Sensors & Transducers (Nov 2010)
Electrochemical Detection of Mn(II) and Cd(II) Mediated by Carbon Nanotubes and Carbon Nanotubes/Li+ Modified Glassy Carbon Electrode
Abstract
Glassy carbon electrode (GCE) was modified with carbon nanotubes (CNT) with and without a Li+ dopant by using a mechanical attachment method; CNT/Li+/GCE was used as two working electrodes, by doping CNT/GCE with Li+. The nano-structure of the electrodes showed individual voltammetrics of Mn2+ with two reduction peaks at +800 and +100 mV. Two reduction peaks for Cd2+ appeared at +600 V and -800 mV with one oxidation peak at -600 mV. The reduction current of Mn2+ and the redox current of Cd2+ on the CNT/Li+/GCE were largely influenced by a low concentration comparison with GCE and CNT/GCE. It showed that the detection of Mn2+ and Cd2+ by CNT/Li+/GCE in an aqueous solution of 0.1M KCL, with a relative standard deviation (RSD) of the electrode being very good CNT/Li+/GCE. The determination of efficiency for the best modified electrode was detected for Mn2+ and Cd2+ on CNT/Li+/GCE; it was also found to have a wide linear range and good repeatability with a relative standard deviation (RSD) of ±1.9 % when this electrode was used and the limit of detection was found to be 10-4 to 10-3 mM of Mn2+ and 10-4 to 10-2 mM of Cd2+, while the range of detection was found to be 3x10-4 to 10-3 mM and 10-3 to 10 -2 mM when using the CNT/GCE for Mn2+and Cd2+, respectively, with an RSD of ±3.3 % for Mn2+ and Cd2+.
