A Very Strong Blue Fluorescent Probe for Hexavalent Chromium Detection with Highly Selective and Sensitive Performance

A wide variety of methods including chromatography, chemiluminescence and spectrophotometry have been reported to detect hexavalent chromium. Recently, carbon quantum dots (CQDs) have gained increasing attention as effective probes for inorganic ions, organic molecules, and biomolecules. However, there are still some bottlenecks, such as raw materials being too expensive to obtain, the materials have a low quantum yield (QY), and the preparation process is not environmentally friendly. Here, we prepare a very strong fluorescent probe through a simple, rapid, and green one-pot hydrothermal method with blue emission (QY, 61.1%). The obtained CQDs exhibit good water solubility, low toxicity, and photostability. Moreover, the CQDs show good selectivity and sensitivity to hexavalent chromium (Cr(VI)) under neutral conditions, with a linear range of 1–100 μM and a detection limit of 0.19 μM. Meanwhile, this fluorescent probe has been successfully applied for the highly selective analysis of Cr(VI) in natural water samples, which demonstrated its potential in environmental field applications.