Recent research on MOF and COF-based materials for heavy metal ion detection

Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) are advanced porous materials with tunable porosity, high surface area, and structural versatility, making them ideal for electrochemical and optical biosensing. This review summarizes recent progress in MOF- and COF-based platforms for the detection of toxic heavy metal ions, including Pb 2+ , Cu 2+ , Hg 2+ , As 3+ , As 5+ , Cr 3+ , and Cr 6+ , which pose significant environmental and health risks. Integration of these frameworks with conductive nanomaterials, functional groups, and redox-active sites enhances electron transfer, increases active site density, and lowers detection limits. Various synthetic approaches for pristine frameworks and their composites are discussed, along with mechanistic insights into electrochemical and optical detection strategies. By consolidating state-of-the-art developments, this work provides a scientific basis for the rational design of next-generation MOF- and COF-based sensors, enabling the development of portable, cost-effective, and ultrasensitive tools for environmental monitoring and biomedical applications. • MOF-based sensors show superior performance owing to their redox activity, tunable porosity, and high surface area. • Pristine MOFs and MOF–conductive composites enable multifunctional sensing platforms for heavy metal ion detection. • Recent advances enable electrochemical detection of toxic metal ions, crucial for environmental monitoring. • The review discusses diverse sensing strategies, providing detailed insights into their principles and advantages.