Enzyme-free detection of hydrogen peroxide with a hybrid transducing system based on sodium carboxymethyl cellulose, poly(3,4-ethylenedioxythiophene) and prussian blue nanoparticles

Highlights: • Ni-HCF supported hybrid composite based on CMC, PEDOT and PBNPs designed for enzyme-free H₂O₂ sensing. • CMC assists the immobilization of PBNPs on ITO electrode through electrochemical polymerization of EDOT in water. • The improvement in potential cycling and amperometric operational stability of the sensor has been presented. • The sensitive H₂O₂ detection avoiding the interference of electroactive-ions could exist in tap water has been performed. Herein, we report a two-layered hybrid catalytic interface composed of carboxymethyl cellulose (CMC), poly (3,4-ethylene dioxythiophene) (PEDOT), Prussian blue (PB) nanoparticles and Nickel-Hexacyanoferrate (Ni-HCF) layer for the enzyme-free detection of hydrogen peroxide (H₂O₂). Whereas the first layer, CMC:PEDOT:PB, is responsible for generating amperometric signals toward H₂O₂, Ni-HCF on CMC:PEDOT:PB layer is playing an active role as an operational stability-enhancer. In the study, where the systematic optimization of the sensor electrode is presented using cyclic voltammetry (CV), amperometry and electrochemical impedance spectroscopy (EIS) technique, the physical and chemical properties of the hybrid composite systems constructed is also supported by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) techniques. The amperometric signal generation of the H₂O₂ sensor was linear between 1 and 100 μM (R² = 0.999) with a sensitivity of 416.11 μA mM⁻¹cm⁻², providing a limit of detection (LOD) of 0.33 μM. The sensing system, which was not affected by the various interfering molecules, creates a successful sensor platform for H₂O₂ measurements in tap water with a high recovery value between 94.0% and 110.5% and relatively small RSD in the range of 0.4–5.2%.