Electrochemical lateral flow immunological test method, sensor for same, and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-12411136-B2
Application number	US-202017786705-A
Country	US
Kind code	B2
Filing date	Dec 15, 2020
Priority date	Dec 18, 2019
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

In an electrochemical lateral flow immunological test method, flow of a sample solution is controlled. As a result, the reaction time is short and quantitative measurements and electrical measurements can be performed with excellent sensitivity and high accuracy, and the invention provides a sensor employed in the method. Electrode portions, electrically conductive portions for transferring electric current from the electrode portions, and connecting portions connected to an electrical measuring instrument for measuring the electric current values are arranged on a supporting body including a resin sheet, pads and the like disposed by partial lamination on the supporting body. A sample solution flows over the plurality of pads, and electrochemical detection is performed by controlling the flow at the position of the electrode portions. Furthermore, the flow is controlled by a flow rate control pad, a flow passage portion fiber pad, and flow rate control protruding portions.

First claim

The invention claimed is:

1. A method for manufacturing an electrochemical lateral flow immunosensor, wherein:
an electrode portion consisting of a counter electrode obtained by printing a conductive carbon on a supporting body composed of a resin sheet so as to be opposite to a working electrode printed with a conductive carbon, and a reference electrode obtained by printing silver/silver chloride; and a connecting portion connected to an electrical measuring instrument for measuring a value of an electric current are provided on a supporting body composed of a resin sheet; and
a flow passage portion fiber pad is on the supporting body, the flow passage portion fiber pad being configured to transfer an antibody or antigen in a sample solution and an antibody or antigen bonded to a marker composed of metal fine particles toward the working electrode while reacting them;
a flow rate control pad is on the electrode portion, which is connected to the flow passage portion fiber pad and configured to control a flow pattern including a flow rate and/or volume of the sample solution such that a reactant in the sample solution and a capture antibody or antigen immobilized on the working electrode cause an antigen/antibody reaction;
the flow passage portion fiber pad is on the flow rate control pad, or the flow rate control pad is on the electrode portion via the flow passage portion fiber pad, and
flow rate control pad is configured to control the flow pattern including the flow rate and/or volume of the sample solution at a position of the electrode portion and configured to electrochemically detect an amount of the metal fine particles corresponding to an amount of the antigen or antibody in the test substance, wherein the method comprises:
forming, on a supporting body composed of a resin sheet, an electrode portion consisting of a working electrode, a reference electrode and a counter electrode obtained by printing a conductive carbon, an electrically conductive portion transferring electric current of them, and a connecting portion for connecting to an electrical measuring instrument, and furthermore printing silver/silver chloride on the conductive carbon on the counter electrode;
immobilizing an antibody or antigen on a surface of the working electrode; and
placing a flow passage portion fiber pad on the support body, which transfers an antibody or antigen in a sample solution and an antibody or antigen bonded to a marker composed of metal fine particles toward the working electrode while reacting them, and placing a flow rate control pad on the electrode portion, which controls a flow pattern including a flow rate and/or volume of the sample solution such that a reactant in the sample solution and a capture antibody or antigen immobilized on the working electrode cause an antigen/antibody reaction.

2. The method for manufacturing the electrochemical lateral flow immunosensor according to claim 1 , comprising a step of placing, on the supporting body:
a sample pad that absorbs a dripped sample solution;
a conjugation pad that absorbs the sample from the sample pad, and simultaneously dissolves an antibody or antigen bonded to the marker composed of a gold colloid infiltrated in the pad and dried, thereby conjugating the sample with the antibody or antigen;
the flow passage portion fiber pad that transfers the antibody or antigen in the sample and the antibody or antigen bonded to the gold colloid toward the working electrode while reacting them;
the flow rate control pad that causes an antigen/antibody reaction of a transferred reactant with the capture antibody or antigen immobilized on the working electrode to complete formation of a sandwich structure; and
the absorption pad that absorbs a reaction residue liquid of the sample solution.

