Electrochemical detection of lead, cadmium, and mercury with selective preconcentration on ligand-modified electrodes

Detecting Metallic Trace Elements (MTEs), especially toxic ones like cadmium, lead, and mercury, remains a key research focus. While methods using aptamers, molecularly imprinted polymers (MIPs), and metal-organic frameworks (MOFs) are gaining attention, electrochemical sensors with organic ligands remain widely studied due to their simple preparation, durability, and reusability. Metal-selective ligands are also increasingly integrated with MOFs and MIPs for enhanced performance. This review examines recent advancements in electrochemical sensors based on metal-ligand complexation over the past seven years, with a focus on ligand design role in sensor efficiency. The first part addresses generic ligands and strategies for achieving sensor selectivity and sensitivity. The subsequent sections review the literature on specific sensors designed for cadmium, lead, and mercury detection. Special consideration is given to sensor stability and repeatability, key parameters for practical applications. The discussion also covers sensor performance in real samples and interference studies, highlighting their relevance for environmental monitoring. • Ligand-modified electrochemical sensors for Pb 2+ , Cd 2+ and Hg 2+ detection. • How selectivity is achieved with these electrochemical sensors. • Latest performance results in terms of sensitivity and selectivity. • Reusability and stability of sensors based on ligand-modified electrodes.