CV Determination of Hydrogen Peroxide Using a Biosensor of Horseradish Peroxidase/Multi-walled Carbon Nanotube Modified Platinum Electrode

One mg of multi-walled carbon nanotube (MWCNT′s) was dispersed in 5 mL of 0.5 g·L-1 chitosan and dropped onto the surface of Pt electrode. The MWCNT′s modified Pt electrode prepared as described above was immersed in horseradish peroxidase (HRP) solution for 8 h, and the HRP was adsorbed electrostatically on the surface of MWCNT′s modified electrode. Thus the hydrogen peroxide biosensor was prepared and ready for use in determination of hydrogen peroxide. It was found that in a phosphate buffer solution of pH 6.0, the reduction of hydrogen peroxide at the modified electrode was remarkably catalyzed. Cyclic voltammetric determination of hydrogen peroxide was performed in the linearity range of 3.5×10-5 to 9.0×10-3mol·L-1 in respective to the value of reductive peak current. Value of detection limit (3S/N) found was 2.4×10-5mol·L-1. Test for recovery was made by standard addition method, and values of recovery found were in the range of 96.0%-101.8%.