Fluorescent carbonaceous materials isolated from cigarette ashes for the determination of iron(iii) in water samples

In the present work, ready-to-use fluorescent carbonaceous materials (CMs) were isolated from cigarette ashes by following a simple procedure based on the dispersion of ashes in water and subsequent filtration. The isolated raw material was characterized by fluorescence microscopy, Fourier transform infrared (FT-IR) spectroscopy, and dynamic light scattering (DLS) analysis. The isolated CMs displayed excitation-dependent fluorescence emission, which enables them to be used as a fluorescent probe. The developed fluorescent probe possesses high potential for sensitive and selective detection of Fe(iii) via a quenching mechanism. The decrease in fluorescence intensity was in linear relationship with the concentrations of Fe(iii) within the range of 0-89.6 μM. The fluorescent probe was successfully applied to the determination of Fe(iii) in tap and well waters with an average recovery of 87% with an excellent relative standard deviation (RSD) of 0.63%, regardless of the water sample analyzed. Besides, fluorescence variation in the presence of Fe(iii) was evaluated by analyzing red, green, and blue (RGB) channels of the fluorescence colors. Finally, the possibility of semi-quantitative determination of Fe(iii) in water by the naked eye using the proposed fluorescent probe was also evaluated.