Cobalt(II) ions detection using carbon dots as an sensitive and selective fluorescent probe

A simple method was designed for detecting cobalt ions (Co2+) based on the analyte-induced fluorescence quenching of carbon dots (CDs). CDs with a quantum yield of 38.7% were synthesized by hydrothermal treatment of Carbopol 934 and diethylenetriamine. Through the metal-ligand interaction, the prepared CDs can allow highly sensitive and selective detection of Co2+. The color change (from transparent to brown) of the solution can be clearly seen with the naked eye. This effective sensing platform shows high sensitivity and selectivity towards Co2+. Moreover, the CDs are also successfully utilized for monitoring the Co2+ content of natural water.