Emerging insights into the use of carbon-based nanomaterials for the electrochemical detection of heavy metal ions

A number of water bodies worldwide are contaminated due to the disposal of toxic chemicals from anthropogenic activity, with many of these pollutants entering the supply chain for drinking water. Heavy metal ions (HMIs) are the most challenging pollutant entering natural and anthropogenic environments due to their non-biodegradability, toxicity, and ability to biologically accumulate in ecological systems, thus they pose a major risk to human health. Rapid industrialization and technological developments are expected to further exacerbate this problem. To effectively address this issue, robust, sensitive, and selective electrochemical sensing technologies are required to enable the rapid detection of hazardous contaminants. In this respect, the unique properties of carbon nanomaterials offer the potential for the fabrication of effective tools for routine sensing and biosensing applications. The current review aims to highlight recent advances in the design and development of carbon-based nanomaterials for the efficient electrochemical detection of HMIs. In particular, the toxic impact of HMIs is summarized. Immobilization methods, sensing mechanisms, modifications, advantages, and disadvantages of carbon nanomaterials for use in the electrochemical detection of HMIs are explicitly discussed. Significantly, we emphasized the role of carbon-based electrode materials in the electrochemical on-site detection of HMIs. Potential challenges and future prospects for the use of carbon-based nanomaterials in electrochemical detection are also addressed based on research developments and current experimental proficiency. The overall goal is to improve the understanding of carbon nanomaterial-based sensing strategies for the detection of HMIs, thus prompting the future development of nanocomposites and sensing approaches for electrochemical devices that can effectively detect HMIs for environmental protection purposes.