ELECTRODE FOR ENZYMATIC BIOSENSOR WITH FIBROUS MATERIAL, METHOD OF PREPARATION THEREOF AND SAID BIOSENSOR

Abstract

An electrode for enzymatic biosensor being in the form of a fibrous material and comprising electrically conductive fibres and electrically non-conductive fibres, all or part of which are functionalised by enzymes, identical or different. A method for preparing such an electrode and an electrochemical detection enzymatic biosensor comprising same.

Claims

1. An electrode for enzymatic biosensor being in the form of a fibrous material and comprising electrically conductive fibres and electrically non-conductive fibres, all or part of which are functionalised by enzymes, identical or different.

2. The electrode according to claim 1, wherein the electrode comprises electrically conductive fibres, a first type of electrically non-conductive fibres, non-functionalised by enzymes and at least one second type of electrically non-conductive fibres, different from the first type of electrically non-conductive fibres, all or part of which are functionalised by enzymes, identical or different.

3. The electrode according to claim 1, wherein the electrode is in the form of a fibrous material, compressible and resilient.

4. The electrode according to claim 3, wherein said fibrous material is in the form of a woven textile, in the form of a knitted textile or in the form of a non-woven textile.

5. The electrode according to claim 1, wherein said electrically conductive fibres are chosen from the group consisting of metal fibres, carbon fibres, fibres made of electrically conductive polymers or copolymers, fibres made of conductive polymer composites (CPC) and fibres made to be conductive via coating or metallisation.

6. The electrode according to claim 1, wherein said enzymes are chosen from the group consisting of oxidoreductases, oxygenases, peroxidases, catalases, transhydrogenases, dehydrogenases, transferases, hydrolases, lyases and ligases.

7. The electrode according to claim 1, wherein said functionalisation of the electrically non-conductive fibres by enzymes is direct or indirect.

8. A method for preparing an electrode for enzymatic biosensor according to claim 1, said method comprising: a1) functionalisation of the electrically non-conductive fibres by enzymes; b1) mixing of the electrically non-conductive fibres functionalised by enzymes with other fibres chosen from the group consisting of electrically conductive fibres, electrically non-conductive fibres and one of the mixtures thereof; and c1) shaping of the mixture of fibres obtained at step b1) so as to obtain a fibrous material.

9. A method for preparing an electrode for enzymatic biosensor according to claim 1, said method comprising: a2) functionalisation of the electrically non-conductive fibres by reactive functions; b2) mixing of the electrically non-conductive fibres functionalised by reactive functions with other fibres chosen from the group consisting of electrically conductive fibres, electrically non-conductive fibres and one of the mixtures thereof; and c2) shaping of the mixture of fibres obtained at step b2) so as to obtain a fibrous material; the functionalisation by enzymes of the electrically non-conductive fibres functionalised beforehand by reactive functions being carried out either after step b2) and prior to step c2), or after step c2).

10. A method for preparing an electrode for enzymatic biosensor according to claim 1, said method comprising: a3) mixing of the electrically conductive fibres and electrically non-conductive fibres, and b3) shaping of the mixture of fibres obtained at step a3) so as to obtain a fibrous material, the functionalisation by enzymes of the electrically non-conductive fibres being carried out either after step a3) and prior to step b3), or after step b3).

11. The method according to claim 8, wherein when the fibrous material is non-woven, the shaping during said step c1) is carried out using a dry technique such as the carding method or the airlaid method.

12. The method according to claim 9, wherein when the fibrous material is non-woven, the shaping during said step c2) is carried out using a dry technique such as the carding method or the airlaid method.

13. The method according to claim 10, wherein when the fibrous material is non-woven, the shaping during said step b3) is carried out using a dry technique such as the carding method or the airlaid method.

14. Method according to claim 8, wherein the fibrous material obtained following said step c1) is subjected to a consolidation.

15. Method according to claim 9, wherein the fibrous material obtained following said step c2) is subjected to a consolidation.

16. Method according to claim 10, wherein the fibrous material obtained following said step b3) is subjected to a consolidation.

17. Electrochemical detection enzymatic biosensor, comprising an electrode according to claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0113] FIG. 1 is a schematic representation of the method for preparing an electrode such as defined in the fourth embodiment according to the invention, said method being such as defined in the first alternative of the method according to the invention.

[0114] FIG. 2 is a schematic representation of the method for preparing an electrode such as defined in the fourth embodiment according to the invention, said method being such as defined in the second alternative of the method according to the invention.

