Untemplated Resveratrol-Mediated Polydopamine Nanocapsule Formation

Nanocapsules can be designed for applications including drug delivery, catalysis, and biological imaging. The mussel-inspired material polydopamine is a promising shell layer for nanocapsules because of its free radical scavenging capacity, ability to react with a broad range of functional molecules, lack of toxicity, and biodegradability. Previous reports of polydopamine nanocapsule formation have relied on a templating approach. Herein, we report a template-free approach to polydopamine nanocapsule formation in the presence of resveratrol, a naturally occurring anti-inflammatory and antioxidant compound found in red wine and grapes. Synthesis of nanocapsules occurs spontaneously in an ethanolic resveratrol/dopamine·HCl solution at pH 8.5. UV–vis absorbance spectroscopy and X-ray photoelectron spectroscopy indicate that resveratrol is incorporated into the nanocapsules. We also observed the formation of a soluble fluorescent dopamine–resveratrol adduct during synthesis, which was identified by high-perfo...