Method and biosensor for analysis

• US 20030059954A1
• Filed: 06/10/2002
• Published: 03/27/2003
• Est. Priority Date: 09/24/2001
• Status: Active Grant

• Current Assignee: Bionavis, Ltd.
• Original Assignee: Bionavis, Ltd.
• Inventors: Sadowski, Janusz, Vikholm, Inger
• Granted Patent: US 7,332,327 B2
• Time in Patent Office: Days
• US Class Current: 436/518
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: Y10S 435/808 Optical sensing apparatus
• CPC Class Codes: Y10S 435/962 Prevention or removal of interfering materials or reactants or other treatment to enhance results, e.g. determining or preventing nonspecific binding
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

In a method for analysis biomolecules (3) attached to a solid surface of a substrate (1) are used for detecting the presence of analytes (4) in a sample by binding of the analytes to the biomolecules. The biomolecules (3) are attached directly to the surface of the substrate together with biomolecule-repellent molecules (5), which cover the surface between the biomolecules (3) to prevent nonspecific binding of analytes (4) and other biomolecules. The invention relates also to a biosensor where biomolecules (3) are attached directly to the substrate (1) together with biomolecule-repellent molecules (5), which cover the surface between the biomolecules (3) to prevent non-specific binding of analytes (4) and other biomolecules. The biomolecules (5) can be self-assembled hydrophilic polymers. One example of using the invention is immunological analysis using surface plasmon resonance (SPR).

Claims

1. A method for analysis, where biomolecules (3) attached to a solid surface of a substrate (1) are used for detecting the presence of analytes (4) in a sample by binding of the analytes to the biomolecules, wherein the biomolecules (3) are attached directly to the surface of the substrate together with biomolecule-repellent molecules (5), which cover the surface between the biomolecules (3) to prevent non-specific binding of analytes (4) and other biomolecules.

2. A method as claimed in claim 1, wherein the biomolecule-repellent molecules (5) are attached to the surface of the substrate (1) covalently through functional groups, such as sulfide, disulfide or thiol groups.

3. A method as claimed in claim 1 or 2, wherein the substrate is a sensor substrate capable of inducing a change in a signal, indicative of an increase of an analyte (4) bound to the biomolecules (3) on its surface, the signal is applied to the substrate (1), the changed signal is detected, and the quantity of the analyte (4) bound to the biomolecules (3) on the surface of the substrate (1) is measured by means of the detected signal.

4. A method as claimed in any of claims 1 to 3, wherein in addition to biomolecules (3) and biomolecule-repellent molecules (5) attached directly to the surface of the substrate (1), separate particles (2) containing immobilized biomolecules are used, which attach to the substrate through analytes (4) bound to said biomolecules (3) on the substrate (1).

5. A method as claimed in any of the preceding claims, wherein the biomolecule (3) is a protein, a peptide, an enzyme, an antibody, a fragment of an antibody, an antigen or a part of an antigen, and the biomolecules are attached through thiol, disulfide or sulfide groups to the surface of substrate (1) and/or particles (2).

6. A method as claimed in any of the preceding claims, wherein the biomolecule-repellent molecule (5) is a polymer, especially a hydrophilic polymer.

7. A method as claimed in any of claims 3 to 6, wherein the substrate (1) is a substrate capable of providing a surface plasmon resonance (SPR) phenomenon, and the analysis is performed by SPR measurement.

8. A method as claimed in any of claims 3 to 6, wherein the analysis is performed by a thickness shear mode resonator, such as quartz crystal microbalance (QCM).

9. A method as claimed in any of the preceding claims, wherein the substrate (1) is a metal, a semiconductor or an electrically conductive polymer.

10. A method as claimed in any of the preceding claims, wherein the biomolecule (3) is an immunological binder molecule, such as an antibody or an immunologically active fragment thereof, and the analysis is an immunological analysis.

11. A biosensor for analysis, comprising a substrate and biomolecules (3) attached to a substrate (1), wherein the biomolecules (3) are attached directly to the substrate together with biomolecule-repellent molecules (5), which cover the surface between the biomolecules (3) to prevent non-specific binding of analytes (4) and other biomolecules.

12. A biosensor as claimed in claim 11, wherein the biomoleculerepellent molecules (5) are attached to the substrate covalently through functional groups, such as sulfide, disulfide or thiol groups.

13. A biosensor as claimed in claim 11 or 12, wherein the biomoleculerepellent molecules (5) are polymers, especially hydrophilic polymers.

14. A biosensor as claimed in any of claims 11 to 13, wherein the biomolecule-repellent molecules (5) are self-assembled on the surface.

15. A biosensor as claimed in any of claims 11 to 14, wherein the substrate is of a type capable of inducing a change in a signal, indicative of an increase of an analyte (4) bound to the biomolecules (3) on its surface, the sensor further comprising means for emitting the signal towards the substrate (1) and means for detecting the signal changed by the interaction with the substrate (1).

16. A biosensor as claimed in claim 15, wherein the substrate (1) is surface plasmon resonance (SPR) compatible material, the means for emitting the signal being light emitting means and the means for detecting the signal being one or plurality of light detectors provided for detection of the signal reflected from the interface between the substrate and a dielectric material.

17. A biosensor as claimed in claim 15, which is a thickness shear mode resonator sensor, such as quartz crystal microbalance (QCM) sensor.