An Ultrahigh Selective and Sensitive Enzyme-Free Hydrogen Peroxide Sensor Based on Palladium Nanoparticles and Nafion-Modified Electrode

An ultrahigh selective and sensitive hydrogen peroxide electrochemical sensor was developed based on palladium nanoparticles and nafion-modified electrode in enzyme-free conditions. The surface morphology of the fabricated electrode was characterized by using field emission scanning electron microscopy and electrochemical impedance spectroscopy. The fabricated sensor displayed an excellent electrocatalytic reduction of hydrogen peroxide (H₂O₂) at −0.2 V. The as-prepared-modified electrode displayed a very fast amperometric response (<2 s) of H₂O₂, indicating excellent electrocatalytic performance of the modified electrode. The sensor showed wide linear range response from 0.1 μM to 9 mM with a limit of detection of 0.018 μM for the determination of H₂O₂. In addition, the sensor displayed a high sensitivity of 0.766 μA μM⁻¹ cm⁻² with acceptable repeatability, reproducibility, and stability. The developed H₂O₂ sensor is highly selective even in the presence of higher concentrations of the potentially interfering species. The good practicality of the sensor indicates that it could be used as a good potential candidate for the real-time sensing of H₂O₂.

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