Aggregation-induced emission enhancement of yellow photoluminescent carbon dots for highly selective detection of environmental and intracellular copper (II) ions

Abstract Carbon dots (CDs) are prepared through a simple one-step hydrothermal treatment of o -phenylendiamine (OPD) and show yellow photoluminescent (PL) emission under the ultraviolet excitation, which can be further enhanced by Cu 2+ ions owing to Cu 2+ ions induced aggregation of OPD-CDs through the coordination of Cu 2+ with amino groups on the surface of OPD-CDs. The aggregation induced emission enhancement (AIEE) property enables it feasible to develop a simple, sensitive and selective method to detect environmental and intracellular copper (II) ions. The limit of detection as low as 0.28 μmol/L (3 σ / k ) and a dynamic range from 0.5 μmol/L to 40 μmol/L make it very easy to detect the copper content in water samples, such as river closure reservoir. Furthermore, fluorescence imaging of intracellular Cu 2+ suggests that the AIEE features of OPD-CDs specific to Cu 2+ ions can be also applied in biological systems.