N-(Propargyl-PEG4)-N-bis(PEG4-acid) | CAS 2093153-09-2

N-(Propargyl-PEG4)-N-bis(PEG4-acid) is a PEG-based click chemistry reagent featuring a terminal alkyne for copper-catalyzed azide–alkyne cycloaddition (CuAAC) and multiple PEG4-acid handles that support aqueous compatibility and downstream conjugation workflows. The amphiphilic, multi-PEG architecture is commonly leveraged to improve solubility and reduce nonspecific interactions when building modular bioconjugates, imaging probes, and functionalized biomaterials. As a reagent designed for surface and molecular labeling, it is frequently used to introduce an alkyne “click handle” into PEGylated platforms prior to azide-reactive coupling.

1. PEGylated Biomolecule Labeling

N-(Propargyl-PEG4)-N-bis(PEG4-acid) is used to install a defined propargyl/alkyne functionality into PEG-rich biomolecule conjugates where aqueous stability and controlled spacing are important. Researchers commonly incorporate this reagent into labeling strategies for proteins, peptides, and nucleic-acid associated constructs that are subsequently coupled to azide-bearing partners using CuAAC. The PEG4-acid functionality supports solubilizing and handle-organization roles in complex conjugation schemes, helping maintain colloidal stability during buffer exchanges and purification steps typical of research-grade bioconjugation workflows.

2. Targeting Ligand Conjugation Platforms

N-(Propargyl-PEG4)-N-bis(PEG4-acid) is well suited for constructing modular targeting or affinity platforms by providing an alkyne-bearing PEG spacer that can be clicked to azide-functional ligands or targeting moieties. In molecular imaging and chemical biology tool development, this reagent is often used to tune linker length and hydrophilicity, which can influence accessibility of the conjugated ligand on the final probe scaffold. The multi-PEG design supports iterative assembly of multi-component constructs, such as ligand-decorated nanoparticles or polymeric carriers, where azide partners are introduced at later stages to preserve functionality during intermediate processing.

3. Surface and Material Functionalization

N-(Propargyl-PEG4)-N-bis(PEG4-acid) is applied in the functionalization of biomaterials and surfaces that require stable, water-compatible presentation of a click-reactive alkyne group. Materials scientists use this reagent to incorporate PEG-based spacing layers that help reduce aggregation and nonspecific adsorption while enabling subsequent CuAAC coupling to azide-modified coatings, linkers, or biomolecule layers. Typical downstream outputs include functional hydrogels, polymer films, and bead-based platforms where controlled surface reactivity is needed for reproducible labeling and immobilization of azide-bearing reagents.

4. Multivalent Probe and Imaging Reagent Building

N-(Propargyl-PEG4)-N-bis(PEG4-acid) supports the assembly of multivalent chemical probes by serving as a PEGylated click handle that can be coupled to azide-functional reporter components. In molecular imaging reagent development and chemical biology assays, the PEG4-rich environment provided by this reagent helps maintain probe solubility and helps manage steric effects when multiple conjugation events are performed. By enabling stepwise coupling to azide-tagged reporters, this reagent fits common workflows that require modular construction of complex probe architectures without exposing sensitive components to premature coupling conditions.