A simple and sensitive Ce(OH)CO3/H2O2/TMB reaction system for colorimetric determination of H2O2 and glucose

The detection for H2O2 is essential in many areas, including life activity, medical diagnosis, industry and agriculture production and environmental monitoring, etc. This work developed a simple and sensitive two-step reaction system Ce(OH)CO3/H2O2/TMB for H2O2 determination. Upon sequential addition of H2O2 and TMB to Ce(OH)CO3 powders, a typical color reaction occurred quickly, producing a characteristic blue color in a slightly acidic aqueous solution. The underlying reaction mechanism was proposed based on the color reaction catalyzed by mimetic enzyme. The dependence of the color depth on H2O2 concentration enabled the colorimetric determination of H2O2. This reaction system responds linearly and quickly in a wide H2O2 concentration range of 0-80 μM, and achieves a detection limit of 0.3 μM H2O2 and a relative standard deviation lower than 5.1%. This H2O2 sensing system was modified to allow for the detection of glucose since H2O2 is one of the main products in the oxidation reaction of glucose catalyzed by oxidase enzymes. In addition to a wide linear response, a low detection limit and a high reproducibility, our present reaction system for glucose determination showed a highly specific response to glucose due to the specificity of glucose oxidase to glucose.