Recent developments in Schiff base centered optical and chemical sensors for metal ion recognition

The constant release of heavy metal ions into the environment has posed a serious threat to the environment as well as organisms. It became necessary to monitor their limits in water bodies and detect their presence in very minute quantities. There are various techniques to do this job, but most of these techniques are time-consuming, complex, and costly. Schiff base sensors are employed for this purpose, as this method is easy and quick-responsive in nature. There are various spectroscopic changes after the chelation of the Schiff base sensor with a particular metal ion. Since their discovery by Hugo Schiff in 1864, Schiff bases have been used in various applications, like turn-on/turn-off sensors for the detection of heavy metal ions and non-metal ions in water bodies and biological mediums. Schiff base offers a great way to detect hazardous ions or provide their presence in the surrounding atmosphere. This review article covers a wide range of metal ion detection by Schiff bases and their mechanisms of detection.