Control of a catalytic activity of gold nanoparticles embedded in DNA hydrogel by swelling/shrinking the hydrogel's matrix

Hypothesis: By incorporating catalytically active nanoparticles into polymeric hydrogel one can tune the catalytic activity of such a hybrid material by affecting the state of polymer matrix.

Experiment: Herein, hybrid hydrogel was prepared by metallization of DNA cross-liked hydrogel via absorption of gold precursor and reduction by NaBH4, and its catalytic activity under various swelling ratio was studied spectroscopically.

Findings: Catalytic activity of Au nanoparticles in hydrogel was shown to depend drastically on a swelling degree of hydrogel easily controlled by a change in an ionic strength of solution. Increase of the catalytic reaction rate was proportional to the volume of hybrid hydrogel indicating that diffusion of reactants toward catalytic centers inside hydrogel is crucial for the efficient catalysis by soft-matter-based hybrid material.