Electrochemical Reversible Copper Oxide (CuO) System on Multiwalled Carbon Nanotube Paste Electrode (CPE) as Sensor for Hydrogen Peroxide in Wound Cleaning Solution

An electrochemical sensor for hydrogen peroxide (H2O2) was prepared and optimized in this study. The sensor recognition element consisted of mainly copper oxide (CuO) particles electrodeposited on an anodized multiwalled carbon nanotube paste electrode (MWCPE), which is composed of multiwalled carbon nanotubes (MWCNT) and polydimethylsiloxane (PDMS). Chronoamperometry (CA) was used as the electrodeposition technique both for Cu deposition and oxidation to CuO. The layer of CuO was shown to react with H2O2, which lead to measurable voltammetric current at varying concentrations of H2O2. Different parameters were optimized as follows: Cu deposition time, Cu oxidation time, and equilibration time. Differential pulse voltammetry (DPV) was used as the main sensing technique for CuO-CPE. DPV measurements showed that the average peak current (ave. Ip) was found to be increasing linearly with increasing H2O2 concentration. Two H2O2 concentration ranges, low concentration (20 μM – 100 μM) and high concentration (400 μM – 1200 μM), were observed to have a linear correlation with ave. Ip. The limits of detection (LODs) were calculated to be equal to 11.40 µM using the low concentration range, while 13.04 μM using the high concentration range. The H2O2 measurements using CuO-CPE were found to be reproducible and repeatable. Real sample analysis was also performed on a wound cleaning solution (aqua oxigenada, 6% H2O2 w/w) as a sample. From the measurements, the H2O2 concentration of the analyte was found to be 6.16% w/w; the calculated % error was equal to 2.67%. Overall, CuO-CPE composite was shown to be an effective electrochemical sensor for H2O2 analysis.