Chemical sensing of heavy metals in water

Heavy metals are carcinogenic in nature and adversely affect DNA, proteins, and lipids by producing free radicals that lead to severe health and environmental problems. Therefore in order to provide clean and safe water sources and sustainable environment to the public, the development of fast and reliable sensory systems to monitor heavy metals is critical. The water quality monitoring typically requires massive, advanced, and costly laboratory-based methods such as absorption spectrometry, inductively coupled plasma MS, X-ray fluorescence, ion chromatography ultraviolet visible spectroscopy, atomic emission spectrometry, etc., to accurately assess water toxicity. Thus there has been intense research interest in developing chemical sensors for heavy metals in water. In this chapter, first, an introduction of heavy metals in water and traditional heavy metal monitoring technologies are presented. Then, toxicity ranges of heavy metals and their toxicity mechanisms on cell are introduced. The principle of various chemical sensors for heavy metals in water are also presented and their performance evaluated. Finally, current trends and future states of heavy metal monitoring are highlighted.