Redox-Responsive Ferrocene-Containing Polymer Capsules Fabricated via Interfacial Photo-cross-linking

Stimulus-responsive polymer capsules serve as versatile platforms for controlled release and self-healing materials. Herein, we report the development of redox-responsive polymer capsules fabricated from a copolymer of 2-cinnamoylethyl acrylate and vinylferrocene utilizing the interfacial photo-cross-linking reaction of the photoreactive polymer particles. By employing interfacial photo-cross-linking, we successfully construct robust polymer capsules containing the ferrocene group at the shell layer. A distinctive feature of this system is the capability to encapsulate fluorescent cargos not only via conventional organic solvent exchange but also within a purely aqueous medium by leveraging the redox-dependent swelling behavior of the polymer shell. Release profiles demonstrate that the capsules remain stable under reducing conditions yet undergo rapid cargo release exclusively in the presence of an oxidant. These findings establish a versatile route to smart, oxidation-responsive carriers suitable for applications requiring solvent-free loading and targeted delivery.