Basic Fuchsin Dye as the First Fluorophore for Optical Sensing of Morpholine in Fruits Crust and Urine Samples

In this work, basic fuchsin (BF) dyestuff was presented as the first optical sensor used for the spectrofluorimetric assessment of morpholine (MOR) where BF exhibits morpholine-sensing behavior. The developed fluorimetric avenue is sensitive, facile, selective, and validated for assaying the sensitizing influence of MOR on the BF fluorescence in an aprotic dioxane solvent. Parameters like solvents, BF concentration, order, and time of addition that influence the fluorescence intensity of the probing system were addressed. Optimizing the analytical methodology revealed a linear fluorescence sensitization within the addition of MOR in the two concentration ranges of 5 × 10^-9 to 1.0 × 10^-7 mol L^-1 and 2.0 × 10^-7 to 3 × 10^-6 mol L^-1. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 2.0 × 10^-9 mol L^-1 (0.17 ng mL^-1) and 6.66 × 10^-9 mol L^-1 (0.567 ng mL^-1), respectively. High levels of accuracy and precision are achieved when assaying spiked MOR either in pure solutions or samples of fruit peel extract and human urine. Moreover, the green character and practicality/applicability of the method were evaluated by AGREE and BAGI metric tools. These merit outcomes provide insights into the development of fluorescent sensors for MOR detection using fluorescent dyes and meet the Food and Drug Administration's requirements for morpholine detection in real-life applications.