Differential homogeneous immunosensor device

• US 4,916,075 A
• Filed: 08/19/1987
• Issued: 04/10/1990
• Est. Priority Date: 08/19/1987
• Status: Expired due to Fees

• Current Assignee: Omicron Technologies, Inc. (Biomedical Research Foundation of Northwest Louisiana)
• Original Assignee: Ohmicron Corp (Standard General LP)
• Inventors: Malmros, Mark K., Gulbinski, Julian III
• Primary Examiner(s): Kaplan, G. L.
• Application Number:
  US07/087,087
• Time in Patent Office: 965 Days
• Field of Search: 436/528, 436/531, 436/532, 436/151, 436/, 422/68, 435/7, 435/817, 435/291, 435/288, 324/71.5, 324/450, 324/, 204/403
• US Class Current: 435/287.2
• CPC Class Codes: G01N 33/54306 Solid-phase reaction mechanisms
• CPC Class Codes: G01N 33/5438 Electrodes
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

There is provided a novel method of testing for the presence of an analyte in a fluid suspected of containing the same. In this method, in the presence of the analyte, a substance capable of modifying certain characteristics of the substrate is bound to the substrate and the change in these qualities is measured.

While the method may be modified for carrying out quantitative differential analyses, it eliminates the need for washing analyte from the substrate which is characteristic of prior art methods.

Claims

1. A sensor means for conducting immunoassays comprising:

a film of semiconductive polymer having an obverse and reverse surface,

a common electroconductive area on the reverse surface in contact therewith,

at least one further electroconductive area of the same electroconductive material as in said common area on said reverse surface and in contact therewith,

at least one second further electroconductive area placed at a different location on the reverse surface and in contact therewith,

means for separating the obverse surface of the film in such a manner that the a first field is defined over said first electroconductive area and a second field is defined over said second electroconductive area while a portion of each of said fields lies over the said common electroconductive area.

2. A sensor means of claim 1 wherein the said first and second electroconductive areas are equidistant from the common area.

3. A sensor means of claim 1 wherein the said first and second electroconductive areas are equal in area.

4. A sensor means of claim 1 comprising:

a film of semiconductive polymer having an obverse and reverse surface,

a narrow electroconductive strip on the reverse surface in contact therewith, said strip dividing said film into two fields of equal area,

at least one further electroconductive area of the same electroconductive material as the said strip placed on said reverse surface and in contact therewith, on one field,

at least one second further electroconductive area placed on the remaining field on the reverse surface and in contact therewith in such a manner that the electroconductive areas on both fields are equally large and equidistant from the said strip.

5. A sensor means of claim 4 wherein the separating means on the obverse side of the film is

a masking layer of non conductive material placed on and in contact with the obverse surface of a film to provide unmasked areas of equal size on either side of the longitudinal axis of said strip and lying over at least an equal portion of that area occupied by each of said first and said second electroconductive areas in the fields on the reverse side of the film and over at least a portion of said strip.

6. A sensor means of claim 4 wherein the film is substantially circular and the first and second electroconductive areas are defined by the areas between the circumference of the circle and chords spaced apart from and at an equal inclination to the diameter which constitutes the longitudinal axis of said electroconductive strip.

7. An immunoassay sensor cell comprising a sensor means of claim 1,

electrical connection means to said electroconductive areas,

a sample reservoir having an open upper and lower end, the portion of said reservoir surrounding said open lower end being adapted to contact and form a liquid leakproof seal with the obverse surface of the film, of sufficient size to encompass at least the obverse surface over the electroconductive areas on the reverse side,

a dual chamber insert, adapted to fit removably inside said reservoir, having open upper and lower ends, the portion of said insert surrounding said open lower end being adapted to contact and form a liquid leakproof seal with the obverse surface of the film and being of sufficient size to encompass at least a part of the obverse surface over the electroconductive areas on the reverse side within said open lower end and having a center partition similarly adapted to contact and form a liquid leakproof seal with the obverse surface of the film.

8. A device of claim 7 wherein

the common electroconductive area is a narrow electroconductive strip on the reverse surface in contact therewith, said strip dividing said film into two fields of equal area,

and the first and second other electroconductive areas are

at least one further electroconductive area of the same electroconductive material as the said strip placed on said reverse surface and in contact therewith, on one field, and

at least one second further electroconductive area placed on the remaining field on the reverse surface and in contact therewith in such a manner that the electroconductive areas on both fields are equally large and equidistant from the said strip,

whereby said central partition defines two fields of equal area on either side of the longitudinal axis of the said strip, upon the obverse side of the film.