Development of electrochemical sensing system with carbon nanotube based electrode

Electrochemical sensing is a promising technique for various chemical and biochemical detection and quantification. Carbon nanotube (CNT) is a promising material for electrochemical electrodes due to its high reaction area and excellent electron transfer rate. In this work, CNT based electrode and low cost potentiostat are developed for a practical electrochemical sensing system. The developed electrochemical system was tested with standard KI solution for iodine ion detection by cyclic voltammetry (CV) measurement. Vertically aligned CNTs are selectively synthesized on 1 mm² window of gold coated SiO₂/Si electrode by thermal chemical vapor deposition (CVD) with gravity effect and water-assisted etching. For CV experiment, standard Ag/AgCl and platinum are used as reference and auxiliary electrodes, respectively. The electrochemical characteristics of KI were studies in borate buffer (pH 8.0). CV measurement is carried out with different KI concentrations ranging from 10^-4 to 10^-3 mol l^-1. From tested results, CNTs based electrode exhibit much higher sensitivity to KI than conventional gold electrode. Thus, the developed CNT electrode and system has been shown to be promising for the electrochemical sensing.