MOF-based Electrochemical Sensors for Toxic Anions

Abstract

Currently, the world is facing a serious environmental crisis, largely due to rapid industrialization. Although the industrial revolution in the last two decades has led to better economies, it has been a primary reason for water pollution as well. Toxic materials including dyes, pigments, metal cations, and anions are commonly used in industries and are directly disposed of in water canals and rivers via industrial effluents. Among these pollutants, toxic anions such as chlorides, sulfates, fluorides, phosphates, arsenates, and cyanides are potentially damaging for human and aquatic life. Monitoring and detection of these anions is an important area of environmental research and researchers have developed several techniques for this purpose. Electrochemical sensing has now been successfully used for the analysis of toxic anions. Different types of materials have been designed and applied as electrochemical sensors for the detection of anions from industrial effluents. Metal-organic frameworks (MOFs) are a class of materials, with a three-dimensional structure, high surface area, aligned geometry, distinct porosity, and tunable surface morphology. MOFs are also being widely used as electrochemical sensors for toxic anions with high selectivity and sensitivity. MOFs are used as composites with other materials including carbon-based materials, polymers, metal/metal oxides, metal, and sulfides. Diversity in MOFs and their combinations is due to the availability of a variety of ligands, synthesis methods, and tunable surface chemistry. Owing to these attributes, MOFs can be used as electrochemical sensors for toxic anions at an industrial scale to monitor environmental pollution.