Nanomaterials in water pollution control: A concise review of electrochemical methods towards heavy metals

This is the authors' abstract. We don't add key points for this paper.

Despite the United Nations (UN) recognizing access to clean drinking water as a basic human right, nearly 2 billion people worldwide have no access to safe drinking water. The rising demand for water due to population growth and global development, as well as water pollution, continues to exacerbate these issues of water scarcity. Water pollution is a worldwide problem that often results in severe health effects, degradation of aquatic ecosystems, and widespread socio-economic and food chain disruptions. Therefore, there is an urgent need for accurate and portable instruments capable of detecting and monitoring water pollutants onsite and in real-time, enabling the timely identification of pollutants and the implementation of prompt mitigation strategies. Exploiting the unique properties of nano-sized materials in combination with electrochemical techniques offers an effective approach to detecting water pollutants with outstanding sensitivity, selectivity and in real-time. Key findings from this review highlight ultra-low detection limits achieved by sensors such as Fe 3 O 4 NPs/MWCNTs/GCE (Cd 2 + : 0.006 ppb, Pb 2+ : 0.002 ppb), GQDs/AuNPs/GCE (Hg 2+ : 0.004 ppb), and AgNPs/GCE (As 3+ : 0.0096 ppb) which demonstrate the efficacy of these methods. Hence, this concise review focuses on sensor design, emphasizing the role of nanocomposites in enhancing detection capabilities and their potential to combat heavy metal (HM) ion pollution in various water systems. • Glassy carbon and screen-printed electrodes provide stable platforms for sensor fabrication. • Gold nanoparticles demonstrate superior electrocatalytic activity in heavy metal ion detection. • Nanocomposite-based electrochemical sensors achieve ultra-low detection limits for heavy metals. • Advanced electrode modifications enhance selectivity, stability, and real-time heavy metal ion detection.