A Facile Dual-Emission Ratiometric Carbon-Dot Fluorescent Probe and Its Application in Portable Chemical Sensors and Water Quality Analysis

Graphical In this study, We designed a double-emitting carbon quantum dots (G-CDs) and established a ratiometric fluorescence sensor. The semi-quantitative and visual detection of Fe 3+ was achieved based on the fluorescence color change of the probe. The method can be applied to the accurate determination of Fe 3+ in real samples and exhibits good interference resistance, selectivity and reproducibility. Based on the dual signal of double-emitting carbon quantum dots (G-CDs), a ratiometric fluorescence sensor is established to realize the analysis and detection of Fe 3+ in real samples. When the excitation wavelength is 360 nm and 480 nm, the double emission fluorescence peaks are located at the wavelengths of 477 nm and 523 nm. The former is the fluorescence response signal, and the latter is the fluorescence background signal. The semi-quantitative analysis of Fe 3+ was achieved based on the linear relationship between the ratio F 477 /F 523 of the two signals and the Fe 3+ concentration. The linear range of this method is 0.015–120 μM, and the limit of detection (LOD, S/N=3) is 5 nM. Meanwhile, the naked-eye visual detection of Fe 3+ can be realized according to the fluorescence color of the probe. The probe exhibits excellent anti-interference, selectivity and repeatability, and this method can be applied to the detection of Fe 3+ in actual samples.