Sensor array based on Co-based nanozymes for rapid identification of multiple synthetic phenolic antioxidants

Synthetic phenolic antioxidants are a class of compounds with phenolic structure prepared by chemical synthesis, which are mainly used in foods, plastics, and rubbers to slow down the oxidation process, but excessive consumption may pose a threat to human health. However, it is difficult to achieve rapid and efficient detection of multiple synthetic phenolic antioxidants by existing methods. To circumvent this issue, we prepared a novel nanozyme sensor array based on two cobalt-based nanozymes (Co-MOFs and CoOOH) with high oxidase-like activity for rapid differentiation of six synthetic phenolic antioxidants, including propyl gallate (PG), tertiary butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), 2,6-Di-tert-butyl-4-hydroxymethylphenol (BHT-OH) and 3,5-Di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH). Wherein, the obtained Co-MOFs and CoOOH nanozymes showed good oxidase-like activity and exhibited high stability. Of interest, the synthetic phenolic antioxidants could differentially modulate the oxidase-like activities of Co-MOFs and CoOOH nanozymes, which could be converted into colorimetric signals. The proposed nanozyme sensor array can characterize six synthetic phenolic antioxidants and their multi-component mixtures in the concentration range of 0.015-1 mM. Our findings present a straightforward and efficient approach for identifying and quantifying synthetic phenolic antioxidants, advancing the development of sensor array technologies for detecting diverse contaminants in environmental monitoring and food safety applications.