Mass-producible disposable needle-type ion-selective electrodes for plant research.

Easily mass-producible needle-type Na and K ion-selective electrodes (ISEs) were developed for the direct and indirect measurement of Na and K ion concentrations in live plants. A polyimide strip with a silver layer on one side and Ag/AgCl formed at one end was used to construct two types of ISEs. For the type I ISE, an electrolyte layer was formed on the layer of silver and Ag/AgCl, which was then covered with a protecting layer.