An inorganic base stripping approach to synthesize N-doped Ti3C2 quantum dots as fluorescence nanoprobe for the simultaneous detection of Co2+ and Ag+ ions

N-doped Ti3C2 quantum dots (N-Ti3C2 QDs) as the fluorescent nanoprobe were synthesized through inorganic base (i.e. KOH) stripping and solvothermal approach. The N-Ti3C2 QDs displayed well-monodispersed nearspherical particles with average size of 2.3 nm, exhibited brightly blue emission and good stability, and possessed 14.46% of fluorescent quantum yield. Upon addition of Co2+ or Ag+ ions, the fluorescence (FL) of N-Ti3C2 QDs could be quenched significantly. Mechanism investigation indicated that the inner filter and static extinguishing effects are responsible for the Co2+ or Ag+ ions induced FL quenching of the N-Ti3C2 QDs. Based on above outcomes, we developed a simple N-Ti3C2 QDs based fluorescent assay for the simultaneous determination of Co2+ and Ag+ ions, with a low detection limit of 0.21 and 0.10 mu M, respectively. The assay was used to determine the content of Co2+ and Ag+ in real samples. This work will provide another way for the synthesis of fluorescent N-Ti3C2 QDs and exploited their application in simultaneous detection of Co2+ and Ag+.