Nanomaterials as fluorescent sensor and colorimetric sensor for toxic Hg(II) ion: A review

Mercury ion (Hg(II) ion) is one of the most toxic heavy metal ions with widespread contamination in nature. Due to its severe toxicity, it has become a serious threat to human health and environment as well. Over the past years, various conventional techniques have been reported for detecting Hg(II) ion. These techniques are expensive and time consuming. The challenge is to develop novel methods for detecting Hg(II) ion, which are more efficient and cost effective. In the recent years, researchers have focused on developing nanomaterial-based ion sensors. These materials have proved to be efficient alternative in the speciation and detection of Hg(II) ion. This review sheds light on the two important nanomaterial-based sensors for Hg(II) ion: Fluorescent sensors and Colorimetric sensors. Such sensors involve pristine and functionalized nanomaterials like gold nanoparticles (NPs), Fe₃O₄ NPs, carbon dots, quantum dots, etc.