Ratiometric fluorescent probe based on dual-emissive carbon dots for determination of silver ions

In this work, a one-step solvothermal method using O-phenylenediamine and DL-malic acid was used to obtain blue/yellow-emitting carbon dots (B/Y-CDs). The B/Y-CDs have two independent fluorescence emission peaks centered at 453 nm and 584 nm at a single excitation wavelength. In the presence of silver ions (Ag+), the fluorescence at 453 nm was quenched and the fluorescence at 584 nm was enhanced by dynamic quenching and redox reaction mechanisms, respectively. The "Double-Response-Reverse" ratiometric fluorescent probes constructed on the basis of the B/Y-CDs showed a good linear relationship with Ag+ in the range of 1-90 μM. In addition, the feasibility of this detection strategy for the detection of Ag+ in real water samples was verified, and the probe showed satisfactory recoveries, which could be applied to the quantitative analysis of Ag+ in real environmental water samples. This work provided a new strategy for the identification and detection of Ag+, enriching the ways of detecting Ag+.