A simple, low cost sensor was developed for the voltammetric determination of hydrogen peroxide in mouthwash and dental whitening gel based on multi-walled carbon nanotubes incorporated with hemin. The sensor showed electrocatalytic activity toward the reduction of hydrogen peroxide in 0.05 mol L-1 Tris-HCl buffer solution (pH 7.0) using cyclic voltammetry. The optimum composition of paste was 20:10:70% (m/m/m) (multi-walled carbon nanotubes:hemin:mineral oil). A linear plot of the square root of scan rate vs. cathodic peak current showed that reduction of hydrogen peroxide is diffusion controlled. Using linear sweep voltammetry, the analytical curve ranged from 0.2 up to 1.4 mmol L-1 (r = 0.9996) with a sensitivity of 3.62 × 10-2 mA mol-1 L. The limits of detection and quantification were found to be 12.5 μmol L-1 and 41.7 μmol L-1, respectively. The developed method was applied for hydrogen peroxide determination in dental formulations. 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