The Effect of Electrochemical Pretreatment on the Sensing Performance of Single Walled Carbon Nanotubes

In this paper, we report the effect of subsequent electrochemical anodization and cathodization subjected to single walled carbon nanotubes. The performance of the single walled carbon nanotubes before and after activation was evaluated electrochemically using different charged redox probes and a biologically important neurotransmitter-dopamine. Further, for the first time, the surface of single walled carbon nanotubes before and after electrochemical activation was also evaluated using Raman Spectroscopy. Electrochemical results indicated that the pretreatment method employed in this work greatly enhanced the performance of single walled carbon nanotubes towards the detection of the model analytes employed. The observed enhancement in the signal is attributed to the rupture of the basal plane found on the end caps of carbon nanotubes giving rise to a larger density of edge-plane like defects on the single walled carbon nanotubes surface. A detection limit of 10 nM (based on three times the standard deviation of the slope) was also estimated when dopamine was monitored using electrochemically activated single walled carbon nanotube electrodes. In addition, the electrochemically activated carbon nanotubes exhibited a improved selective and sensitive detection of our model analyte dopamine with a minimal electrode fouling of about 3% +/- 1.2% (N = 4).