Examination of Carbon Paste Electrode/TiO2 Nanocomposite as Electrochemical Sensor for Detecting Profenofos Pesticide

This study reports the preparation and performance of a smart material—a carbon paste electrode combined with TiO₂ semiconductor (CPE/TiO₂) as electrochemical sensor for detecting profenofos—a toxic organophosphates group insecticide widely used in agriculture. Such techniques as real samples tests and electrochemical tests were used to investigate the following parameters: a scan rate, an electrode response, a limit of detection (LoD), and repeatability. Based on the obtained results, the best mass composition of TiO₂ combined with CPE was found to be in a ratio of 1 : 1 : 5, with an anodic peak current (I_pa) of 150 μA, an anodic peak potential (E_pa) of 0.87 V, and an optimal scan rate measurement of 0.5 V s^–1. The LoD based on a linearity curve with a value of 4.0 × 10^–5 μM was also observed, and a repeatability test against the working electrode was performed until the 30th day, using the Horwitz ratio of 0.16. A good electrochemical performance of the working electrode tested against a real sample showed the specifically detected profenofos with I_pa value of 7.0 × 10^–5 μM.