Prussian Blue modified boron-doped diamond interfaces for advanced H2O2 electrochemical sensors

We report on the boron-doped diamond (BDD) electrodes modified with Prussian Blue (PB) through electrochemical synthesis, open-circuit deposition, and immobilization of Prussian Blue based nanozymes. The later allowed attaining the utmost sensitivity of the H2O2 sensor (≈0.14 A M−1 cm−2). Compared to conventional graphite electrodes modified with Prussian Blue, the use of BDD provided twenty times decreased oxygen reduction currents resulting in up to ten times increased signal-to-background ratio of the corresponding modified electrodes. The successful combination of exceptional diamond properties (including wide potential window for BDD electrodes) with advantageous performance characteristics of Prussian Blue sensing layers would open new horizons for H2O2 detection as well as biosensors elaboration. •Electron transfer rate at the H-terminated B-doped diamond electrodes is sufficient.•Prussian Blue nanozymes immobilization provides the utmost sensitivity towards H2O2.•O2 reduction currents at the doped diamond.|Prussian Blue sensors are 20 times lower