Polyaniline/multiwall carbon nanotubes/starch nanocomposite material and hemoglobin modified carbon paste electrode for hydrogen peroxide and glucose biosensing.

This paper describes the application of novel nanocomposite material polyaniline/multiwall carbon nanotubes/starch (designated as PCS) as a good electrode material for electrochemical sensing. The developed ternary composite system has manifold interactions and synergistic improved properties - high surface area, good electro-activity, conductivity, stable dispersion, biocompatible, hydrophilic and hydrophobic regions, multifunctional, and nanoturmeric shape morphology. Hydrogen peroxide biosensor was fabricated as a model system using PCS and hemoglobin (HB) modified carbon paste electrode. PCS and HB compatible and effectively communicate with each other, facilitate the charge transfer (potassium ferricyanide used as electroactive marker). Thus, PCS and HB (in combination) is a good electrode material for sensitive and selective detection of peroxide. The developed biosensor showed a linear range (0.1 mM-5 mM, R2 = 0.9975), limit of detection (0.032 mM), sensitivity (76.43 μA/mM cm2) and long-term storage and stability. This material could be used a platform to develop some other sensors by using other redox enzymes. As a model, we incorporate glucose oxidase to detect Glucose. Thus, the favorable properties indicate that the proposed material system suitable for low-cost sensor strips.