An aspect includes a low slope electrode device, including: at least one electrode; at least one container at least partially enclosing the at least one electrode and having at least one ion sensitive region; an external buffer container having at least one separating element that separates said at least one ion sensitive region into: a first ion sensitive area separating an internal buffer solution bathing the at least one electrode and an external sample solution; and a second ion sensitive area separating the internal buffer solution bathing the at least one electrode and an external buffer solution; wherein the at least one separating element, the first ion sensitive area, and the second ion sensitive area establish a charge flow circuit. Other aspects are described and claimed.