New frontiers and prospects of MXene-based photoelectrochemical sensing system for detection of pollutant in food and environment

Food and environment pollution is an international concern. It is, therefore, necessary to develop effective and fast techniques for determining contaminants in food samples and water. In this direction, 2D metal carbides and nitrides (MXenes), due to their rich surface functionalities, boosted effective surface area, and tunable physicochemical features have presented favorable performances in biosensing flatlands. This work concentrated on the role of MXenes in photoelectrochemical (bio)sensors, whose popularity has increased significantly in the last decade because of their functional structure and unique properties, such as low background signal, easy operation, high sensitivity, and inexpensive instrument. The MXene's effect on photoelectrochemical sensing procedures is reviewed comprehensively. In addition, the MXene's synthesis with a green strategy and incorporation of these processes into photoelectrochemical (bio)sensing applications are considered in depth, which provides new thoughts for the preparation of MXenes and the innovation of composite materials in the future PEC devices. Moreover, this work outlines the up-to-date trends in MXene-derived photoelectrochemical (bio)sensors for onsite sensing of agri-food contaminants. Mainly, we tried to provide a summary of various strategies used for target molecule analysis (pesticides, biotoxins, veterinary drug, and heavy metal ions). Finally, the challenges and future directions are concluded and depicted.