Application of Two-Dimensional MXene materials in sensors

Transition metal carbides and nitrides/carbonitrides (MXenes) with satisfactory conductivity, high specific surface area and excellent hydrophilicity have attracted the attention of many researchers in the field of electrochemical sensors in recent years. Etched MXenes usually show an accordion-like morphology; moreover, monolayer MXenes exhibit better electrical conductivity and mechanical properties. The electronic and chemical properties of MXenes can be significantly changed by means of compounding, hybridization and modification. MXenes with large surface areas can be used in biosensors as carriers for recognition elements to achieve direct electron transfer to target analytes. In addition, MXenes exhibit excellent biological compatibility so that they can be incorporated into biological receptors without affecting biological activity. MXenes can be combined with other metal oxide nanoparticles to expand the electrode surface area while reducing the overpotential effect in the electroanalysis process to enhance catalytic activity. MXene-based sensors for detecting strain, pressure, temperature, gas, various biomarkers, and some environmental pollutants, and for use in other major research fields are summarized. The future challenges in MXenes research, development and applications of electrochemical sensing are discussed.