Real-Time, Selective Detection of Pb2+ in Water Using a Reduced Graphene Oxide/Gold Nanoparticle Field-Effect Transistor Device

A field-effect transistor (FET) device-based sensor is developed to specifically detect Pb2+ ions in an aqueous environment that is notably toxic. Reduced graphene oxide (rGO), as the semiconducting channel material, was utilized in the PET device through a self-assembly method. An L-glutathione reduced was employed as the capture probe for the label-free detection. By monitoring the electrical characteristics of the FET device, the performance of the sensor was measured and investigated. Compared with conventional detection technologies, this sensor enabled real-time detection with a response time of 1-2 s. A lower detection limit for Pb2+ ions as low as 10 nM was achieved, which is much lower than the maximum contaminant level for Pb2+ ions in drinking water recommended by the World Health Organization. Furthermore, the rGO PET sensor was able to distinguish Pb2+ from other metal ions. Without any sample pretreatment, the platform is user-friendly.