A novel approach has been developed for a highly sensitive, fast responding and stable monoenzymatic amperometric biosensor for the detection of hydrogen peroxide using coimmobilized the single walled carbon nanotube (SWNT) and methylene blue (MB) into the metal oxide (SnO2) derived organically modified sol-gel glasses (ormosil). Nafion (NAF) was dispersed within the ormosil matrix to enhance the electron transportation in the modified film. Horseradish peroxidase (HRP) was diffusionally adsorbed onto the SWNT/ormosil modified ITO (Indium tin oxide) electrode surface. The SWNT/ormosil-modified electrodes were characterized with scanning electron microscopy (SEM), Atomic Force microscopy (AFM) and UV-vis spectroscopy. Cyclic voltammetry and amperometry measurements were used to study and optimize the performance of the resulting peroxide biosensor. The apparent Michaelis-Menten constant was determined to be 1.6mM. The effect of pH, SWNT content, applied potential and temperature on the peroxide biosensor has been systemically studied. The fabricated biosensor had a fast response of H2O2, less than 5s and excellent linear range of concentration from 5x10-7 to 1x10-4M with the detection limit of 0.3μM (S/N=3) under the optimum conditions. These results show that this amperometric biosensor could be used for the measurement of H2O2 in cellular, enzyme systems or cancer cell studies without the help of any fluorescent probes or detection reagents.