Advances of Metal-Organic Framework Composites in Electrochemical Detection of Environmental Pollutants

With the continuous development of science and technology, environmental pollution has become increasingly severe, which makes environmental monitoring crucial. In recent years, electrochemical sensing strategy has attracted wide attention due to its advantages such as low cost, easy operation and fast detection speed. However, the detection performance still faces many challenges such as low sensitivity, high limit of detection and poor selectivity. Metal-organic frameworks (MOFs) is a kind of ordered network porous crystal formed by the coordination bond of organic ligands and metal ions/ion clusters, which can be used to prepare high-performance electrode materials for construction of electrochemical sensors because of their characteristics of large specific surface area, adjustable pore size and diverse structure. However, the poor conductivity and stability of MOFs result in poor electrochemical detection performance, which seriously limits their extensive applications in the field of electrochemistry. Combining MOFs with other functional materials can not only overcome the inherent defects of MOFs but also have the superior properties of both MOFs and functional materials, and the synergistic effect between MOFs and functional materials is conducive to improving the detection performance. Therefore, MOFs composites have been widely used in the electrochemical detection of environmental pollutants. This paper reviewed the applications progress of electrochemical sensors based on MOFs composites (MOFs combine with carbon materials, conductive polymers, metal nanoparticles or MOFs) in detection of environmental pollutants (Pesticides, heavy metal ions, phenolic compounds and nitrites) in the past five years. The prospects and challenges of electrochemical sensors based on MOFs composites for detection of environmental pollutants were also discussed.