Prussian Blue bulk modified screen-printed electrodes for H2O2 detection and for biosensors

A sensor for H2O2 amperometric detection based on a Prussian Blue (PB) bulk modified carbon screen-printed electrode was developed. It has been optimised with respect to the lowest limit of detection achieved. PB was made chemically by the reaction of FeCl3 with K4[Fe(CN)6]. The resulting powder, obtained by forced crystallisation induced by acetone, was dried and activated at 150 °C for 10 h. PB microparticles (<38 μm) were prepared and mixed with carbon ink. The limit of detection achieved was 0.4 μM with the linear range up to 100 μM of H2O2 with the sensitivity of 137 μA mM−1 cm−2, that was comparable with sensors based on electrodeposited PB film. The transducer was applied for a glucose biosensor, that exhibited LOD of 0.22 mM, linear range up to 3 mM, KMapp of 4.6 mM, and the sensitivity of 3.21±0.16 μA mM−1 cm−2. The peroxide sensor, as well as the glucose biosensor, were totally insensitive to oxygen, ascorbate, urate, and paracetamol.