Recent progress of electrochemical sensors for accurate detection of heavy metal ions in water: A comprehensive review

Water pollution represents a critical global environmental challenge, with heavy metal ions constituting a major class of contaminants. These toxic ions enter the human body through multiple pathways, including the consumption of contaminated drinking water, dermal contact, and bioaccumulation in the food chain. Once introduced, they pose severe health risks due to their high toxicity, strong bioaccumulation potential, and slow excretion rate. Such characteristics enable them to accumulate over time, creating long-term threats to both ecosystems and public health. Addressing these risks requires the development of highly sensitive, accurate, and reliable detection methods to monitor and identify heavy metal pollutants effectively, thereby ensuring environmental monitoring and public health protection. The growing prominence of electrochemical sensing devices in the identification and quantification of toxic metal ions is attributed to their low cost, high selectivity, exceptional sensitivity, and ability to achieve very low detection limits. This review provides a comprehensive overview of recent developments in electrochemical sensing platforms for monitoring heavy metals in aqueous environments and identifies emerging directions for future research. The review is structured to first examine electrode fabrication strategies, detailing the properties of electrodes and the characteristics of electrodes produced through various methods. Next, it reviews research progress concerning the modification of electrodes, emphasizing a variety of modifying materials, including inorganic compounds, organic frameworks, and biomaterials. Subsequently, progress in the supporting analytical frameworks is discussed, including signal recognition, data processing, and predictive modeling algorithms that enable intelligent analysis. Finally, current trends in electrochemical sensing are summarized, and perspectives are offered for the development of novel electrochemical sensor technologies for reliable and precise detection of heavy metal ions.