Luminescent CePO₄:Tb colloids for H₂O₂ and glucose sensing

Hydrogen peroxide (H2O2) is an essential molecule in intracellular signaling transduction and normal cell functions. It is critical to be able to detect H2O2 quantitatively in cellular processes for getting useful physiological information. Herein, we developed a novel fluorescent probe for H2O2 sensing, CePO4:Tb colloidal solution. Upon addition of H2O2, the luminescence of the colloidal CePO4:Tb solution responds linearly in a wide H2O2 concentration range of 0-200 μM, allowing for quantitative detection of H2O2. The H2O2 sensing by this method exhibits a rapid response within several minutes, a detection limit of 1.03 μM H2O2, and a relative standard deviation lower than 3.1%. This sensing material for H2O2 is also suitable for the detection of glucose since H2O2 is generated via the catalytic oxidation of glucose by oxidase enzymes. In addition to a wide linear response, a low detection limit and a high reproducibility, our present method for glucose sensing shows a highly specific response to glucose in a mixed carbohydrate solution due to the specificity of glucose oxidase to glucose. This lanthanide-based fluorescent sensing material might have potential for detecting H2O2 and glucose in biological applications.