Amperometric sensor for gaseous H2O2 based on copper redox mediator incorporated electrolyte

The determination of gases and other volatile compounds using electrochemical gas sensors remains a challenge with respect to sensitivity and selectivity. Many real-life situations require fast, sensitive, and yet easy-to-operate sensors for gaseous hydrogen peroxide (H₂O₂) that can operate at room temperature. Herein, we present an H₂O₂ gas sensor comprising a polyacrylic acid and NaOH gel electrolyte that included Cu(II) ions acting as a redox mediator and commercially available screen-printed carbon electrodes. Aqueous polyacrylate gel electrolyte containing Cu(II) provided for sensing material that enabled the accumulation and stabilization of the gaseous analyte and via redox interaction with Cu(II) its fast and sensitive detection. The designed sensor exhibited good sensitivity in the low mg m⁻³ range with a wide linear response in the examined concentration range of 10–100 mg m⁻³ and a rapid detection after only 2 min accumulation under ambient conditions. Sensor's relatively simple setup and solid electroanalytical performance have strong application potential in emerging fields such as clinical diagnostics, explosive detection, environmental monitoring and occupational health and safety.