Design Strategies and Analytical Performance of Dansyl Fluorophore-Based Fluorescent Sensors for Mercury Ion (Hg 2+ ) Detection in Water

Recent years have seen a growing focus on the sensing of heavy metal cations in environmental samples, as we seek to promote a more sustainable environment. Mercury ion (Hg2+) is a heavy metal cation that has received significant attention in recent years due to its toxic nature to the ecology system. Exploring an efficient testing device to trace the content of Hg2+ is of great importance. Dansyl chloride (DNS-Cl)-based sensors, with their unique recognition unit, have emerged as highly effective optical chemosensors for the sensing of Hg2+. These probes produce a fluorescent change in the either visible or ultraviolet range, as well as in an electronic and fluorometric spectrum, serving as a detection signal. These sensors are inexpensive, robust, eco-friendly, sensitive, and selective to Hg2+, making them a focus of attention for analytical and environmental laboratories. This review explores the applications of DNS-Cl derivatives in optical sensing for the detection of Hg2+, emphasizing the potential of sensors based on DNS-Cl in the sensing of Hg2+. The review assesses the advancements achieved in the field of fluorescent sensors utilizing DNS-Cl as a recognition unit. Notably, it underscores that the majority of these fluorophores have exhibited a high level of effectiveness in detection of Hg2+.