Fig. 5. (a) CV response of bare GCE (red) and NiCo2O4 nanoneedle/GCE (blue) in 0.1 M urea, and response of bare GCE in blank 0.1 M NaOH (black). Inset: nanoneedle/GCE in 0.1 M NaOH. (b) Anodic peak current of various CV runs versus the square root of the scan rate. Inset: CV response of the NiCo2O4 nanoneedle/GCE electrode in 1 mM urea at different scan rates.
