9-(Azide-PEG9-ethylcarbamoyl)nonanoic t-butyl ester

9-(Azide-PEG9-ethylcarbamoyl)nonanoic t-butyl ester is an azide-functional, PEGylated click chemistry building block designed for subsequent strain-promoted or copper-catalyzed azide–alkyne cycloaddition workflows. The reagent incorporates a long, flexible PEG spacer that supports solubility and reduces steric constraints during bioconjugation and surface functionalization. The t-butyl ester motif provides a protected carboxylate handle that can be leveraged when downstream coupling or material immobilization requires controlled presentation of the acidic functionality.

1. Biomolecule Conjugation

9-(Azide-PEG9-ethylcarbamoyl)nonanoic t-butyl ester is used as a versatile azide precursor for attaching PEG-spaced linkers to proteins, peptides, and other biomolecular scaffolds prior to click labeling. Researchers commonly incorporate this reagent when they need an azide-bearing conjugate with improved aqueous compatibility and reduced nonspecific interactions, enabling cleaner downstream coupling to alkyne-functional partners such as fluorescent dyes, affinity tags, or imaging probes. The PEG9 spacer helps maintain accessibility of the azide group, which is particularly valuable for bulky biomolecules and multivalent labeling strategies used in chemical biology and molecular imaging tool development.

2. Surface and Material Labeling

9-(Azide-PEG9-ethylcarbamoyl)nonanoic t-butyl ester supports azide-functional coating and surface modification workflows where PEG-mediated spacing is beneficial for functional presentation. Materials scientists and platform developers use azide-bearing PEG linkers to prepare clickable surfaces for subsequent attachment of biomolecules, ligands, or reporter groups through standardized click chemistry steps. The protected ester functionality provides a convenient route to introduce a carboxylate-bearing linker architecture that can be used to tune surface chemistry and immobilization behavior, including controlled anchoring strategies on polymeric or functionalized substrates.

3. Molecular Imaging Probe Construction

9-(Azide-PEG9-ethylcarbamoyl)nonanoic t-butyl ester is frequently selected for constructing imaging and detection reagents that require a stable azide handle paired with a hydrophilic PEG spacer. Probe developers use this reagent to generate azide-functional intermediates that can be clicked to alkyne-containing reporter motifs, including fluorophores and other signal-generating tags, while minimizing steric hindrance that can reduce labeling efficiency. The PEG9 length is particularly useful when probe performance depends on maintaining probe accessibility and reducing aggregation in complex labeling buffers used for assay and imaging reagent preparation.

4. Diagnostic Reagent Linker Synthesis

9-(Azide-PEG9-ethylcarbamoyl)nonanoic t-butyl ester is applied in the synthesis of diagnostic reagent components where modular linker chemistry is required for consistent conjugation. Reagent developers incorporate PEG-spaced azide linkers to connect capture or reporting elements to alkyne-functional partners in a controlled, stepwise manner, supporting scalable workflows for assay reagent assembly. The combination of an azide click handle and a protected carboxylate architecture allows flexible downstream formatting of linker geometry, which is advantageous for producing conjugates used in biochemical assay development and analytical chemistry platforms.