A fluorescent photochromic oxazine derivative as a cyanide ion probe for aqueous solutions and food samples†

A fluorescent photochromic oxazine derivative was prepared, and its structure was established using spectroscopic techniques including FT-IR, NMR, and HR-MS. Upon evaluation, the probe detected the presence of cyanide ions in aqueous solution. Specifically, the photochromic oxazine-based probe exhibited a color change from colorless to yellow in the presence of cyanide ions in an aqueous solution. The probe was also used as a smartphone-based probe for the detection of cyanide ions with an limits of detection (LOD) value of 0.97 μM. UV-vis and fluorescence spectroscopic analysis provided LOD values of 0.87 μM and 1.26 μM, respectively. NMR and HR-MS were also used to confirm the formation of a complex between the probe and cyanide ion. Furthermore, PW6B95/6-31+G(d,p) and CAM-B3LYP/6-31+G(d,p) methods were used to correlate the experimental results with the computationally calculated data to understand the complex formation. The probe was also used to estimate the concentration of cyanide ions in a food sample.