Highly efficient determination of Mn 2+ in Chinese liquor by using a novel electrochemical sensor based on TiO 2 -NH 2 @covalent organic framework nanocomposites.

This study developed an electrochemical sensor for the determination of Mn 2+ in Chinese liquor by modifying a glass carbon electrode with TiO 2 -NH 2 @COF DPTB , which was synthesized via the controllable growth of COF DPTB onto the surface of TiO 2 -NH 2 using the Schiff-base condensation reaction between 2,5-dimethoxyterephthalaldehyde and 1,3,5-tris(4-aminophenyl)benzene. The morphological and structural characterization studies of the proposed TiO 2 -NH 2 @COF DPTB were carried out by SEM, TEM, HRTEM, EDX, BET, XRD and FTIR techniques. Owing to the excellent properties and the synergism between TiO 2 and COF DPTB , the introduction of TiO 2 -NH 2 @COF DPTB improved the electrochemical response significantly. By optimizing the experimental parameters, the sensor exhibited good linearity in the range of 0.1-1.0 nM and 0.08-10 μM with a detection limit of 2.83 × 10 -11 M and 9.50 × 10 -9 M, respectively, showing competitive performance for Mn 2+ determination. Besides, the proposed sensor was successfully applied to Mn 2+ detection in liquor samples, suggesting its practical application performance.