Zn-Doped TiO<sub>2</sub> Powder Prepared by Solution Combustion Synthesis as Non-Enzymatic Sensor for Acetylcholine Detection

Acetylcholine (ACh) is a main neurotransmitter functioning in smooth muscle and cardiovascular system control. It also plays a key role in memory and learning. While excessive acetylcholine level results in decreased heart rates, depleted level of acetylcholine in human brains can lead to Alzheimer disease. Therefore, detection of acetylcholine is clinically vital. This study aimed at examining potential usage of titanium dioxide (TiO2) doped with 2.5 mol% Zn as electrochemical sensors for acetylcholine detection. Zn-doped TiO2 powder was synthesized by a solution combustion technique. Phase identification, microstructural examination, as well as electrocatalytic activity evaluation of the synthesized powder were conducted. The synthesized powder showed anatase phase with fine particle sizes ranging from 9.3 to 11.4 nanometers on average. Specific surface area of 75.48 m2/g was observed. Electrocatalytic activities of the powder in cholin acetate solutions with concentrations ranging from 0.05 to 0.1 μM and 1 to 10 μM were evaluated via cyclic voltammetry technique. At applied voltage of 0.05 V, peak currents corresponding to oxidation reactions between ACh and Zn-doped TiO2 were detected. Sensitivity values of 3.13x10-4 and 1.32 μA/(μMmm2), which is in an acceptable range, were evident.