Graphene oxide microstrip antenna-based sensor for oxygen gas sensing in medical applications

In this work, we report the development of a new graphene oxide (GO) sensor based on a microstrip antenna for detecting and measuring O 2 concentration. GO was prepared from natural graphite powder using a modified Hummers procedure and then deposited upon a phenolic substrate to act as the sensing element of the designed device. Detection tests employing the sensor to evaluate oxygen gas (O 2 ) in higher concentrations were performed, whereas it was observed that the two operating frequencies of the device was displaced to higher values as the concentration oxygen gas increased. The effect of relative humidity (RH) in the response sensor too was observed, whereas the 9.704 GHz mode demonstrating to be the most sensitive to O 2 variation after sensitivity values have been corrected, presenting limit of detection (LOD) equal to 0.38%O 2 . Evaluating the results, it is possible to note that the device studied could be used as sensor in medical equipment operating at elevated oxygen concentrations, such as ventilators, O 2 concentrators, and other medical equipment. Moreover, evaluated sensor would be a promisor candidate for healthcare monitoring applications for the reason that this device could act as both an O 2 sensor and antenna, and thus transmitting their information to other devices.