Galactose-deficient immunoglobulin A1 electrochemical biosensor

Abstract

An electrochemical biosensor for galactose-deficient immunoglobulin A1 (Gd-IgA1) is disclosed for detecting several Gd-IgA1 molecules in a liquid sample. The sensor comprises a substrate, an introduction pad, a conjugate pad, a test area, and a measuring element. The introduction pad guides the liquid sample along the detection direction. The test area includes a porous membrane and an electrode. A conductive layer and a biorecognition layer are formed on the electrode. The biorecognition layer has a binding sublayer containing several antibodies and lectins for binding to the Gd-IgA1 molecules, and a fixation sublayer located below the binding sublayer. The conductive layer conducts the electrical signals generated when the lectins and antibodies bind to Gd-IgA1 molecules. Under the measurement of the measuring element, the magnitude of the current is used to determine the risk of IgA nephropathy in the subject.

Claims

1. An electrochemical biosensor for galactose-deficient immunoglobulin A1 (Gd-IgA1) in a liquid sample, comprising: a substrate extending along a detection direction; an introductory pad disposed above the substrate and adapted to receive the liquid sample and allow the liquid sample to move along the detection direction; and a conjugate pad disposed above the substrate and downstream of the introductory pad along the detection direction, containing a plurality of lectins for binding with the Gd-IgA1 in the liquid sample to form a plurality of lectin-Gd-IgA1 complexes; An inspection area, disposed above the base plate and downstream of the conjugate pad along the detection direction, includes a porous membrane for transferring the liquid sample, and an electrode disposed below the porous membrane. A conductive layer is formed on the electrode, and a biometric layer is located above the conductive layer. The biometric layer has a binding sublayer containing the lectin and several antibodies for binding with the Gd-IgA1 to form several antibody-Gd-IgA1 complexes, and an immobilization sublayer located below the binding sublayer for immobilizing the lectin-Gd-IgA1 complexes and the antibody-Gd-IgA1 complexes. The conductive layer conducts the electrical signals generated during the formation of the lectin-Gd-IgA1 complexes and the antibody-Gd-IgA1 complexes. A measuring element is connected to the electrode in the inspection area to receive and measure the electrical signals.

2. The galactose-deficient immunoglobulin A1 electrochemical biosensor as claimed in claim 1 further includes an absorbent pad disposed above the base plate and downstream of the test area along the detection direction for absorbing any remaining liquid sample.

3. The electrochemical biosensor for galactose-deficient immunoglobulin A1 as described in claim 1, wherein, The electrode has a working electrode portion containing the conductive layer and the biometric layer, a reference electrode portion connected to the working electrode portion along the detection direction and used to provide a standard potential, and an auxiliary electrode portion connected to the reference electrode portion along the detection direction and used to share the current.

4. The electrochemical biosensor for galactose-deficient immunoglobulin A1 as described in claim 1, wherein, The conductive layer has a first conductive layer made of MXene and a second conductive layer located above the first conductive layer. The material of the second conductive layer is selected from the group consisting of graphene, graphene oxide, reduced graphene oxide, and carbon nanotubes.

5. The galactose-deficient immunoglobulin A1 electrochemical biosensor as described in claim 1, wherein, These antibodies are KM55 antibodies.

6. The electrochemical biosensor for galactose-deficient immunoglobulin A1 as described in claim 1, wherein, The porous membrane is a nitrocellulose membrane.

7. The galactose-deficient immunoglobulin A1 electrochemical biosensor as described in claim 1, wherein, The fixed sublayer of this bio-identification layer is composed of several nano-metal particles.

8. The galactose-deficient immunoglobulin A1 electrochemical biosensor as described in claim 7, wherein the nanometal particles are selected from the group consisting of gold, silver, platinum, gold-silver alloys, gold-platinum alloys, silver-platinum alloys, and gold-silver-platinum alloys.

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