Optoelectronic MXene quantum dots: frontiers in sensor technology for next-generation diagnostics and environmental monitoring

MXene QDs have garnered the attention of established as well as budding researchers as a new class of nanomaterial due to their exceptional properties and wide applicability. Advancements in nanotechnology and materials science have led the discovery of these, and explorations of their exceptional physicochemical characteristics have positioned them as a cutting-edge nanomaterial with immense potential for future innovation. This review explores the different aspects of MXene QDs, including fundamentals, functionalization, and the doping of precursors. The unique properties, including structural, electronic, optical properties, and biocompatibility, making these promising candidates for use in optoelectronic devices have been thoroughly discussed. The different methods used to formulate MXene QDs into functional versions, including ball milling, pyrolysis, molten salt, hydrothermal, and solvothermal synthesis, and ultrasonication have been elaborated on with suitable examples. This article also includes precise yet insightful discussion on the MXene-QD-based sensing of different molecular categories, viz. small molecules, macromolecules, and environmental pollutants. Additionally, this paper provides insightful discussion on sensor fabrication strategies, limits of detection (LODs), linear detection ranges (LDRs), synthetic routes, and real sample detection, along with the detection techniques involved in sensor development in various studies. This article brings fundamental insights ranging from the synthesis of MXene QDs to their deployment to real-time applications in order to understand the overall research scope along with translational bottlenecks from the perspective of future development.