Pyruvate Oxidase Biosensors Based on Glassy Carbon Electrodes Modified with Carbon Nanotubes and Poly(Neutral Red) Synthesized in Ethaline Deep Eutectic Solvent
Ricardo J.B. Leote, Mariana Emilia Ghica, Christopher M. A. Brett
Abstract
Abstract A novel nanostructured platform for pyruvate oxidase biosensors comprises poly(neutral red) (PNR) prepared by electropolymerization of NR in ethaline deep eutectic solvent (DES) with acid dopant, on a multiwalled carbon nanotubes (MWCNT) modified glassy carbon electrode (GCE). Characterization was by cyclic voltammetry and electrochemical impedance spectroscopy and morphology was examined by scanning electron microscopy. Ascorbate and H 2 O 2 gave a better response at PNR DES /GCE than at PNR aq /GCE. Biosensors for pyruvate and phosphate, immobilizing pyruvate oxidase onto PNR DES /MWCNT/GCE enabled selective determination of pyruvate and phosphate, with micromolar limits of detection. Pyruvate was determined in onion samples and phosphate in water samples.