Design and Fabrication of a High-Performance Sensor for Formaldehyde Detection Based on Graphene-TiO₂/Ag Electrode

Abstract: This research explores the heightened sensitivity of the electrochemical formaldehyde detection achieved by incorporating a modified graphene paste electrode with a titanium dioxide-silver (TiO₂/Ag) composite (GTA). The G-TiO₂ matrix was augmented with varying masses of silver modifiers, namely, 0.2, 0.4, 0.6, and 0.8 g, aiming to establish the most effective composition for formaldehyde detection. Characterization through scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed the material’s composition, revealing GTA electrode nanocomposites consisting of carbon, oxygen, titanium, and silver with the compositions of 77.05, 19.46, 2.39, and 1.11%, respectively. An electrochemical analysis was conducted to assess the efficacy of the developed electrode in a 1 M K₃[Fe(CN)₆] solution. Furthermore, a real sample testing was performed to evaluate the practical utility of the electrode gauging its efficiency through the calculation of percentage recovery before and after treatment. The GTA electrode with a 0.4 g Ag modifier exhibited the optimal performance, as evidenced by a Horwitz Ratio stability test result of 1.38% and a limit of detection of 0.0168 µg/L. This research highlights the promising potential of the GTA electrode for the precise and sensitive formaldehyde detection, particularly in processed food products.