Nonenzymatic Hydrogen Peroxide Electrochemical Sensor Based on Inkjet-Printed Reduced Graphene Oxide

Abstract

The vital role of hydrogen peroxide (H2O2) in many enzyme-catalyzed reactions, has attracted much interest to develop novel approaches for accurate and fast detection of this simple compound [2]. Also, the determination of the hydrogen peroxide level is essential in food processing, environmental analysis, and clinical diagnosis [2]. Reduced graphene oxide (rGO) has shown to be a superior electrode material for electrochemical analysis due to its high electron transfer rate and active surface area [3]. However, the fabrication of such rGO-based electrodes involves complicated and expensive fabrication processes. Herein, we present a disposable, simple, and low-cost H2O2 electrochemical sensor based on rGO for amperometric detection of hydrogen peroxide concentration.First, the rGO ink material was prepared by mixing 10 ml of graphene oxide (GO) solution with 10 ml of DI water, and sodium dodecyl sulfate (2 mg/ml). The SDS works as a surfactant and reduces the possibility of printer nozzle clogging. The solution was sonicated for 30 minutes and was loaded to a cartridge of an office inkjet printer. To achieve a thicker layer of GO, the printing process was repeated 25 times on a PET film. Next, the electrodes were placed inside hydroiodic (HI) acid for 24 hours at 100 oC to remove oxygenated groups from GO molecular structure. The color of the electrodes became darker after the GO was reduced to rGO (Figure 1.A). Then, the printed pattern was sliced into 20 by 2.5 mm electrodes, and the resistance of the electrode was measured to validate the reduction process.The step voltammetry method was adopted to measure the H2O2 inside 0.1 M PBS buffer. The solution was stirred at 200 rpm, and -800 mV vs. Ag/AgCl was applied to the working electrode. As it is shown in Figure 1.B, after the addition of 100 µM of H2O2, the current increases due to the reduction of H2O2. Finally, the selectivity of the sensor was evaluated against ascorbic acid and glucose.In summary, the rGO-based electrochemical sensor was fabricated by inkjet printing graphene oxide with a regular office inkjet printer followed by chemical reduction procedure. The sensor was used to determine the hydrogen peroxide level in aqueous solution. Inkjet-printed rGO electrodes can be used for simple and precise measurement of hydrogen peroxide with high selectivity and sensitivity.