The low-symmetry mesoporous titanium dioxide (lsm-TiO2) for use in an electrode for direct sensing of hydroxide ions may be prepared by evaporation-induced self-assembly followed by two stages of annealing. An electrode made of a conductive substrate coated with the lsm-TiO2 detects electrochemical oxidation of hydroxide ion solution by an oxidation peak for hydroxide ions at a lower potential than other metal electrodes. The oxidation process is irreversible under diffusion-control, the peak current linearly increases with hydroxide concentration within the concentration range from 1.0 to 50 mM, the detection limit may be 0.05 mM and the current sensitivity may be 0.181 mA/mM. The peak current is linearly dependent on alkaline solution pH and the dissociation constant of the hydroxide ion precursor. The electrode can be used in hydroxide sensing performed in nitrate, fluoride, chloride or sulfate supporting electrolyte, which makes the electrode a superior sensor for voltammetric hydroxide determination.