IMPEDIMETRIC SENSOR AND APPLICATIONS THEREOF

• US 20100193378A1
• Filed: 04/29/2008
• Published: 08/05/2010
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: Consejo Superior de Investigaciones Científicas,
• Original Assignee: Consejo Superior de Investigaciones Científicas,
• Inventors: Sanchez Baeza, Francisco José, Bratov, Andrei, Abramova, Natalia, Domínguez Horna, Carlos, Ramon Azcon, Javier, Marco Colas, María Pilar, Merlos Domingo, Ángel
• Granted Patent: US 8,608,919 B2
• Time in Patent Office: Days
• US Class Current: 205/792
• CPC Class Codes: G01N 27/3276 being a hybridisation with immobilised receptors using a FET type sensor G01N27/4145; concerning the hybridisation C12Q1/68
• CPC Class Codes: G01N 33/54306 Solid-phase reaction mechanisms
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

The invention relates to a highly sensitive impedimetric sensor in which the highly conductive electrodes are separated by a barrier of insulating material. Said sensor is used to determine directly the presence of analytes in a biological sample of human, veterinary or environmental origin.

Claims

1. A useful biosensor for directly determining the presence of analytes in a sample characterised in that it comprises:

i) an insulating substrate or cover with an insulating layer,

ii) at least, a pair of chemically inert interdigitated electrodes and formed with a highly conductive electrical material, disposed on the substrate and each pair of digits separated by

iii) a barrier made of an insulating material, whose height is similar to the distance existing between the centres of the pair of adjacent digitated electrodes, into which the welding points open, and

iv) chemically immobilised receptor molecules on the surface of the insulating material or on the surface of the electrodes.

2. The biosensor according to claim 1, wherein the receptor molecule belong to the following group:

enzymes, antibodies, antigens, peptides, DNA fragments, RNA fragments or oligonucleotides.

3. The biosensor according to claim 1, wherein the substrate from i) is of a material belonging to the following group:

a polymer, a glass or an inorganic oxide.

4. The biosensor according to claim 1, wherein the substrate from i) is not of an insulating material but comprises an insulating or dielectric layer of a material belonging to:

silicon dioxide or a polymer.

5. The biosensor according to claim 1, wherein the highly conductive and inert electrodes from ii) are of a material belonging to the following group:

metals, preferably Pt, Pd and Au, oxides, Si, silicon polycrystalline, tantalum silicide and polymer conductors.

6. The biosensor according to claim 1, wherein the electrodes have digits with a width and a separation between them between the ranges of 0.5 to 10.0 μ

m.

7. The biosensor according to claim 1, wherein the insulating barrier from iii) is of a material belonging to the following group:

inorganic oxides, polymers and materials sensitive to the exposure of UV light.

8. The biosensor according to claim 1, wherein the insulating barrier from iii) features a thickness of the insulating layer, which defines the height of the barrier which separates two adjacent digits, which means that it is between 50% and 150% of the distance which separates the centres of a pair of consecutive digitated electrodes, or more preferably, close to 100%.

9. The biosensor according to claim 1, wherein the receptor molecules from iv) are immobilised on the surface of the electrodes.

10. The biosensor according to claim 1, wherein the electrodes are organized according to an interdigitated array.

11. The biosensor according to claim 1, further comprising a device or an apparatus which detects the electrical properties connected to the electrodes from ii) whereto is applied an AC voltage, and which detects the variation in the electrical field close to the surface of the barriers, and a device or apparatus to apply said voltage.

12. The biosensor according to claim 11, wherein the detection device is an impedimeter which measures the impedance between the electrodes of the sensor.

13. according to claim 1, further comprising at least one biomolecular sensor, whether it is because they are different types of biomolecules, for example, a nucleic acid (for example, a probe or an oligonucleotide), antigens, antibodies, enzymes, proteins or peptides, or because being of the same type of molecule they head towards one or more different analytes.

14. A method for analyzing a biological sample, which comprises using the biosensor of claim 1.