Conjugating Carboxylic Acid Functionalized Gold Nanoparticles, unlike other gold nanoparticles, are pre-ready for covalent conjugation. The carboxlic acid groups on the surface of the gold nanoparticles are easily reacted with primary amines via a condensation reaction which yields strong amide bonds. Usually, this is achieved by using a water-soluble carbodiimide linker such as EDC.

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