Dopamine-PEG-Acetic Acid， Chemical Structure Characteristics of Dopa Polyethylene Glycol Acetic Acid Conjugate

1、 Chinese name
The Chinese name for Dopamine PEG Acetic Acid is usually Dopamine PEG Acetic Acid Conjugate, abbreviated as Dopamine PEG Acetic Acid. This molecule consists of three main parts: dopamine, PEG segment (Polyethylene Glycol), and acetic acid end (Acetic Acid). Among them, dopa provides an active end containing catechins, which can participate in oxidative coupling or surface adsorption; PEG segments provide water solubility and flexible spatial isolation; The acetic acid end provides carboxyl activity, which can be used for further chemical modification or coupling functions.

2、 Chemical structural characteristics

1. Dopamine end

• Dopa is a 3,4-dihydroxy derivative containing catechol hydroxyl (- OH) and primary amino (- NH ₂) groups.

• The catechol structure can form quinone intermediates through oxidation and undergo covalent coupling with thiol or amino groups.

• Dopa can bind to metal, oxide, or biomolecule surfaces through physical adsorption or chemical coupling, providing highly controllable surface functionalization capabilities.

2. PEG segment

• The PEG chain is composed of ethylene glycol repeating units and has flexibility, hydrophilicity, and biocompatibility.

• PEG chains, as water-soluble spacers, can reduce molecular aggregation and non-specific adsorption while maintaining accessibility to the ends of dopa and acetic acid.

• The chain length can be adjusted, affecting the molecular spatial structure and solubility.

3. Acetic Acid Terminal

• The other end of the PEG chain is connected to a carboxyl group (- COOH), which can be coupled with other molecules through esterification or amidation.

• Provide controllable chemical activity for further functionalization in biomaterials, drug carriers, or nanosystems.

• Carboxyl groups are prone to form stable amide or ester bonds, making them suitable for biological coupling reactions under mild conditions.

3、 Molecular characteristics

1. Amphiphilic structure

• The dopamine end provides hydrophobicity or surface adsorption ability, the PEG chain provides water solubility, and the acetic acid end provides chemical activity.

• This amphiphilicity and multifunctionality enable molecules to exhibit excellent performance in self-assembly, surface modification, and nanocarrier construction.

2. Chemical stability and reactivity

• PEG chains provide flexible protection for the ends of dopamine and carboxyl groups, reducing molecular aggregation and non-specific reactions.

• The dopamine end can participate in covalent coupling under appropriate oxidation conditions, while the acetic acid end provides a controllable coupling site through a carboxyl group.

3. Water solubility and biocompatibility

• PEG segments enhance water solubility and biocompatibility, making them suitable for in vitro and in vivo experiments.

• The flexible molecular structure reduces immunogenicity and non-specific adsorption.

Product Name: Dopamine PEG Acetic Acid

Purity: 95%+

Characteristic: Solid or liquid

Storage conditions: Dry at -20 ° C and stored away from light

Packaging specifications: 50mg 100mg 250mg 500mg (provided upon request)

Manufacturer: Qiyue Biotechnology

About Us

Qiyue Biotechnology provides customized services for near-infrared fluorescent cyanine dye labeling of various functional groups, such as active esters (NHS esters), maleimide (MAL), azide (N3), alkyne, etc., which facilitate covalent coupling with proteins, peptides, polysaccharides, antibodies, oligonucleotides, nanoparticles, etc. Multiple functional groups can be selected to precisely bind with target molecules, achieving fluorescent modification of proteins, peptides, antibodies, nucleic acids, or nanomaterials. In addition, Qiyue Biotechnology also provides customized dye labeling services, including peptides, proteins, small molecules, sugars and other types of markers, to meet users' personalized applications in scientific research, imaging and other fields.

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For scientific research only, cannot be used for human experiments AXC.2025.09