Catalytic activity of Schiff base monocrystal and its application for colorimetric detection of dopamine

In this work, we used 2-amino-4-methylphenol and terephthalaldehyde as reactants to synthesize a new type of Schiff base crystal (MAPTPA). It is yellow with an empirical formula of C 22 H 20 N 2 O 2 . The synthesized MAPTPA exhibits an intrinsic visible light-induced oxidase-like catalytic activity without the use of destructive H 2 O 2 . The results show that dissolved oxygen plays an important role in the catalytic reaction process and 1 O 2 is the crucial reactive species responsible for TMB oxidation. The results of Michaelis–Menten kinetics demonstrate that MAPTPA has high substrate affinity and catalytic efficiency. Based on the catalytic activity of MAPTPA, we developed a sensitive visual sensing strategy for dopamine (DA) detection. A high linear relationship is observed in the range of 0.01–100 μM with a detection limit (LOD) of 6.70 nM. Therefore, the as-prepared Schiff base monocrystal may be used as an oxidase mimic for life sciences in the future, such as biosensor, biosynthesis, photodynamic therapy, etc.