Abstract

Detection of fluoride ions in various solvent media and pH has been successfully carried out using UiO-66-NH₂ as the fluorescent probe. UiO-66-NH₂ was synthesized via the hydrothermal method using various modulators such as Acetic Acid (AA) Formic Acid (FA), Hydrogen Chloride (HCl), and Hydrogen Fluoride (HF). The success of the synthesis was proven by characterization using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Scanning Electron Microscope (SEM). The results showed that UiO-66-NH₂ synthesized using HF as a modulator provided higher %crystallinity values and fluorescence intensity at the maximum emission peak at 428 nm. In the detection of fluoride ions in various solvent media, it was seen that the water medium gave the highest fluorescence intensity compared to THF, ethanol, acetonitrile, DMSO, ethyl acetate, DMF, toluene, and acetone media. Varying pH detection (3–11) of fluoride ions did not give significantly different results, but pH 7 gave higher detection fluorescence intensity results. Overall it can be concluded that HF is a very suitable modulator in synthesizing UiO-66-NH₂. Detecting fluoride ions provides the best fluorescence intensity in water and pH 7. The Limit of Detection (LoD) value obtained is 0.036 ppm with a linear range of 0–10 ppm.