Photoelectroanalytical Sensor Based on TiO2 Nanoparticles/Copper Tetrasulfonated Phthalocyanine for Detection of Dopamine Exploiting Light Emitting Diode Irradiation

Abstract In this manuscript, a novel photoelectroanalytical sensor for detection of dopamine based on anatase TiO 2 nanoparticles sensitized with copper tetrasulfonated phthalocyanine (CuTsPc/TiO 2 ) was developed. The CuTsPc/TiO 2 photoelectroanalytical sensor shows high anodic photocurrent under visible light emitting diode irradiation in comparison to pure anatase TiO 2 nanoparticles. The CuTsPc/TiO 2 composite shows a photocurrent about 2.5‐fold higher than those of pure TiO 2 nanoparticles or CuTsPc modified electrode. The CuTsPc/TiO 2 composite shows a low charge transfer resistance in comparison to its individual components as well as the impedance circle radius decreases significantly under UV light illumination. Under optimized conditions, the photoelectroanalytical sensor shows a linear response range from 4 up to 810 µmol L −1 with a sensitivity of 3.0 nA L µmol −1 and limit of detection of 0.5 µmol L −1 for the detection of dopamine. The photoelectrochemical sensor shows high photocurrent to dopamine in comparison to foreign species such as ascorbic acid, uric acid, glucose, K + , Na + , and Cl − .