Nanozyme-Triggered DNA Release from Alginate Films

Alginate hydrogel thin films of different compositions were electrochemically produced at an electrode surface, and their interfacial reactions were studied for biomolecule release. Nanozyme catalytic species represented by Au nanoparticles were used to trigger biomolecule release from an Fe³⁺-cross-linked alginate hydrogel film upon receiving a glucose signal. The oxidase-mimicking reaction catalyzed by Au nanoparticles resulted in the production of H₂O₂, which yielded free radicals through a Fenton-type reaction in the presence of iron cations. The generated free radicals resulted in degradation/dissolution of the alginate matrix and stimulated the release of entrapped DNA molecules. The systematic study addressed the issues of the uncontrolled leakage of the DNA molecules from alginate hydrogel and demonstrated the signal-triggered DNA release in systems with various configurations, ranging from a simple addition of H₂O₂ to the bulk solution to the in situ production of H₂O₂ by the nanozyme coentrapped in the alginate film. The present study adds an additional feature to the multioperational functions of nanozymes, representing their use in signal-controlled biomolecule-releasing systems.