Enhancing the performance of a fluidic glucose biosensor with 3D electrodes

In this work, we enhanced the performance of a fluidic glucose sensor by using three dimensional electrodes made of standing nanopillars. To fabricate the electrodes, vertically standing gold nanopillars on gold films deposited on glass substrates were first formed. The nanopillars along with the underlying film were then patterned into electrodes (in a three-electrode design) and the electrodes were then enclosed in a PDMS chamber to form a fluidic sensor device. Of the three electrodes, one was used as enzyme electrode after functionalization with an enzyme (i.e. glucose oxidase) and the other two were used as working and counter electrodes, respectively. The performance of this fluidic glucose sensor was evaluated by measuring amperometric currents at various glucose concentrations. The nanopillar modified glucose sensor exhibited linear behavior with a sensitivity value as high as 35.9 μA cm−2 mM−1 in a concentration range from 0.25 to 2.5 mM. In comparison with a fluidic glucose sensor having only flat electrodes, the detection sensitivity for the sensor with nanopillar modified electrodes was five times higher.