SENSOR DEVICE, A METHOD AND A SENSOR TO DETERMINE A RELATIVE CONCENTRATION OF A FIRST KIND OF IONS WITH RESPECT TO A SECOND KIND OF IONS SOLUTE IN A DROP OF LIQUID

摘要

A method to determine a relative concentration of a first kind of ions with respect to a second kind of ions solute in a drop of a liquid comprises providing a voltage to a measurement electrode and a counter electrode, the measurement electrode being provided over a semiconductor substrate comprising a plurality of channels, the channels connecting a cavity and the measurement electrode, wherein the counter electrode is arranged to be in contact with the cavity, when the cavity, the measurement electrode and the counter electrode are arranged to accommodate the drop of a liquid and allow a voltage to be applied to the drop of liquid. The method further comprises determining a current or a change of the current flowing through the drop of liquid in response to the applied voltage; and providing an evaluation signal indicative of the relative concentration based on the determined current or the determined change of current.