Colorimetric and fluorescent Schiff base sensors for trace detection of pollutants and biologically significant cations: A review (2010–2021)

The colorimetric and fluorescent Schiff base sensors have proven to be powerful tools in the detection of metal ions due to their simplicity, low cost, rapid photophysical response, high sensitivity, low detection limit, and application to the environmental and medical fields. The core concepts involved in the design of such sensors are: (a) analyte separation; (b) isolation of a specific analyte from a mixture of analytes; (c) signal generation due to species complexing. It is because several of these metal ions (such as K+, Na+, Cu2+, Ni2+, Zn2+, Fe2+, Mg2+, Co2+, etc.) play a prominent role in biological, medicinal, and environmental fields. Hence, their sensing or detection has become one of the most challenging and vital research domains among many other domains. In the presented review article, we have reviewed the recent (2010–2021) development of colorimetric and fluorescent Schiff base sensors to detect pollutants and biologically significant cations. Also, a summary includes the significant points, such as the structure of reported sensor, IUPAC name of sensor, detection limit (LOD), association constant, binding stoichiometry, the mechanism of binding, instrumental techniques used, and the practical applications. Lastly, we have talked about the a performance evaluation (pie chart), a conclusion and outlooks of Schiff base sensors for metal ion detection.