Microplasma-Synthesized Ce/Fe-Mof with Oxygen Vacancy: Toward Multiple Enzyme-Like Activities and Rapid Total Antioxidant Capacity Assessment in Agricultural Products

Abstract

The detection of total antioxidant capacity (TAC) plays a significant role in assessing overall antioxidant capacity, predicting the risk of chronic diseases, guiding dietary and nutritional interventions, and studying the effectiveness of antioxidants. However, rapid total antioxidant capacity assessment with high sensitivity and stability remains a challenge. In this study, Ce/Fe-MOF with abundant oxygen vacancy was synthesized using microplasma for determination of TAC. The microplasma synthesis method was fast (30min) and economical. The oxygen vacancy and collaboration between iron and cerium of Ce/Fe-MOF not only enhanced the efficiency of the catalyst but also imparts multiple enzyme-like properties: peroxidase-like, oxidase-like, and superoxide dismutase mimetic activities. Thus, a simple colorimetric assay was established for determination of TAC in vegetables and fruits with short analysis time of 15 min, good linear range of 2-60 μM and low detection limit of 1.3 μM, which is promising for rapid TAC assessment in agricultural products.

Keywords: Bimetallic MOF, Microplasma, Multiple enzyme-like activities, Total antioxidant capacity, Colorimetric sensor