A series of test samples were prepared with different anions that include F−, Cl−, Br−, I−, NO3−, View the MathML sourceSO42− and CH3 COO−. Each of the anion solutions were prepared in DI water and maintained at a specific concentration of 5 mg/L 40 μL of 4% TBDPSC solution prepared in THF was then added to 1 mL of each of these solutions. Fluorescence spectra was obtained for each of these solutions with corresponding excitation and emission wavelengths of 360 nm and 450 nm, respectively.