Carbon dots-embedded zinc-based metal-organic framework as a dual-emitting platform for metal cation detection

Carbon dots (CDs) was synthesized by hydrothermal method using o-phenylenediamine. The fluorescence property can be used for metal ion sensing, but the solid-state aggregation caused quenching (ACQ) is the troublesome problem to develop the potential applications of carbon dots. Here, the metal-organic framework (MOF) as a host is not only used for restraining the ACQ effect of CDs but also can be constructed by the dual-emitting system (CDs@ZIF-8). Furthermore, CDs@ZIF-8 with dual-emitting centers can be utilized for detecting copper ions as a ratio fluorescence sensor. The CDs@ZIF-8 fluorescence sensor shows excellent sensitivity, selectivity and strong environmental suitability for sensing Cu2+ ion with the limit of detection (LOD) for Cu2+ ion is 11.712 mu M. The CDs@ZIF-8 fluorescent probe was successfully applied to detect Cu2+ ions in an aqueous solution. CDs@ZIF-8 shows a new possibility to fabricate fluorescent molecular probes for the determination of heavy metal ions, which is taken on anti-inference in pH, anion and other influence factors.