Electrochemical characterization of reduced graphene oxide as an ion-to-electron transducer and application of screen-printed all-solid-state potassium ion sensors

We report potentiometric performances of ion-to-electron transducer based on reduced graphene oxide (RGO) for application of all-solid-state potassium ion sensors. A large surface area and pore structure of RGO are obtained by a hydrothermal self-assembly of graphene oxide. The extensive electrochemical characterization of RGO solid contact at the interface of ion-selective membrane and gold electrode shows that the potassium ion-selective electrode based on RGO had a high sensitivity (53.34 mV/log[K+]), a low detection of limit (- 4.24 log[K+], 0.06 mM) a good potential stability, and a high resistance to light and gas interferences. The potentiometric K+-sensor device was fabricated by combining of screen-printed electrodes and a printed circuit board. The K+-sensor device accurately measures the ion concentration of real samples of commercial sports drinks, coke and orange juice, and then transfers the collected data to a mobile application through a Bluetooth module. The screen-printed ion sensors based on RGO solid contact show a great potential for real-time monitoring and point-of-care devices in human health care, water-treatment process, and environmental and chemical industries.