Honeycomb-shaped vertically aligned carbon nanotubes decorated with molybdenum trioxide as an electrochemical sensor for glucose

In this study, an electrode based on transition metal oxide molybdenum trioxide (MoO3) was fabricated and applied to electrochemical biosensing for glucose. In the process of making electrodes with relatively larger specific surface areas, an array of carbon nanotubes (CNTs) was deposited on a silicon substrate, and then, MoO3 was coated on the array of CNTs by chemical vapor deposition to produce a MoO3/CNTs/Si structure of three-dimensional electrochemical biosensing electrodes. Biosensing measurement was carried out in the concentration region from 20 μM to 7 mM of sodium hydroxide (NaOH). The highest sensitivity of 17.4 μA/μM cm2 was measured in the concentration range of 20–100 μM. The correlation coefficient of linear response (R2) was 0.9929, thus showing that MoO3/CNTs/Si is an excellent nonenzymatic glucose electrochemical sensor.