-functional biomaterial surfaces and coatings through coupling to amine-containing substrates, such as amine-terminated polymers, hydrogel components, or functionalized nanoparticles. The PEG5 tether helps maintain accessibility of the azide group after immobilization, supporting efficient secondary click attachment of ligands, imaging handles, or cell-interaction motifs. This type of reagent is frequently selected in biomaterials and materials chemistry workflows where robust surface chemistry is required to generate stable, addressable interfaces for multicomponent assembly.

3. Modular Conjugation In Imaging Workflows

Azido-PEG5-CH2CO2-PFP is used as a key intermediate for building modular molecular imaging and detection reagents, where an azide handle provides a convenient point for later conjugation to dyes, affinity probes, or other imaging reporters. The PFP ester enables rapid incorporation of the PEG-azide motif into amine-rich biomolecular scaffolds, after which click-compatible partners can be attached under conditions tailored to the reporter chemistry. This strategy is particularly valuable when researchers need to standardize linker installation across multiple targets while keeping the final imaging functionality interchangeable.

4. Linker For Multistep Bioconjugation

Azido-PEG5-CH2CO2-PFP supports multistep bioconjugation strategies that separate the initial installation of the PEG-azide motif from the final assembly of the desired probe format. By first using the PFP ester to couple to primary amines, the reagent provides a stable intermediate that can be stored and then reacted with complementary click reagents to generate final constructs such as tagged affinity reagents, composite labeling reagents, or multi-component research tools. The PEG5 spacing and the orthogonality of the azide handle make it a practical choice for workflows that require controlled conjugation architecture and compatibility with downstream labeling chemistries.