Amperometric detection of glucose and H2O2 using peroxide selective electrode based on carboxymethylcellulose/polypyrrole and Prussian Blue nanocomposite

Abstract

Carboxymethylcellulose (CMC), which is obtained from one of the most abundant biomass materials in the world, could have a major role in many practical applications thanks to its promising properties. In this work, electrochemical synthesis of polypyrrole (PPy) with simultaneous incorporation of CMC as dopant/plasticizing agent and Prussian Blue nanoparticles (PBNPs) as a peroxidase mimetic catalyst have been performed to design biocompatible sensor platform. CMC displays an effective mission in every stage of sensor platform formation. It increases the dispersibility of pyrrole (Py) in water with its template effect, and it enhances the conductivity of polypyrrole chains after electropolymerization by acting as a dopant and a plasticizer. Moreover, CMC in the composite structure increases the hydrophilicity of the sensor platform that may cause a significant improvement in the operational stability of the sensor. Such a 3D interwoven structure produced on the indium tin oxide electrode by a smart combination of materials used exhibited high-performance sensor responses to hydrogen peroxide (H2O2) and glucose. Sensor optimization resulted in a limit of detection (LOD) of 0.59 μM, a linear range from 5 to 470 μM and a sensitivity of 456.8 μA mM−1 cm-2 for H2O2 detection. When the same sensor platform used in glucose detection after GOx immobilization resulted in 5.23 μM LOD with a linear range from 20 and 1100 μM and a sensitivity of 456.8 μA mM−1 cm-2. Moreover, the interference of the most common interfering compounds would exist in real samples was also featured to set the ground for further sensor studies based on CMC, PPy, and PBNPs.