Microvolume immunoabsorbant assays with amplified electrochemical detection

• US 6,887,714 B2
• Filed: 10/15/2001
• Issued: 05/03/2005
• Est. Priority Date: 10/16/2000
• Status: Expired due to Term

• Current Assignee: University of Arkansas Board of Directors
• Original Assignee: Board of Trustees of The University of Arkansas NA
• Inventors: Beittle, Robert Jr., Fritsch, Ingrid
• Primary Examiner(s): Chin, Christopher L.
• Assistant Examiner(s): Lam, Ann Y
• Application Number:
  US09/978,734
• Publication Number:
  US 20020058279A1
• Time in Patent Office: 1,296 Days
• Field of Search: 436/518, 436/514, 436/540, 436/523, 436/524, 436/525, 436/535, 435/4, 435/5, 435/6, 435/7.1, 435/7.2, 435/7.21, 435/7.22, 435/7.32, 435/7.4, 435/7.6, 435/7.72, 435/7.8, 435/7.9, 435/7.91, 435/7.92, 435/7.93, 435/7.94, 435/7.95, 435/287.3, 435/289.1, 435/7.5, 435/7.7, 435/7.71, 422/50, 204/400, 204/403
• US Class Current: 436/518
• CPC Class Codes: B01F 33/3032 using magneto-hydrodynamic [MHD] phenomena to mix or move the fluids
• CPC Class Codes: B01J 19/0046 Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays synthesis methods per se C40B50/00
• CPC Class Codes: B01J 2219/00317 Microwell devices, i.e. having large numbers of wells
• CPC Class Codes: B01J 2219/00511 Walls of reactor vessels
• CPC Class Codes: B01J 2219/00585 Parallel processes
• CPC Class Codes: B01J 2219/00596 Solid-phase processes
• CPC Class Codes: B01J 2219/00653 the compounds being bound to electrodes embedded in or on the solid supports
• CPC Class Codes: B01J 2219/00659 Two-dimensional arrays
• CPC Class Codes: B01J 2219/00704 integrated with the reactor apparatus
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: B01L 3/5085 for multiple samples, e.g. microtitration plates
• CPC Class Codes: C12Q 2565/607 being a sensor, e.g. electrode
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: G01N 27/3277 being a redox reaction, e.g. detection by cyclic voltammetry voltammetry per se G01N27/42, G01N27/48
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

A structure and method for chemical sensing utilizing microassays. Microcavities or micropores are combined with assay techniques to provide a very fast and very sensitive means of detecting chemical compounds. Assay techniques are modified to include a metal ion binding carrier species especially suitable for use in conjunction with the electrochemical detection. This allows assays to be combined with electrochemical analysis, thus allowing the high speed ease and hypersensitivity available in the invention disclosed herein.

Claims

1. A method for quantitating or detecting the presence or absence of an analyte comprising:

addition of a sample to a microassay structure having at least one electrode and an analyte binding material;

allowing an analyte in said sample to bind to said analyte binding material in said microassay structure;

rinsing said microassay structure such that said analyte remains bound to said analyte binding material while the remainder of said sample is removed;

addition of an analyte binding molecule having a carrier species attached wherein said carrier species includes an electroactive species capable of generating a current by either accepting or transmitting one or more electrons to the at least one electrode and wherein said carrier species may be activated such that it releases the electroactive species;

allowing said analyte binding molecule to bind to said analyte;

activating said carrier species wherein said activation of said carrier species is selected from the group consisting of change in temperature, change in pH, and addition of an activating compound; and

,

measuring a current through said microassay structure by means of the at least one electrode within the microassay structure thereby quantitating or detecting the presence or absence of the analyte.

2. The method of claim 1 wherein said carrier species is a metallo protein and the electroactive species is a metal ion.

3. The method of claim 1 wherein said carrier species is a metal ion carrying dendrimer and the electroactive species is a metal ion.

4. The method of claim 1 wherein said carrier species is selected from the group consisting of metallo-protein, dendrimer or chelating agents.

5. The method structure claim 1 wherein the microassay structure further comprises a microcavity having an opening and a lipid bilayer suspended across the opening of said microcavity.

6. The method of claim 1 wherein the analyte binding materials in said microassay structure is selected from the group consisting of a primary antibody, a polynucleotide, polystyrene, a self-assembled monolayer or a ligand.

7. The method of claim 1 wherein the analyte binding molecule is selected from the group consisting of a secondary antibody, a protein, or a ligand.