Optical chemosensors based on metal organic frameworks for selective detection of hazardous pollutants: A review

Abstract

The development of an appropriate selective chemical sensor for the detection and quantification of environmentally hazardous substances, such as heavy metals, has seen a substantial demand in scientific interest. Because optical changes occur when luminous metal-organic frameworks (LMOFs) interact with the analyte of interest, they have recently received a lot of attention as effective chemosensors. Metal-organic frameworks (MOFs), also known as porous coordination polymers (PCPs), are the crystalline compounds with the biggest pores. They are made up of metal ions linked to organic ligands. Because of the collective behavior of the functional units, controlled integration of MOFs and functional materials results in the fabrication of new multifunctional composites that outperform those of the separate components. Their design flexibility, as well as tunable and homogeneous pore sizes, make them appealing materials for a wide range of applications. Various methodologies, including the hydro/solvothermal technique, microwave, electrochemical, and mechanochemical processes, have been used to create a range of unique structures. The methodologies employed in the design of MOFs are critical in terms of the targeted application. Some of the promising applications of the MOFs are catalysis, energy storage, adsorption, drug-delivery systems, membrane separation, non-linear optics, gas storage and sensing towards various target components, including small molecules, solvents, pesticides, explosives, and biological markers. This review gives an overview of metal-organic frameworks, nomenclature, structure, synthesis methods, types of luminescent MOFs, the common sensing mechanisms, and application in sensing hazardous pollutants.