Azide-PEG12-Tos | CAS 1821464-56-5

Azide-PEG12-Tos is a PEGylated azide building block bearing a tosylate leaving group, designed for click chemistry workflows and subsequent functional conjugation. As an azide-containing reagent, it is commonly used as a partner in copper-free or copper-catalyzed azide–alkyne cycloaddition to install bioorthogonal handles on biomolecules, surfaces, and materials. The extended PEG12 spacer improves solubility and reduces steric interference, while the tosylate functionality enables additional electrophile-driven coupling routes in downstream labeling and material modification strategies. This combination makes Azide-PEG12-Tos a practical reagent for constructing modular, water-compatible conjugates used in chemical biology, imaging probe development, and biomaterials functionalization.

1. Bioorthogonal Surface Labeling

Azide-PEG12-Tos is widely used to introduce azide functionality onto polymeric or inorganic surfaces where subsequent click conjugation enables attachment of targeting ligands, fluorophores, or affinity tags. The PEG12 spacer helps maintain accessibility of the azide group after immobilization, which is important for consistent labeling of coatings, membranes, and microfabricated platforms. Researchers in chemical biology and materials science rely on this reagent to generate modular surface chemistries that can be rapidly diversified using complementary alkyne-bearing partners.

2. Protein and Peptide Conjugation

Azide-PEG12-Tos supports azide installation on proteins and peptides used in labeling workflows, enabling later conjugation to imaging reporters, affinity handles, or polymeric constructs through azide–alkyne click chemistry. The PEG12 chain improves aqueous handling and can mitigate steric effects that otherwise reduce conjugation efficiency or accessibility of reactive groups. In research settings focused on bioconjugation, Azide-PEG12-Tos is commonly selected when a long, flexible linker is beneficial for preserving biomolecular recognition and for building multicomponent labeling strategies.

3. Fluorophore and Imaging Probe Assembly

Azide-PEG12-Tos is frequently incorporated into the synthesis of fluorescent and luminescent imaging probes where an azide handle is required for modular assembly with alkyne-functional dyes or reporters. The PEG12 spacer can enhance probe solubility and reduce non-specific interactions by providing a hydrophilic, flexible separation between the reporter and the conjugation site. Molecular imaging and diagnostic reagent development teams use Azide-PEG12-Tos to streamline probe construction, allowing rapid exchange of reporter moieties and targeting components via click-compatible coupling.

4. Hydrogel and Biomaterial Functionalization

Azide-PEG12-Tos is used to functionalize hydrogels, scaffolds, and other biomaterial matrices by providing azide groups that can be subsequently linked to alkyne-bearing crosslinkers, bioactive motifs, or detection handles through click chemistry. The PEG12 linker contributes to improved water compatibility and helps maintain reactive-group accessibility within hydrated polymer networks. Biomaterials researchers and industrial R&D groups commonly employ Azide-PEG12-Tos to create customizable material surfaces and embedded labeling sites for downstream assay development and materials characterization.