Method for determining an analyte content of a liquid sample by means of a bioanalyzer

Patent metadata

Field	Value
Publication number	US-10036098-B2
Application number	US-201113881658-A
Country	US
Kind code	B2
Filing date	Aug 26, 2011
Priority date	Oct 29, 2010
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A method for automated in situ determining an analyte content of a liquid sample by means of a bioanalyzer, wherein a measurement duct has at least one substrate, comprising a repeatedly performable sequence of steps as follows: (i) preparing a sensor matrix, which has a plurality of receptors, which bind the analyte and/or a further target molecule, or bring about a chemical conversion of the analyte or of the further target molecule, leading through the measurement duct a preparation solution of at least a first chemical species, wherein a plurality of the first chemical species are bound on the substrate via the functional group binding on the substrate, wherein the other functional group of the plurality of the first chemical species bound on the substrate serves as a receptor or for subsequent binding of a receptor; (ii) leading the liquid sample, through the measurement duct, wherein analyte contained in the liquid sample or in the liquid to be measured, and/or other target molecules contained in the liquid sample or the liquid to be measured, bind, preferably selectively and specifically, on the receptors or are chemically converted by the receptors, and determining a measured variable correlated with the amount of the target molecules bound or converted by the receptors, and deriving therefrom the analyte content of the liquid sample; and (iii) regenerating, especially clearing, the at least one substrate, wherein the sensor matrix and, in given cases, molecules bound thereto, especially analyte molecules, other target molecules or other molecules, are released from the substrate and/or at least partially decomposed.

First claim

The invention claimed is:

1. A method for automated in situ determining of an analyte content of a liquid sample using a bioanalyzer, the method comprising a repeatedly performable sequence of steps as follows:
(i) preparing a sensor matrix said sensor matrix comprising a plurality of receptors, which form a terminating receptor layer of said sensor matrix and which bind the analyte and/or further target molecules, or bring about a chemical conversion of the analyte or of the further target molecules, wherein said preparing of the sensor matrix includes leading through a measurement duct of a microfluidic system of the bioanalyzer a preparation solution of at least a first chemical species, which include at least one first functional group binding on a substrate of the measurement duct and at least one second functional group, wherein an amount of the first chemical species of the preparation solution are bound on the substrate via the at least one first functional group binding on the substrate, and wherein the at least one second functional group of the amount of the first chemical species bound on the substrate serves as said plurality of receptors or for subsequent binding of said plurality of receptors;
(ii) leading the liquid sample, or a liquid to be measured obtained by treating the liquid sample with at least one reagent, through the measurement duct, wherein the analyte contained in the liquid sample or in the liquid to be measured, and/or the further target molecules contained in the liquid sample or the liquid to be measured, binds on the plurality of receptors or are chemically converted by the plurality of receptors, and determining a measured variable correlated with the amount of the further target molecules bound or converted by the plurality of receptors or with the amount of the analyte bound or converted by the plurality of receptors and deriving therefrom the analyte content of the liquid sample; and
(iii) clearing the substrate, wherein the clearing includes continuously leading an aqueous electrolyte through the measurement duct and effecting an electrical current flow between the substrate and a counter electrode through the aqueous electrolyte,
wherein the effecting of the current flow includes, during the leading of the aqueous electrolyte through the measurement duct, controlling an electrical potential of the substrate alternately between negative values of −0.5 V to −1.25 V and positive values of +1.5 V to +2.25 V relative to an Ag/AgCl-reference electrode, such that the sensor matrix is alternately exposed to oxidizing and reducing conditions yielding oxygen and hydrogen formation, respectively, whereby the sensor matrix, including the analyte and any of the further target molecules bound thereto, are released from the substrate, wherein the substrate comprises a metal material.

2. The method as claimed in claim 1 , wherein the counter electrode is embodied in the measurement duct opposite to the substrate or coaxially with the substrate, as another substrate, on which binds the functional group of the first chemical species binding on the substrate.