[0115] FIG. 3 is a schematic representation of the method for preparing an electrode such as defined in the fourth embodiment according to the invention, said method being such as defined in the third alternative of the method according to the invention.

DESCRIPTION OF EMBODIMENTS

[0116] Electrode for Enzymatic Biosensor According to the Invention.

[0117] The electrode according to the invention is a non-woven material and comprises: [0118] electrically conductive fibres which are carbon fibres of diameter between 4 μm and 8 μm typically derived from multifilament based on polyacrylonitrile (PAN), [0119] electrically non-conductive and enzyme-bearing fibres which are PET fibres of yarn count comprised between 0.3 dTex and 17 dTex and notably between, 0.5 dTex and 2 dTex on which are fixed, in a covalent manner, enzymes of oxidoreductases, glucose oxidases type, and [0120] resilient fibres which are low melting point fibres, such as for example LowMelt two-component PET/coPET fibres, having a yarn count ranging from 2 dTex to 12 dTex.

[0121] In this electrode, the ratio of the fibres implemented is between 50% and 80% of carbon fibres, between 10% and 50% of enzyme-bearing fibres, and between 10% and 30% of resilient fibres.

[0122] The fibres are interlaced with each other with contact zones where the electrically conductive fibres are in contact with each other and with the enzyme bearing fibres and other zones where the fibres are separated from each other.

[0123] II. Method for Preparing the Electrode According to the First Alternative.

[0124] In this method of which the principle is shown schematically in FIG. 1, the electrically non-conductive fibres which are the PET fibres are functionalised beforehand by enzymes of the glucose oxidase type.

[0125] This functionalisation firstly consists in subjecting the fibres to a surface oxidation generating —OH or —COOH polar functions on the surface of the fibres then enzymes of glucose oxidase type are chemically grafted onto the fibres via peptide bonds (activated ester and creation of amide bonds, esterification, etc.).

[0126] The fibres thus functionalised are next mixed with the carbon fibres and LowMelt two-component PET/coPET resilient fibres.

[0127] In order to create the non-woven material, the airlaid technique is used. To do so, the fibres of the mixture of fibres are opened then inserted into the apparatus where they are mixed by air current in order to obtain a non-woven having a homogeneous distribution of fibres. On coming out, a controlled part of the mixture of fibres is deposited by air on a carpet thus forming the web of mass per unit area between 100 g/m.sup.2 and 800 g/m.sup.2, notably between 200 g/m.sup.2 and 300 g/m.sup.2.

[0128] This web is next consolidated. The consolidation technique used is thermal bonding preferably in an oven. The fibrous material thus obtained plays the role of working electrode (WE) thanks to the electrically conductive fibres that it contains. As counter-electrode (CE) it is possible to use a platinum grid, a platinum wire, a titanium platinum plate, a paste of carbon black and activated carbon encapsulated in a stainless steel grid or a paste of carbon black, activated carbon and Teflon encapsulated in a stainless steel grid. As reference electrode (RE), it is possible to use a saturated calomel electrode such as a calomel electrode saturated with potassium chloride or sodium chloride, an Ag/AgCl electrode or instead a platinum wire.

[0129] III. Method for Preparing the Electrode According to the Second Alternative.

[0130] In this method of which the principle is shown schematically in FIG. 2, the PET fibres are subjected to a surface oxidation generating —OH or —COOH polar functions on the surface of the fibres then the fibres thus pre-functionalised PET fibres are mixed with the carbon fibres and the resilient LowMelt two-component PET/coPET fibres.

[0131] The mixture thus obtained is subjected to the airlaid technique as described for the method of point II above.

[0132] Once the web has been obtained, it is brought into contact with enzymes of glucose oxidase type and subjected to conditions enabling the chemical fixation of these enzymes on the pre-functionalised PET fibres contained in the web via peptide bonds (activated ester and creation of amide bonds, esterification, etc.).

[0133] The remainder of the method, namely the consolidation, is identical to that described for the method of point II above.

[0134] IV. Method for Preparing the Electrode According to the Third Alternative.

[0135] In this third alternative of which the principle is shown schematically in FIG. 3, the PET fibres, the carbon fibres and the resilient LowMelt two-component PET/coPET fibres are all mixed together.

[0136] The mixture thus obtained is subjected to the airlaid technique as described for the method of point II above.

[0137] Once the web has been obtained, it is placed in contact with enzymes of glucose oxidase type and subjected to conditions enabling the chemical fixation of these enzymes on the PET fibres contained in the web via covalent bonds.

[0138] The remainder of the method, namely the consolidation, is identical to that described for the method of point II above.