3. The method for manufacturing the electrochemical lateral flow immunosensor according to claim 1 , wherein:
the electrochemical lateral flow immunosensor further comprises a sample pad, a conjugation pad, and an absorption pad as pads:
a downstream part of the sample pad is laminated onto a part of an upstream upper face of the conjugation pad, and a lower face of the sample pad is fixed with an adhesive on the support body;
a downstream part of the conjugation pad is laminated onto a part of an upper face of the flow passage portion fiber pad, and a lower face of the conjugation pad is fixed with the adhesive on the support body;
a working electrode/counter electrode/reference electrode part, which is a downstream part, of the flow passage portion fiber pad is laminated onto a part of an upstream upper face, and a lower face of the flow passage portion fiber pad is fixed with the adhesive on the support body;
an upstream part of the flow rate control pad is laminated onto a part of a downstream upper face of the flow passage portion fiber pad, and a lower face of the flow rate control pad is brought into close contact with (but not fixed with the adhesive to) the three electrodes, i.e., the working electrode, the counter electrode, and the reference electrode; and
the absorption pad is laminated onto a part of an upstream lower face of the flow rate control pad, and a lower face of the absorption pad is fixed with the adhesive on the support body.

4. The method for manufacturing the electrochemical lateral flow immunosensor according to claim 3 , wherein:
the upstream part of the flow rate control pad is laminated onto a part of the lower face of the flow passage portion fiber pad, and the lower face of the flow rate control pad is brought into close contact with (but not fixed with the adhesive to) the three electrodes, i.e., the working electrode, the counter electrode, and the reference electrode; and
a part of an upstream lower face of the absorption pad is laminated onto a downstream upper face of the flow rate control pad.

5. The method for manufacturing the electrochemical lateral flow immunosensor according to claim 1 , wherein:
the upstream part of the flow rate control pad is laminated onto a part of the lower face of the flow passage portion fiber pad, and the lower face of the flow rate control pad is brought into close contact with (but not fixed with an adhesive to) the three electrodes, i.e., the working electrode, the counter electrode, and the reference electrode; and
a part of an upstream lower face of the absorption pad is laminated onto a downstream upper face of the flow rate control pad.

6. An electrochemical lateral flow immunological test method, wherein:
an electrode portion obtained by printing a conductive carbon, an electrically conductive portion obtained by printing conductive carbon transferring electric current from the electrode portion, and a connecting portion connected to an electrical measuring instrument for measuring a value of the electric current, are provided on a supporting body composed of a resin sheet;
a flow passage portion fiber pad is provided on the supporting body, which transfers an antibody or antigen in a sample solution and an antibody or antigen bonded to a marker composed of metal fine particles toward the electrode portion while reacting them;
a flow rate control pad is provided on the electrode portion, which is connected to the flow passage portion fiber pad and controls a flow pattern including a flow rate and/or volume of the sample solution such that a reactant in the sample solution and a capture antibody or antigen immobilized on the electrode portion cause an antigen/antibody reaction;
the flow passage portion fiber pad is on the flow rate control pad, or the flow rate control pad is on the electrode portion via the flow passage portion fiber pad, and
while the sample solution as a test substance containing the antigen or antibody and the metal fine particles to which the

Assignees

• Immunosens Co Ltd
• Univ Osaka

Inventors

• Tamiya Eiichi
• Shimizu Takenori
• Yamada Shigeki

Classifications

• G01N27/48

  using polarography, i.e. measuring changes in current under a slowly-varying voltage · CPC title

• G01N27/327

  Biochemical electrodes {, e.g. electrical or mechanical details for in vitro measurements} · CPC title

• B01L2400/086

  using baffles or other fixed flow obstructions · CPC title

• B01L2400/08

  Regulating or influencing the flow resistance · CPC title

• B01L2300/0825

  Test strips · CPC title