Electrochemical potentiometric sensing without reference electrode

Abstract

The invention relates to a method of determining a charged particle concentration in an analyte (), the method comprising steps of: i) determining at least two measurement points of a surface-potential versus interface-temperature curve (c, c, c, c), wherein the interface temperature is obtained from a temperature difference between a first interface between a first ion-sensitive dielectric (Fsd) and the analyte () and a second interface between a second ion-sensitive dielectric (Ssd) and the analyte (), and wherein the surface-potential is obtained from a potential difference between a first electrode (Fe) and a second electrode (Se) onto which said first ion-sensitive dielectric (Fsd) and said second ion-sensitive dielectric (Ssd) are respectively provided, And ii) calculating the charged particle concentration from locations of the at least two measurement points of said curve (c, c, c, c). This method, which still is a potentiometric electrochemical measurement, exploits the temperature dependency of a surface-potential of an ion-sensitive dielectric in an analyte. The invention further provides an electrochemical sensor for determining a charged particle concentration in an analyte. The invention also provides various sensors which can be used to determine the charged particle concentration, i.e. EGFET's and EIS capacitors.