Recent advances in MXene nanozyme-based optical and electrochemical biosensors for food safety analysis

The importance of nanotechnology is increasing every day in different fields and, especially, the application of nanomaterials has attracted considerable attention in food safety. Among different nanomaterials, MXenes, which are two-dimensional (2D) transition metal-based layered materials made of nitrides and carbides, have revolutionized various fields as a cutting-edge scientific discovery in nanotechnology. These materials have been widely used in the structure of biosensors and sensors due to their excellent metallic conductivity, mechanical stability, optical absorbance, good redox capability, and higher heterogeneous electron transfer rate. In particular, the application of MXenes as nanozymes has highlighted their high performance to a great extent in biosensor domains. The growing interest in these nanozymes is attributed to their specific physicochemical features. The key enzymatic features of these materials include activities similar to oxidase, peroxidase, catalase, and superoxide dismutase. In this review, initially, several common synthesis methods of MXenes are presented, emphasizing their significant role as nanozymes in constructing efficient sensors. Subsequently, several common applications of MXene nanozymes in food safety analysis are delved into, including the detection of bacteria, mycotoxins, antibiotic residues, and pesticide residues, along with their applications in different electrochemical and optical biosensors. In addition, the gap, limitation, and future perspective of these novel nanozymes in food safety are highlighted.