ABSTRACT
The growing need for accurate and timely environmental pollution monitoring and detection requires novel sensing techniques with superior performance like high selectivity, excellent sensitivity, and reliability. Metal-organic frameworks (MOFs) represent an advanced class of organic-inorganic hybrid porous materials formed by a strong coordination bond between the inorganic nodes/metal ions and organic linkers. MOFs are promising sensing platforms owing to their eccentric structures and properties, namely, large surface area, unlimited tunability, high porosity, reversible adsorption, and the presence of highly dense active sites. MOFs have been widely reported to detect environmental contaminants like anions, heavy metal ions, organic compounds, and gases, due to such unique features. Selectivity is one of the most critical sensing parameters because of the interference caused due to the presence of diverse interfering molecules, which hinders accurate detection of a target analyte. The cross-sensitivity towards different analytes at given concentrations is compared while determining the selectivity of a particular MOF-based sensor. The superior selectivity of a sensor is based on the typical surface reaction in the presence of target analytes. In addition, the stability of the sensor is a critical parameter for their long-term practical applications. In this chapter, various strategies have been discussed to enhance the active sites to promote surface reactions with the target analytes for MOF-based electrochemical sensors. The different approaches discussed to improve the sensor performance of MOF-based composites include control of structure, morphology, composition, incorporation of functional materials, and encapsulation of nano-catalysts in the pores of MOFs.
