t-Boc-Aminooxy-PEG2-azide | CAS 252378-68-0

t-Boc-Aminooxy-PEG2-azide is a PEG-based azide click chemistry reagent that incorporates an aminooxy functional group protected as a Boc carbamate and an azide handle for bioorthogonal conjugation. As an azide-bearing linker, it is commonly selected for strain-promoted azide–alkyne cycloaddition (SPAAC) workflows and related click-enabled labeling strategies, where the PEG spacer improves solubility and reduces nonspecific interactions in aqueous systems. The combination of a protected aminooxy group with an azide moiety makes it particularly useful when researchers need a stable, modular intermediate for downstream conjugation to biomolecular targets, surfaces, or imaging scaffolds.

1. SPAAC Probe Conjugation

t-Boc-Aminooxy-PEG2-azide is frequently used as a PEGylated azide building block for SPAAC labeling of alkyne-functional probes, including fluorescent tags, affinity reagents, and imaging handles. The PEG2 spacer supports robust aqueous handling and helps maintain probe accessibility during conjugation, which is valuable when attaching labels to proteins, peptides, or polymeric carriers. In typical workflows, the azide is kept as the click-reactive handle while the aminooxy functionality provides a secondary handle for subsequent oxime-type coupling strategies after deprotection.

2. Biomolecule Labeling Linkers

t-Boc-Aminooxy-PEG2-azide serves as a practical linker for constructing multifunctional bioconjugates in chemical biology and biomaterials research. Researchers often incorporate this reagent to introduce both a clickable azide for orthogonal attachment and an aminooxy group that can be converted into an oxime-forming functionality for selective conjugation to aldehyde-bearing biomolecules or glycans. The protected aminooxy group allows controlled activation timing, enabling sequential assembly of complex conjugates such as labeled enzyme substrates, receptor-binding probes, or engineered protein conjugates used in mechanistic studies and assay development.

3. Surface and Material Functionalization

t-Boc-Aminooxy-PEG2-azide is widely applied in the functionalization of polymeric materials, hydrogel networks, and solid supports where azide-based click attachment to alkyne-functional surfaces enables spatially defined modification. The PEG2 segment improves compatibility with water-rich environments and can mitigate aggregation during surface coupling steps, which is advantageous for reproducible coating and patterning workflows. After immobilization via click chemistry, the aminooxy functionality offers a route to further derivatization through oxime chemistry, supporting the creation of multistep material platforms for biosensing and molecular capture.

4. Multihandle Imaging Reagents

t-Boc-Aminooxy-PEG2-azide is used to assemble multihandle imaging reagents that require orthogonal conjugation points for modular probe construction. The azide enables rapid attachment to alkyne-bearing imaging dyes or reporter scaffolds through click chemistry, while the aminooxy group supports downstream coupling to aldehyde-functional imaging targets or biomolecular carriers. This dual functionality is particularly relevant for researchers building combinatorial libraries of labeled probes, where consistent linker behavior and aqueous compatibility improve the practicality of probe synthesis and iterative optimization.