Voltammetric sensing of heavy metals for global water security: a critical materials perspective on field-deployable monitoring platforms

Heavy metal contamination necessitates portable, sensitive voltammetric sensors. This review assesses electrode interface engineering using MOFs, COFs, and carbon nanocomposites, connecting structural attributes (porosity, redox sites, conductivity) to sensitivity, selectivity, and limit of detection. Integration with microfluidics and edge-deployable machine learning enables autonomous monitoring, yet challenges matrix interference, fouling, model transferability, and standards lack persistence. A research roadmap for robust, field-deployable sensors for decentralized water quality surveillance is outlined.