Graphene oxide sensors of high sensitivity fabricated using cold atmospheric-pressure hydrogen plasma for use in the detection of small organic molecules

Abstract

A novel electrochemical sensor was fabricated by means of solution-processed graphene oxide (GO) ink on fluorine-doped tin oxide (FTO), followed by rapid reduction of the GO surface to reduced graphene oxide (rGO) by cold diffuse atmospheric plasma generated in pure hydrogen gas. The FTO/rGO electrode was then employed in the detection of ascorbic acid, uric acid, dopamine, and acetaminophen molecules with low limits of detection; in these cases, 0.03, 0.06, 0.07, and 0.04 μM, respectively. While traditional methods for the reduction of GO are time-consuming, in the order of tens of minutes, and involve high-temperature (450 °C) sintering in argon, the novelty of this work lies in the rapid manufacture of the sensing material through cold plasma-assisted reduction of a GO surface. Since the temperature of the plasma procedure is below 70 °C, with the elapsed time lesser than 10 s, and the plasma unit is capable of processing an area of up to 160 cm2, FTO/rGO electrode preparation can be performed at high throughput. This fabrication method may be easily deployed in rapid and low-cost roll-to-roll manufacture, a factor essential for the future commercialization of cost-effective flexible and printed electronics based on a wide range of sensors.