Abstract:
This study compares the non-enzymatic glucose sensing performance by Cu2O nanorods/nanotubes
grown using electrochemically anodized Cu foam and Cu plates to form binder free one-dimensional
Cu(OH)2 nanostructures which were subsequently annealed at higher temperatures. Resulting Cu2O
nanorods/nanotubes had diameters between 100 and 200 nm and lengths in excess of 10 mm. The surface
morphology and structure of these thin films studied using scanning electron microscopy, X-ray
diffraction and energy dispersive X-ray spectroscopy showed that the copper foam based Cu2O structures
consisted of nanotubes/nanorods distributed over entire 3-dimensional space containing dense nano pores of size ~20 nm on outer surfaces. Cu plate based nanorods consisted of grooved macaroni type
surface morphologies. Non-enzymatic glucose sensing made using chronoamperometric and cyclic
voltammetric measurements showed that the Cu2O/Cu foam electrodes had a high sensitivity of
5792.7 mA mM 1 cm 2
, a very low detection limit of 15 nM (S/N ¼ 3), multi-linear detection ranges of
15 nMe0.1 mM and 575e4098.9 mM with a faster response time of less than 1 s. Cu plate based nanorods
showed a sensitivity of 141.9 mA mM 1 cm 2
, with a lower detection limit of 510 nM (S/N ¼ 3). The
significantly high sensitivity of Cu2O/Cu foam electrodes is attributed to the availability of increased
amount of active sites due to the large effective surface area provided by Cu2O nanorods/nanotubes. The
study also demonstrates the influence of the substrate on surface morphology of the nanorods/nano tubes. These Cu foam based Cu2O electrodes provide a promising platform for non-enzymatic glucose
detection with high specificity and reproducibility.
