MXene-based Nanobiosensors for Environmental Pollutant Detection: Recent Advances, Challenges and Future Perspectives

Abstract

MXenes have appeared as a potential variety of two-dimensional materials for environmental biosensing due to their remarkable conductivity, flexible surface chemistry, and large surface area. This article presents an analytical review based on published works covering the last ten years, though it goes beyond previous analyses in scope. This paper takes an integrated approach to the synthesis of MXenes, as well as their surface modifications, biosensing methods, applications of MXenes to environmental monitoring, challenges of commercializing MXenes, and possible areas for future studies. Studies in the literature show that MXene-based nanobiosensors provide superior performance in terms of enhanced sensitivity and selectivity as well as fast responses in detecting various environmental pollutants such as metals, pesticides, microorganisms, drugs, and new organic substances. Additionally, it discusses the effect of synthesis and surface modification on the efficiency of sensors for different applications in environmental monitoring. There are various critical challenges hindering the successful use of MXene-based nanobiosensors in practice. These cover issues such as degradation due to oxidation, low reproducibility, difficulties related to large-scale manufacturing, lack of standardized and regulated fabrication processes, as well as lack of toxicity testing over longer periods of time, which presents hurdles for commercialization and adoption of these devices in practice. All these aspects are discussed in detail in relation to practical environmental monitoring with the aim of identifying gaps in knowledge and technology. Future studies need to focus on achieving the development of oxidation-resistant MXenes, methods of sustainable synthesis, standardized production processes, large-scale manufacturing approaches, and complete environmental safety assessments. Solving these issues will allow MXenes-based nanobiosensors to emerge from the laboratory setup and be used in environmental monitoring in practice.