Versatile MXenes as electrochemical sensors for heavy metal ions and phenolic moiety-containing industrial chemicals: recent development and prospects

MXenes and their hybrid materials, with good physicochemical traits, have exhibited excellent performance across numerous applications. MXenes with pre-eminent features, namely, facile surface modifications, functionalization, larger-specific surface area, and conductivity, transcend the limitations of sensor devices. MXene nanomaterials are ideal candidates for use as modifying agents in electrochemical (EC) sensor fabrication. Hence, in this review article, we provide insights into the potential of MXene-based materials for EC sensors compared to conventional materials. At first, we discuss the fundamentals of EC sensors, followed by an introduction to the physicochemical properties of MXene as an efficient working electrode modifying agent that acts as a direct transducing material. The review discusses the notable characteristics and fundamental working principles of EC sensor devices and the significance of surface modification during the fabrication of MXene-based sensors. The article emphasizes advanced sensors and outlines prospects in the field for target analytes of interest: heavy metal ions (HMIs) and phenolic moieties containing toxic molecules. A comprehensive summary of recent developments in MXene-based EC sensors for the molecules mentioned above is critically reviewed, encompassing sensor device fabrication approaches, enhanced properties, results, and discussion. The effect of different secondary organic and inorganic compounds, including carbonaceous materials, polymers, and metallic nanoparticles, on the sensing performance of MXenes is analyzed through EC techniques. Finally, we conclude by outlining the opportunities and obstacles associated with MXene-based EC methods, addressing implications for future directions for progressive research in this field. We believe this review will provide valuable information for those exploring nanomaterials to develop EC sensors.