APN-C3-PEG4-alkyne | CAS 2183440-36-8

APN-C3-PEG4-alkyne is a PEGylated alkyne-bearing click chemistry reagent designed for copper-free or copper-catalyzed conjugation workflows, enabling efficient attachment of the alkyne handle to complementary azide-functional partners. The structure combines a defined C3 spacer with a PEG4 solubilizing segment, supporting aqueous compatibility and reduced nonspecific interactions in labeling and biomolecule modification. As a research-grade alkyne reagent, it is commonly selected for building modular conjugates used in chemical biology, biomaterials functionalization, and molecular imaging probe assembly.

1. Biomolecule Labeling

APN-C3-PEG4-alkyne is widely used to introduce an alkyne handle onto biomolecules and biomolecule-derived constructs for subsequent click conjugation with azide-bearing targets such as proteins, peptides, glycans, or nucleic-acid components. The PEG4 segment improves solubility and helps maintain conjugate compatibility across labeling buffers, which is valuable when preparing fluorescent or affinity-tagged reagents for assay development. Researchers often incorporate APN-C3-PEG4-alkyne into modular labeling strategies to generate defined conjugate libraries for mechanistic studies, reagent optimization, and orthogonal tagging workflows.

2. Surface And Hydrogel Functionalization

APN-C3-PEG4-alkyne supports click-based functionalization of polymer surfaces and hydrogel materials by providing a stable alkyne moiety for reaction with azide-functional crosslinkers or capture ligands. The C3 spacer and PEG4 chain can help present reactive groups with improved accessibility, which is important when immobilizing biomolecules at material interfaces for biosensing, cell-interaction studies, or extracellular-matrix-mimetic platforms. This reagent is frequently used in materials chemistry pipelines where researchers need reproducible surface chemistry for attaching bioactive or recognition elements without extensive redesign of the underlying material scaffold.

3. Molecular Imaging Probe Building

APN-C3-PEG4-alkyne is commonly incorporated as an alkyne building block in the assembly of imaging and detection probes that rely on azide-reactive components, including fluorophores, affinity tags, or imaging-reporting motifs. The PEG4 linker contributes to aqueous handling and can reduce aggregation tendencies during probe synthesis and formulation, supporting robust probe preparation for in vitro imaging workflows. In probe development, APN-C3-PEG4-alkyne is valued for its modularity, allowing rapid exchange of the azide partner to generate structurally related probe series for optimization of labeling density and conjugate architecture.

4. Diagnostic Reagent Conjugation

APN-C3-PEG4-alkyne is used to create conjugated diagnostic reagent components in research and industrial assay development settings, where alkyne-azide click handles enable controlled attachment of recognition elements to reporter scaffolds. The PEG4 spacer supports conjugate solubility and can help manage steric effects when coupling to bulky azide-bearing reagents such as labeled antibodies, aptamer constructs, or enzyme/particle conjugates used in assay formats. Teams building multiplexed or modular assay reagents often select APN-C3-PEG4-alkyne to streamline the manufacturing of consistent conjugate intermediates that can be carried through downstream assay assembly steps.