Solid-contact K+-selective electrode based on three-dimensional molybdenum sulfide nanoflowers as ion-to-electron transducer

Three-dimensional (3D) molybdenum sulfide (MoS2) nanoflowers have been synthesized via a novel hydrothermal method and applied as ion-to-electron transducer for solid-contact ion-selective electrodes (SC-ISEs). The morphology and elemental composition of the prepared nanomaterials have been characterized. The performance of the developed K+-SC-ISE has been demonstrated by determining K+ in solution with a polymeric membrane containing valinomycin as the ionophore. A Nernstian slope of 55.8 mV/decade with a detection limit of 10−5.5 M can be obtained. Using the 3D flowerlike MoS2 as solid contact, the fabricated K+-SC-ISE exhibits a smaller impedance and more stable potential response than the coated-wire electrode. In addition, the novel SC-ISE behaves well in the water layer test and shows good resistance to interferences from light, O2 and CO2. It is believed that the 3D MoS2 nanoflowers can be a good alternative as solid contact in SC-ISEs.