TiO2/CeO2-CePO4-decorated enzymatic glucose biosensors operating in oxygen-restrictive environments

The detection of glucose plays an important role in monitoring and controlling diabetes as well as its complications caused by high blood glucose levels. There have been a lot of research on glucose sensors and integrated flexible sensing platforms; however, the detection in oxygen-restrictive environments is few reported. Herein, we described the use of a novel system made up of TiO2 and ceria-cerium phosphate (CeO2-CePO4) composite nanostructures synthesized by a simple procedure to address the oxygen dependence problem confronted in the first-generation amperometric glucose biosensors. The enzymatic activity of sensors was tested in both oxygen-rich and restrictive environments. Our results showed that the resulting composites present good electro-catalytic activity towards glucose oxidation. The electrodes decorated by TiO2/CeO2-CePO4 showed a wide linear range from 0.1 to 1.7 mM with a low detection limit of 17.1 mu M while the CeO2-CePO4 showed the linear range of 0.1-2.5 mM with limit of detection of 58.0 mu M in oxygen-rich environment. Two types of decorated electrodes both responded to glucose well under the oxygen-restrictive environment but former showed better response performance. The as-fabricated electrodes also owned the good anti-interference, stability, and reproducibility. This strategy promises for increasing the sensitivity of glucose biosensors and provides more opportunities for operation in oxygen-restrictive conditions.

Automated summary

The research described a novel system composed of TiO2 and CeO2-CePO4 composite nanostructures to address the oxygen dependence issue in the first-generation amperometric glucose biosensors. The resulting composites showed good electro-catalytic activity towards glucose oxidation and provided a wide linear range for glucose detection, promising increased sensitivity of glucose biosensors.