Synthesis, characterization of vanillin based colorimetric chemosensor for sensing of fluoride ions

•Synthesis, characterization of novel VSB colorimetric chemo sensor.•Selective sensing of fluoride ion and detection limit found to be 6.1 × 10−6M − 1.•Trifluoroacetic acid as protonating agent for reproduction of deprotonated VSB. A novel colorimetric chemosensor (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)-2-methoxyphenol (VSB) was prepared, characterized using FT-IR, NMR, Mass spectrometry, UV-Visible spectroscopy and elemental analysis. VSB is documented as a colorimetric and radiometric chemosensor for particular detection of fluoride ions with the detection limit 6.1 × 10−6. The sensing mechanism of F− ion as a result of total deprotonation of OH and NH protons from VSB which is studied by UV–visible and 1H NMR titration examinations. The 1H NMR titration investigation was established the deprotonation of OH and NH protons by F− as a strong indication for fluoride ion detection. In addition, deprotonated VSB can be subjected to protonation using 0.001 M of trifluoroacetic acid as a protonating group. [Display omitted] Novel colorimetric chemosensor VSB were synthesized and sensing with fluoride ion, and detection limit 61 nm.