An unmediated hydrogen peroxide biosensor based on hemoglobin incorporated in a montmorillonite membrane

Abstract

Hemoglobin was incorporated in a montmorillonite membrane. Electrochemical and spectroscopic studies revealed that the electron transfer reactivity and peroxidase activity of the protein were both enhanced. Nevertheless, its structure was still maintained native-like in the membrane. An unmediated hydrogen peroxide biosensor was accordingly prepared. The calibration plot of this H₂O₂ sensor was linear in the range of 1.0 × 10⁻⁶–6.0 × 10⁻⁴ mol L⁻¹. The relative standard deviation was 3.1% for six successive determinations at a concentration of 1.0 × 10⁻⁴ mol L⁻¹. The detection limit was 6.0 × 10⁻⁷ mol L⁻¹. Possible interferences in real sample analyses are discussed.