Key Words:CARBON-PASTE ELECTRODE; IONIC LIQUIDS; NITRITE; HEMOGLOBIN; NANOPARTICLES; COMPOSITE; OXIDE; FILMS; REDUCTION; ZNO

Abstract:In this paper direct electrochemistry and electrocatalysis of myoglobin (Mb) immobilized on a graphene (GR)-SnO2 nanocomposite modified carbon ionic liquid electrode was reported. GR-SnO2 nanocomposite was synthesized by a simple solution method and further characterized by TEM and SEM, which exhibited large surface area beneficial for Mb immobilization. Spectroscopic results indicated Mb retained its native structure without denaturation after mixed with nanocomposite. Electrochemical investigation showed that a pair of well-defined redox peaks appeared on cyclic voltammogram, indicating that direct electron transfer of Mb with the underlying electrode was realized. The results could be attributed to the presence of GR-SnO2 nanocomposite that could enhance the electron transfer between the protein and the electrode. The Mb modified electrode exhibited good stability and catalytic activity to the electroreduction of NaNO2 in the concentration range from 0.2 to 350.0 mu mol L-1 with wider dynamic range and lower detection limit. Therefore the fabricated electrode has the potential application in the third-generation electrochemical biosensor. (C) 2015 The Authors. Published by Elsevier B.V. on behalf of King Saud University.

Volume:12

Issue:8

Translation or Not:no