Green synthesis and characterization of carbon-based materials for sensitive detection of heavy metal ions

Pollution caused by heavy metal ions is becoming an increasingly critical problem every year. Heavy metal ions such as arsenic, cadmium, chromium, lead, and mercury are very important for public health due to their high toxicity. These heavy metal ions are systemic toxicants and are known to cause multiple organ damage even at low exposure levels. Therefore, developing new techniques for rapid, easy, selective, reliable, and low-cost identification of heavy metal ions is crucial. However, conventional sensors designed for the detection of heavy metal ions have many limitations and difficulties. Electrochemical techniques have many advantages over other methods such as being selective, sensitive, reliable, fast, and environmentally friendly. Carbon materials are one of the most effective materials for the detection of heavy metal ions. Carbon materials derived from biomass overcome these challenges and provide better performance to the sensing platform. However, there are still very few reviews focusing on the green synthesis of carbon material-based sensors. Therefore, we present this review to summarize recent developments in the green synthesis of carbon materials and their applications in detecting heavy metal ions. Then, some selected green syntheses of carbon material-based sensor studies developed for heavy metal ions analysis are summarized and tabulated for the last five years (2017–2021). Finally, trends and future perspectives for using environmentally friendly carbon materials in sensor designs are discussed.