ELECTROCHEMICAL POTENTIOMETRIC SENSING WITHOUT REFERENCE ELECTRODE

• US 20110208457A1
• Filed: 08/24/2009
• Published: 08/25/2011
• Est. Priority Date: 08/25/2008
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Curatola, Gilberto, Merz, Matthias, Ponomarev, Youri Victorovitch
• Granted Patent: US 8,801,917 B2
• Time in Patent Office: Days
• US Class Current: 702/65
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors
• CPC Class Codes: G01N 27/4148 Integrated circuits therefor, e.g. fabricated by CMOS processing CMOS processing per se H01L21/82

Abstract

The invention relates to a method of determining a charged particle concentration in an analyte (100), the method comprising steps of: i) determining at least two measurement points of a surface-potential versus interface-temperature curve (c1, c2, c3, c4), wherein the interface temperature is obtained from a temperature difference between a first interface between a first ion-sensitive dielectric (Fsd) and the analyte (100) and a second interface between a second ion-sensitive dielectric (Ssd) and the analyte (100), 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 (c1, c2, c3, c4). 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 deny 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.

Claims

1. An electrochemical sensor for determining a charged particle concentration in an analyte, the electrochemical sensor comprising:

a first electrode with a first ion-sensitive dielectric provided thereon, the first electrode being arranged for contacting the analyte via the first ion-sensitive dielectric to obtain a first interface between the first ion-sensitive dielectric and the analyte;

a second electrode with a second ion-sensitive dielectric provided thereon, the second electrode being arranged for contacting the analyte via the second ion-sensitive dielectric to obtain a second interface between the second ion-sensitive dielectric and the analyte, and

a control means for measuring a potential difference between the first electrode and the second electrode at least two different values of a temperature difference between the first interface and the second interface to obtain at least two measurement points of a surface-potential versus interface-temperature curve.

2. An electrochemical sensor as claimed in claim 1, wherein the control means comprises a temperature setting means arranged for setting the temperature difference between the first interface and the second interface to said at least two different values.

3. The electrochemical sensor as claimed in claim 1, wherein a semiconductor layer is provided between the first electrode (Fe) and the first ion-sensitive dielectric.

4. The electrochemical sensor as claimed in claim 1, further comprising a transducer for measuring said potential difference.

5. The electrochemical sensor as claimed in claim 4, wherein the transducer comprises a differential amplifier connected with its inputs to said first electrode and said second electrode or a transistor connected with its gate to said first electrode and with its source to the second electrode.

6. The electrochemical sensor as claimed in claim 1, wherein the control means comprises a controller, the controller being coupled to the first electrode and being arranged for initiating the measuring of the potential difference between the first electrode and the second electrode at said at least two different values to obtain at least two measurement points of a surface-potential versus interface-temperature curve.

7. The electrochemical sensor as claimed in claim 6, wherein the controller comprises a temperature sensor for measuring the at least two different values of the temperature difference, and wherein the controller is further arranged for initiating the measuring of the surface-potential at a desired value of the temperature difference.

8. The electrochemical sensor as claimed in claim 6, wherein the controller comprises storage means for storing the respective measured values of the surface-potential and, optionally, the respective values of the temperature difference between the first interface and the second interface.

9. The electrochemical sensor as claimed in claim 6, wherein the controller comprises a processor unit for calculating the charged particle concentration from the at least two measurement points of said curve.

10. The electrochemical sensor as claimed in claim 1, wherein at least the first ion-sensitive dielectric is further provided with a probe molecule layer comprising probe molecules, such as antibodies, and DNA/RNA strands, the probe molecule layer being in direct contact with the analyte in operational use, the first ion-sensitive dielectric thereby being configured for binding charged target molecules for enabling to determine a charged target molecule concentration in the analyte.

11. A semiconductor device comprising the electrochemical sensor as claimed in claim 1, the semiconductor device comprising a semiconductor body and at least one interconnect layer, wherein the first electrode and the second electrode are located in the at least one interconnect layer, and wherein the control means are located in the semiconductor body and/or the at least one interconnect layer.

12. An RF-ID tag comprising the electrochemical sensor as claimed in claim 1.

13. A method of determining a charged particle concentration in an analyte, the method comprising steps of:

determining at least two measurement points of a surface-potential versus interface-temperature curve, wherein the interface temperature is obtained from a temperature difference between a first interface between a first ion-sensitive dielectric and the analyte and a second interface between a second ion-sensitive dielectric and the analyte, and wherein the surface-potential is obtained from a potential difference between a first electrode and a second electrode onto which said first ion-sensitive dielectric and said second ion-sensitive dielectric are respectively provided, and

calculating the charged particle concentration from locations of the at least two measurement points of said curve.

14. The method as claimed in claim 17, wherein the step of determining of said curve comprises sub-steps of:

setting the temperature difference to a first value;

determining a first value of the potential difference, wherein the first value of the temperature difference and the first value of the potential difference together define a first respective one of the measurement points of said curve;

setting the temperature difference to a second value different from the first value, and

determining a second value of the potential difference at the interface, wherein the second value of the temperature difference and the second value of the potential difference together define a second respective one of the at least two measurement points of said curve.