Design and engineering of 2D MXenes for point-of-care electrochemical detection of bioactive analytes and environmental pollutants

MXenes have emerged as a unique and fast-expanding family of two dimensional (2D) nanomaterials containing early transition metal carbides, nitrides or carbonitrides. They have excellent physical, electrochemical, mechanical and catalytic properties and hence, have been exploited in a wide range of applications such as nanoelectronics, gas separation, photo/electrocatalysis, energy generation and storage, dye adsorption including electrochemical (bio) sensors. Owing to the superior physicochemical characteristics like excellent electrical conductivity, environmental friendliness, large surface area, good hydrophilicity and ease of functionalization, MXenes have advanced as promising materials for the construction of electrochemical sensors/biosensors. This review mainly focuses on MXenes-based electrochemical (bio)sensors towards the effectual detection of environmentally as well as biologically important analytes, which include nitro and phenolic compounds, metal ions, inorganic anions, antipyretics, biomolecules, neurotransmitters and small molecules. Moreover, it elaborates on the various synthetic methodologies and design and engineering strategies adopted to evolve and exploit the distinctive properties of MXenes in electrochemical sensing. A special emphasis has been devoted to developing diverse MXenes in order to fabricate innovative electrochemical (bio) sensors to detect various significant analytes. In a nutshell, this review provides a detailed insight of the design and engineering of 2D MXenes for point-of-care electrochemical detection of bioactive analytes and environmental pollutants. It also critically evaluates the recent progressions in various MXene based electrochemical (bio)sensors outlining the diverse analytical techniques, employed towards the detection of the aforementioned analytes.