Integration of Prussian blue and carbon black onto a ceramic transducer nanocomposite: Development of a renewable Sonogel-Carbon electrochemical device for H2O2 sensing

A novel nanocomposite material for electrochemical sensing purposes has been developed in this work by the integration of redox mediator Prussian blue (PB) into a sonogel network. The synthesis of this organometallic complex has been carried out in presence of graphite and the nanomaterial carbon black (CB), achieving a superficial impregnation of these substrates. A ceramic transducer material has been assembled by combining the PB-containing nanocomposite and a green sonochemically synthesized silicon oxide matrix. This manufacturing process has been optimized by means of an experimental design to improve the analytical features of the sensor prepared on the detection of H2O2. A morphochemical characterization of the prepared materials have been carried out using STEM, EDS, FTIR, XRD and XRF. The novel Sonogel-Carbon/CarbonBlack-PrussianBlue (SNG-C/CB-PB) sensor device exhibited significant sensitivity (∼0.97 mA mM cm−2) in the determination of H2O2 over the range 0.1–2 mM, micromolar limit of detection (34 μM) and good reproducibility (RSD% = 3.8, n = 3). Several additional analytical features of the manufactured smart sensors, such as linear response up to 35 mM H2O2, renewability of the sensing platform via fast mechanical polishing, significant response at different pH values, signal stability over long periods or selectivity versus food interferents are also remarked. Milk samples enriched with H2O2 have been analyzed with the PB-based amperometric device, achieving good accuracy (recovery values between 95 and 103%) and reproducibility (RSD% = 4.4, n = 3). The most appealing aspect of the reported manufacturing methodology is the in-series assembling of eco-friendly, affordable and reusable nanozymes-containing electrodes without requiring further modifications.