Air-Derived Inhibitor of Nanozymes

Nanozymes are functional nanomaterials with enzyme-mimicking activities, which have found wide applications in various fields. Investigation on nanozyme inhibitors not only helps to apply nanozymes in a controlled manner but also deepens our insight into the catalysis mechanism. Herein, we report an inorganic ion inhibitor, HCO 3 –, which can significantly inhibit the alkaline phosphatase-mimicking activities of Ce 6 cluster-based metal–organic framework (Ce-MOF) nanozymes. The inhibition of adsorption of the negatively charged fluorescence sodium on Ce 6 clusters in Ce-MOF nanoparticles (NPs) by HCO 3 – proves that HCO 3 – ions occupy and deactivate Ce 6 clusters (i.e., catalytic active sites), leading to the activity inhibition of Ce-MOF nanozymes. Tris(hydroxymethyl)aminomethane hydrochloride (Tris–HCl) buffer is widely employed as the alkaline reaction medium. HCO 3 – ions can be formed in Tris–HCl buffer through adsorption of CO 2 in the air during storage in a sealed tube, which significantly inhibits the activity of Ce-MOF nanozymes. To our knowledge, this study is the first to demonstrate an air-derived inhibitor of nanozymes.