Electrochemical assays

• US 20040020791A1
• Filed: 01/28/2003
• Published: 02/05/2004
• Est. Priority Date: 11/21/1997
• Status: Abandoned Application

• Current Assignee: Inverness Medical Switzerland GmbH (Abbott Laboratories)
• Original Assignee: Inverness Medical Switzerland GmbH (Abbott Laboratories)
• Inventors: Porter, Robert Andrew, Badley, Robert Andrew
• Application Number:
  US10/353,721
• Publication Number:
  US 20040020791A1
• Time in Patent Office: Days
• US Class Current: 205/777.5
• CPC Class Codes: C07D 209/86 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the ring system
• CPC Class Codes: C07K 16/26 against hormones ; against hormone releasing or inhibiting factors
• CPC Class Codes: C07K 16/44 against material not provided for elsewhere , e.g. haptens, metals, DNA, RNA, amino acids
• CPC Class Codes: C07K 2317/22 from camelids, e.g. camel, llama or dromedary
• CPC Class Codes: C07K 2317/31 multispecific
• CPC Class Codes: C07K 2317/622 Single chain antibody (scFv)
• CPC Class Codes: C07K 2319/00 Fusion polypeptide
• CPC Class Codes: G01N 33/5438 Electrodes
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property

Abstract

Disclosed is a component for a device for detecting the presence of an analyte of interest in a sample, the component comprising an electrically conducting solid support having immobilised thereon a chemical moiety, said chemical moiety comprising an electroactive portion with an electrochemical property capable of being directly modulated in a detectable manner by the binding thereto of a binding partner having a specific binding activity for the electroactive portion, together with apparatus comprising the component, and a method of detecting the presence of an analyte of interest.

Claims

1. A component for a device for detecting the presence of an analyte of interest in a sample, the component comprising an electrically conducting solid support having immobilised thereon a chemical moiety, said chemical moiety comprising an electroactive portion with an electrochemical property capable of being directly modulated in a detectable manner by the binding thereto of a binding partner having a specific binding activity for the electroactive portion.

2. A component according to claim 1, wherein the electrically conducting solid support comprises gold, platinum, metal oxide, carbon/graphite, silicon or silicate.

3. A component according to claim 1 or 2, wherein the modulation of the electrochemical property involves oxidation or reduction of the chemical moiety.

4. A component according to any one of claims 1, 2 or 3, wherein the electroactive portion comprises an immunogen or a hapten, and the binding partner comprises an immunoglobulin or an effective antigen-binding portion thereof with binding specificity for the electroactive portion.

5. A component according to any one of the preceding claims, wherein the chemical moiety comprises an organic, moderately hydrophobic entity.

6. A component according to any one of the preceding claims, wherein the chemical moiety comprises a conjugated system of delocalized electrons.

7. A component according to any one of the preceding claims, wherein the chemical moiety comprises an organometallic compound or a heteroaromatic compound.

8. A component according to any one of the preceding claims, wherein the chemical moiety comprises a monomer, dimer or polymer comprising one or more of the following:

carbazoles, ferrocenes, pyrroles, furans, and thiophenes.

9. A component according to any one of the preceding claims, wherein the electroactive portion of the chemical moiety is separated from the electrically conducting solid support by a pendant chain portion.

10. A component according to claim 9, wherein the pendant chain portion comprises a conjugated system of delocalised electrons, to facilitate transport of electrons between the electroactive portion and the electrically conducting solid support.

11. A component according to claim 9, wherein the pendant chain portion is alkyl, alkenyl, or substituted alkyl or alkenyl.

12. A component according to claim 11, wherein the chain portion conforms to the general formula (—

CH₂—

)_n, where n is an integer from 3 to 14, preferably from 5 to 12, inclusive.

13. A component according to any one of the preceding claims, wherein the chemical moiety is a molecule which can form a self-assembling monolayer on the electrically conducting solid support.

14. An assay device for detecting the presence of an analyte of interest, comprising a component in accordance with any one of the preceding claims.

15. An assay device according to claim 14, further comprising one or more of the following:

sample receiving means for accepting a sample under test;

a binding partner having specific binding activity for the electroactive portion of the chemical moiety;

detection means for detecting a modulation in an electrochemical property of the electroactive portion of the chemical moiety;

data processing means for processing data output from the detection means; and

data display means for displaying the assay result.

16. An assay device according to claim 14 or 15, comprising a binding partner releasably immobilised on a solid support, said binding partner having specific binding activity for the electroactive portion of the chemical moiety, and being released from the solid support in the presence of the analyte of interest.

17. A component for use in a device according to claim 14, said component comprising a solid support having releasably immobilised thereon a binding partner having specific binding activity for an electroactive portion of chemical moiety, the binding partner being released from the solid support in the presence of the analyte of interest, and wherein binding of the binding partner to the electroactive portion directly modulates an electrochemical property of the electroactive portion in a detectable manner.

19. A method according to claim 18, comprising use of a component according to any one of claims 1-13, or an assay device according to any one of claims 14, 15 or 16.

18. A method of detecting the presence of an analyte of interest in a sample, the method comprising the steps of:

providing an electrically conducting solid support having immobilised thereon a chemical moiety having an electroactive portion with an electrochemical property capable of being modulated in a detectable manner directly by the binding thereto of a binding partner having specific binding activity for the electroactive portion; and

causing the binding partner to contact the electroactive portion of the chemical moiety as a result of the presence in the sample of the analyte of interest.

20. A method according to claim 18 or 19, wherein the binding partner is present as a binding entity and comprises a first specific binding activity for the electroactive portion of the chemical moiety, and a different, second specific binding activity.

21. A method according to any one of claims 18, 19 or 20, wherein the binding partner comprises a bispecific antibody or bispecific antigen-binding immunoglobulin portion.

22. A chemical moiety, comprising an electroactive portion, having the structure shown in FIG. 13 wherein R₁ and R₂ are, indepenently, H;

OH;

C₁-C₁₄ alkyl, aryl, alkenyl or alkoxy (all optionally substituted);

halide;

amide;

or amine; and

further wherein the heteroaromatic ring structure may be optionally substituted at one or more positions with alkyl, aryl, alkenyl, or alkoxy groups (all themselves optionally substituted), acid groups (organic or inorganic), halide, amide or amine.

23. A chemical moiety according to claim 22, wherein R₁ is alkyl, preferably ethyl, propyl or butyl.

24. A chemical moiety according to claim 22 or 23, wherein R₂ is C₁-C₁₂ alkyl, preferably C₄-C₈ alkyl.

25. A chemical moiety according to any one of claims 22, 23 or 24, wherein R₁ or R₂ is substituted so as to comprise a terminally positioned reactive substituent thiol, carboxyl, amide, amine, halide, aldehyde, ketone, epoxide, or succinimide group, or other protein coupling agent which facilitates coupling of the moiety to other entities.

26. A molecule having specific binding activity for a chemical moiety in accordance with any one of claims 22-25.

27. A molecule according to claim 26, comprising an immunoglobulin molecule or an effective portion thereof.

28. A molecule according to claim 26 or 27, comprising at least one further specific binding activity, which further specific binding activity is for an analyte of interest of for an antibody directed against an analyte of interest.