Integrating carbon dots to advance measuring aquatic metal ion pollutants: sensing and computational modeling

• Discuss various synthetic approaches for CQDs. • Presents insights into sensitive and selective CQD-based sensors for the detection of inorganic pollutants in water bodies. • Integrates computational modeling data with experimental insights to explain and predict metal ion sensing mechanisms. • Emphasis on the effect of the dopants and the surface functionalization on the fluorescence response towards metal ions. Detecting metal ion pollutants at low concentrations requires high sensitivity and selectivity, posing a significant challenge. Carbon dots have emerged as a successful substrate, demonstrating their efficacy in sensing a wide range of metal ions, including iron, mercury, cadmium, aluminum, lead, and many others. Carbon dots that are functionalized with oxygen ligands, including hydroxyl and carboxylic acid, exhibit distinct sensitivity to metal ion pollutants. Furthermore, carbon dots doped with elements such as nitrogen, sulfur, and phosphorus have featured prominently in numerous studies focused on detecting metal ions. Theoretical studies have proven to be a valuable tool in understanding the sensing mechanism of CDs for metal ion pollutants. Through computational simulations and calculations, we reviewed the complex interactions between CDs and metal ions at the molecular level, revealing the underlying principles that control the sensitivity and selectivity of CDs towards specific metal ions. In this review, we examine the mechanisms, sensing, and computational modeling that underlie carbon dot metal ion sensing capabilities. These CD-based sensors will continue to make significant contributions to real life applications covering environmental, industrial, biomedical diagnostics, and therapeutics fields.