Rationally Modulate the Oxidase-like Activity of Nanoceria for Self-Regulated Bioassays

One of the current challenges in nanozyme-based technology is to rationally control the enzyme mimicking activities with suitable modulation strategies to mimic the complexity and functions of natural systems. In this regard, nanoceria has recently emerged as a promising nanozyme because of its unique enzyme mimicking properties. Herein, we demonstrated that the oxidase-like catalytic activity of nanoceria was rationally modulated in situ via proton-producing/consuming enzyme-catalyzed bioreactions, which formed the basis of self-regulated bioassays for determining the corresponding enzyme activity, as well as other important targets, such as nerve agents, drugs, and bioactive ions. More interestingly, the oxidase-like activity of nanoceria was cooperatively modulated with the aid of adenosine triphosphate, thus improving the analytical performance of such self-regulated bioassays. The current study not only demonstrated regulatory strategies to modulate the nanozymes’ activities, but also established a facile approach to designing self-regulated bioassays.