Preparation and characterisation of dual sensing carbon dots for water and Cu 2+ detection

In this work, hydroquinone, o -phenylenediamine and terephthalic acid were used as reaction precursors to synthesize carbon dots (h-CDs) by a one-step solvothermal method. Our experimental results demonstrated the as-prepared functionalized h-CDs have not only excellent optical properties but also interestingly chemical and physical properties. The emission peak of the obtained h-CDs shifts gradually towards the red region with increasing water content in organic solvent. This was visually manifest as a change in color. Therefore, the h-CDs can be used as the colorimetric fluorescent probe to detect water content in organic solvents. Moreover, it is also particularly sensitive to Cu 2+ and thus could be used as fluorescent probe to detect Cu 2+ content in water with detection limit of 1.8 × 10 −4  mmol. This investigation provides a new way for the development of carbon dots (CDs) as multifunctional fluorescent probes.