3. The method as claimed in claim 1 , wherein the substrate comprises a thiophilic, electrically conductive substrate and the functional group of the first chemical species binding on the substrate comprises a thiol, or disulfide, group, wherein a layer of the first chemical species is formed by binding of the sulfur atoms of the thiol, or disulfide, groups on the substrate.

4. The method according to claim 1 , wherein during the electrical current flow, electrically conductive contact between the substrate and the counter electrode is established by the aqueous electrolyte, which contains cyanide ions or halogen ions in concentrations of less than 150 mmol/l.

5. The method as claimed in claim 1 , wherein the potential of the substrate is varied continuously or discontinuously between a minimum value and a maximum value, in order to reclear the substrate by electrochemical cleaning, and/or the electrical current level of the electrical current flow produced between the substrate and the counter electrode is varied continuously or discontinuously, between a minimum value and a maximum value, in order to reclear the substrate by electrochemical cleaning.

6. The method as claimed in claim 1 , wherein one or more cleaning liquids and/or one or more auxiliary liquids is/are led through the measurement duct, before, during or after the producing of the electrical current flow between the substrate and the counter electrode.

7. The method as claimed in claim 6 , wherein during the effecting of the electrical current flow between the substrate and the counter electrode, an acidic phosphate buffer solution is led as the aqueous electrolyte through the measurement duct, the aqueous electrolyte including Na 2 SO 4 or H 2 O 2 .

8. The method as claimed in claim 7 , wherein the acidic phosphate buffer solution includes a peroxide.

9. The method as claimed in claim 1 , wherein the sequence of steps (i)-(iii) are performed in situ repeatedly and directly one after the other at least 50 times.

10. The method as claimed in claim 1 , the method further comprising:
during or following the clearing, checking the substrate for residual components of the sensor matrix by means of an electrochemical measuring method, an optical measuring method or an adsorption test, or by measuring electrical current level during the clearing.

11. The method as claimed in claim 1 , wherein during the leading of the liquid sample or the liquid to be measured obtained by treating the liquid sample with at least one reagent through the measurement duct, the analyte contained in the liquid sample, or in the liquid to be measured and/or other target molecules contained in the liquid sample or the liquid to be measured, binds selectively and specifically on the plurality of receptors.

12. The method as claimed in claim 1 , wherein the Ag/AgCl-reference electrode is in conductive contact via the aqueous electrolyte via an electrolyte bridge.

13. The method as claimed in claim 1 , wherein the electrical potential of the substrate in reference to a reference potential is varied linearly between a minimum value and a maximum value.

14. The method as claimed in claim 1 , wherein the sensor matrix comprises a receptor layer including the plurality of first chemical species bound on the substrate via their first functional group and the second functional group of said plurality of first chemical species bound on the substrate serving as said plurality of receptors.

15. The method as claimed in claim 1 , wherein the sensor matrix further includes one or a plurality of binding layers, wherein the plurality of first chemical species bound on the substrate via their first functional group forms a first binding layer, and
wherein the preparing of the sensor matrix further comprises, after the leading through the measurement duct of said preparation solution of the first chemical species and passing through the measurement duct an additional preparation solution, or several additional preparation solutions sequentially, each additional preparation solution including chemical species forming an additional binding layer of the sensor matrix, and binding the plurality of receptors on an outermost binding layer of the sensor matrix to form the terminating receptor layer.

16. The method as claimed in claim 1 , where in the metal material is gold and/or platinum.

Assignees

• Hanko Michael
• Eubisch Angela
• Fikus Axel
• Endress Hauser Conducta Gmbh Co Kg

Inventors

• Hanko Michael
• Eubisch Angela
• Fikus Axel

Classifications

• G01N33/5438

  Electrodes · CPC title

• C25F1/00 Primary

  Electrolytic cleaning, degreasing, pickling or descaling · CPC title

• G01N33/56983

  Viruses · CPC title

• G01N33/54306

  Solid-phase reaction mechanisms · CPC title

• G01N33/52

  Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper {and including single- and multilayer analytical elements (immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72)} · CPC title