A Paper-Based Electrochemical Sensor Array for Detection of Hydrogen Peroxide

Abstract

A sensitive and rapid detection of hydrogen peroxide (H2O2) is important in biomedical, food, and environmental analysis. The enzyme-based electrochemical detection of H2O2 may provide simple, accurate, and rapid process; however, due the thermal and chemical deformation of enzymes during the fabrication process, these sensors may suffer from instability [1]. Recently, some particles which has electrocatalytic properties toward H2O2 has been employed to develop electrochemical sensors. Of these, iron oxide (Fe3O4) and copper oxide (CuO) nanoparticles have shown good electrocatalytic properties toward H2O2 [2, 3]. However, one common drawback of these sensors is lack of selectivity owing to the fact that these catalysts shows electrocatalytic properties toward various analytes in the solution. Here, we present a novel paper-based electrochemical sensor based on modified carbon nanotube electrode, which can reduce the matrix effect in multi-analyte solutions. Paper-based sensors have become of great interest for fabricating inexpensive, simple, and disposable sensors. Carbon nanotube electrode ink has been modified using CuO and Fe3O4, and an electrode array made of modified and bare carbon ink solutions is developed by utilizing screen-printing of carbon ink solutions on paper. Figure shows the developed paper-based sensor array design. Moreover, a multichannel potentiostat circuit has been developed in order to investigate the amperometric response of the sensor array on H2O2 solution. The potentiostat can control three working electrodes independently, and it is also working with a USB port as power source. Since these modified electrodes show a unique response to different electroactive species, the results can be interpreted using a statistical method to compromise the interference from other electroactive species in the solution. Further, solutions with various concentration of H2O2 and interfering species has been tested using the portable potentiostat in order to assess the matrix effect originated from the interfering species in H2O2 detection.