Electropolymerizable film, and method of making and use thereof

• US 6,180,346 B1
• Filed: 03/12/1999
• Issued: 01/30/2001
• Est. Priority Date: 06/27/1995
• Status: Expired due to Term

• Current Assignee: University of North Carolina At Chapel Hill (University of North Carolina System)
• Original Assignee: University of North Carolina At Chapel Hill (University of North Carolina System)
• Inventors: Ontko, Allyn C., Thorp, H. Holden
• Primary Examiner(s): Fredman, Jeffrey
• Assistant Examiner(s): CHAKRABARTI, ARUN K
• Application Number:
  US09/267,552
• Time in Patent Office: 690 Days
• Field of Search: 204/153.12, 204/403, 204/412, 435/288, 435/291, 435/810, 435/817, 435/6
• US Class Current: 204/403.15
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C12Q 1/6816 characterised by the detection means C12Q1/6804 takes precedence
• CPC Class Codes: C12Q 1/6825 Nucleic acid detection involving sensors
• CPC Class Codes: C12Q 2525/197 incorporating a spacer/coupling moiety
• CPC Class Codes: C12Q 2563/113 the label being electroactive, e.g. redox labels
• CPC Class Codes: Y10S 435/81 Packaged device or kit
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

An electrode and method of preparing an electrode by electropolymerizing a film on the conductive working surface of an electrode. The electrode is modified by reductive electropolymerization of a thin film of poly[Ru(vbpy)₃²⁺] or poly[Ru(vbpy)₃²⁺/vba] (vbpy=4-vinyl-4′methyl-2,2′-bipyridine and vba=p-vinylbenzoic acid) and the electrode is used for the electrochemical detection of aqueous GMP, poly[G], and surface immobilized single-stranded DNA probes. The film is formed from a co-polymer of a mediator such as Ru(vbpy)₃²⁺ and a functionalized moiety having a carboxylate group such as p-vinylbenzoic acid. A DNA probe is attached covalently to the carboxylate group via a carbodiimide reaction followed by amidation of an amino-linked single-stranded DNA. In the presence of these guanine containing moieties, a dramatic enhancement in the oxidative current for the Ru^3+/2+ couple (present in the polymeric thin film) due to the catalytic oxidation of guanine is observed.

Claims

1. An electrode useful for the electrochemical detection of a nucleic acid, comprising:

(a) a thin film that contains a metal complex, wherein said metal complex is an electropolymerization initiator, and wherein said metal complex is a mediator for the oxidation of a preselected base in the nucleic acid; and

(b) functionalized moiety as part of said film to which the nucleic acid can be attached.

2. The electrode of claim 1, wherein the metal complex is selected from the group consisting of poly[Ru(vbpy)₃²⁺] and poly[Ru(vbpy)₃²⁺/vba], wherein vbpy is 4-vinyl-4′

methyl-2,2′

-bipyridine and vba is p-vinylbenzoic acid.

3. An electrode useful for the electrochemical detection of a preselected base in a nucleic acid, said electrode comprising:

(a) a substrate having a conductive working surface; and

(b) an electropolymerized film on said conductive working surface, said electropolymerized film comprising a co-polymer of a (i) a mediator for the oxidation of a preselected base in a nucleic acid; and

(ii) a functionalized moiety having a carboxylate group to which the nucleic acid can be attached.

4. The electrode of claim 3, wherein the mediator is Ru(vbpy)₃²⁺ and the functionalized moiety is p-vinylbenzoic acid.