MXenes and their composites for high-performance detection of pharmaceuticals and pesticides: A comprehensive review

The increasing concerns over environmental pollution and human health hazards caused by pesticides and pharmaceutical residues have driven significant research into the development of highly sensitive and selective electrochemical sensors. MXenes, a class of two-dimensional (2D) transition metal carbides and nitrides along with MXene-based composites, have emerged as promising candidates for electrochemical sensing due to their unique physicochemical properties, including high electrical conductivity, large surface area, hydrophilicity, and tunable surface chemistry. Herein, we have comprehensively discussed the role of MXenes and their composites in the electrochemical detection of drugs and pesticides. Further, they can be classified based on their structural dimensions and explore their fundamental properties, including conductivity, electrochemical stability, mechanical integrity, and chemical reactivity, which govern their sensing performance. However, MXenes can be easily oxidized and undergo gradual structural degradation, which may impact performance over a long time. Therefore, the need for MXene-based composites is highlighted to address the limitations of pristine MXenes and enhance their selectivity, stability, and sensitivity for detecting trace-level analytes. The recent advancements in MXenes modified electrochemical sensors for detecting pesticides and drugs, critically analyzing their sensing mechanisms, detection limits, and response times.