An unmediated hydrogen peroxide biosensor based on hemoglobin incorporatedin a montmorillonite membrane

Hemoglobin was incorporated in a montmorillonite membrane. Electrochemical and spectroscopic studies revealed that the electron transfer reactivity an d peroxidase activity of the protein were both enhanced. Nevertheless, its structure was still maintained native-like in the membrane. An unmediated h ydrogen peroxide biosensor was accordingly prepared. The calibration plot o f this H2O2 sensor was linear in the range of 1.0 x 10(-6)-6.0 x 10(-4) mol L-1. The relative standard deviation was 3.1% for six successive determina tions at a concentration of 1.0 x 10(-4) mol L-1. The detection limit was 6 .0 x 10(-7) mol L-1. Possible interferences in real sample analyses are dis cussed.