Amperometric sensing of H₂O₂ and glucose using wet-chemically deposited MnO₂ thin films

Abstract

Herein, we report that δ-MnO₂ thin films wet-chemically deposited on electro-conductive substrates exhibited good sensing abilities toward hydrogen peroxide and glucose without the assistance of immobilized enzymes, as well as the excellent supercapacitic performance described in our previous paper. High-sensitivity values of 380 mA/(M·cm²) (H₂O₂) and 300 mA/(M·cm²) (glucose) were attained with low detection limits of 0.7 µmol/dm³ (H₂O₂) and 0.6 µmol/dm³ (glucose). The good sensitivities and low detection limits were attributed to the large surface area of accumulated MnO₂ nanosheets and their firm adhesion to the substrates. The method presented herein can be used for facile film deposition with good controllability and reproducibility.