ZIF-8 directed templating synthesis of CeO2 nanoparticles and its oxidase-like activity for colorimetric detection

Cerium dioxide nanoparticles (CeO2 NPs) have been applied in various colorimetric detection methods owing to their low cost and impressive catalytic activity. Unfortunately, methods for the synthesis of CeO2 NPs often require harsh conditions and many complicated steps. Thus, robust strategies are needed for the synthesis of CeO2 NPs. In this work, we proposed a facile method for the synthesis of CeO2 NPs based on ZIF-8 NPs templates, under mild conditions. ZIF-8 NPs were used as sacrificial templates that provide an in-box nanocage for CeO2 formation through their alkali surface, without requiring external alkaline additives or stabilizers. Based on the intrinsic oxidase-like activity of CeO2 NPs, colorimetric detection methods for organophosphorus pesticides and oxytetracycline were established.