FR3063918A1 - DEVICE AND METHOD FOR QUICKLY TESTING A LIQUID SAMPLE - Google Patents

Abstract

The rapid test device (1) comprises: a fabric (5) woven integrally with longitudinal and transverse yarns, the fabric (5) comprising an application zone (7) of a liquid sample (3) to be tested and an impregnation zone (11) of the liquid sample (3), which extends from the application zone (7), the impregnation zone (11) being configured to be impregnated by the liquid sample (3) by applying said liquid sample (3) to the application zone (7); and rapid test means (15, 16) of the liquid sample (3) disposed in the impregnation zone (11). According to the invention, at least in the impregnation zone (11), to direct the impregnation of the fabric (5) by the liquid sample (3) along the longitudinal threads: - more than the majority of the longitudinal threads of the fabric (5) are hydrophilic, and - most of the transverse threads of the fabric (5) are hydrophobic.

Description

® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number: 3,063,918 (to be used only for reproduction orders) © National registration number: 17,52211

COURBEVOIE © Int Cl ⁸ : B 01 L 3/00 (2017.01), G 01 N 33/543, D 03 D 15/00

A1 PATENT APPLICATION

©) Date of filing: 17.03.17. © Applicant (s): PORCHER INDUSTRIES Company (© Priority: anonymous— FR. @ Inventor (s): CONESA ISABELLE and DA SILVA JOAQUIM. (43) Date of public availability of the request: 21.09.18 Bulletin 18/38. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): PORCHER INDUSTRIES Société ano- related: nyme. ©) Extension request (s): (© Agent (s): LAVOIX.

DEVICE AND METHOD FOR RAPID TESTING OF A LIQUID SAMPLE.

FR 3 063 918 - A1

This rapid test device (1) comprises: a fabric (5) woven in one piece with longitudinal and transverse threads, the fabric (5) comprising an application area (7) of a liquid sample (3) to be tested and an impregnation zone (11) of the liquid sample (3), which extends from the application zone (7), the impregnation zone (11) being configured to be impregnated with the liquid sample (3) by applying said liquid sample (3) to the application area (7); and rapid test means (15, 16) of the liquid sample (3) arranged in the impregnation zone (11).

According to the invention, at least in the impregnation zone (11), to direct the impregnation of the fabric (5) by the liquid sample (3) along the longitudinal wires:

more than the majority of the longitudinal threads of the fabric (5) are hydrophilic, and

- more than the majority of the transverse threads of the fabric (5) are hydrophobic.

Device and method for rapid testing of a liquid sample

The present invention relates to a rapid test device for a liquid sample, as well as a method for rapid test of a liquid sample, implemented using such a device.

More particularly, the invention relates to the field of rapid test devices, in particular immunochromatography (or "lateral flow") tests, making it possible to detect the possible presence of one or more predetermined elements in a liquid sample, by example of physiological origin, such as blood, plasma, serum, urine, or even of food origin, by depositing this liquid sample on a deposit area of the device. This type of device is generally designed to quickly indicate or quantify the presence of a predetermined element in the liquid sample, using an indicator, in particular a visual indicator, after diffusion of the liquid sample onto and / or into the support. To ensure this diffusion, the device generally comprises a nitrocellulose strip.

WO-2005/098439 A1 describes a test strip for the detection of an analyte present in a liquid sample applied to the strip. The strip comprises a single hydrophilic matrix, including a network of fibers and a series of zones, namely a zone of application of the sample; a conjugation zone including a labeled binding reagent, which is able to bind specifically to the analyte sought and to progress along the strip when the binding is made; and a capture reagent capable of binding to the analyte sought or to the labeled binding reagent.

FR-2 781 056 A1 describes a wiping test strip for detecting substances, comprising similar means. In particular, this test strip comprises a zone for taking the sample by wiping consisting of all types of fibrous and / or porous materials, such as glass, polyester or cellulose fibers. FR-2 781 056 provides in particular that this zone can be made of polyester fiber fabric.

However, in these known strips, the impregnation is carried out omnidirectionally, so that part of the liquid sample is propagated in regions of the strip which are not necessarily useful for the analysis.

US-2010/0172798 A1 describes a test pad including a polymer tissue, in which the impregnation of a liquid sample is carried out perpendicular to the plane of the tissue for the analysis of body fluids. The tissue includes regions made hydrophobic by irradiation to define and guide the propagation of the liquid sample in the tissue.

On the other hand, the methods for rendering hydrophobic fabrics can prove to be relatively expensive and difficult to implement for certain particular applications, in particular in the case where the fabric comprises glass strands.

The invention therefore aims to remedy these drawbacks by proposing a new rapid test device which, while being inexpensive, easy to manufacture, and adaptable to multiple applications, makes it possible to carry out a rapid test effectively.

The subject of the invention is a device for rapid testing of a liquid sample, the device comprising:

a woven fabric in one piece with longitudinal threads and transverse threads, the fabric comprising an area for applying the liquid sample to be tested and an area for impregnating the liquid sample, which extends to starting from the application area, the impregnation area being configured to be impregnated with the liquid sample by applying said liquid sample to the application area; and

- means for rapid testing of the liquid sample placed in the impregnation area.

According to the invention, at least in the impregnation zone, to direct the impregnation of the tissue by the liquid sample along the longitudinal threads:

more than the majority, preferably all, of the longitudinal threads of the fabric are hydrophilic, and

more than the majority, preferably all, of the transverse threads of the fabric are hydrophobic.

Thanks to the invention, the impregnation of the fabric with the liquid sample is carried out mainly, or even only, in the direction of the longitudinal threads of the fabric. Nevertheless, the fabric is relatively easy to manufacture, insofar as the individually hydrophobic or hydrophilic nature of the threads used suffices to direct, that is to say channel, the impregnation of the fabric with the liquid sample, advantageously without using additional tissue treatments, such as irradiation.

Other advantageous characteristics of the invention, taken alone or in combination:

At least in the impregnation zone: the longitudinal hydrophilic threads are threads of which at least the external surface is made of inorganic material, of the glass type, and the hydrophobic transverse threads are threads of which at least the external surface is made of organic material, like plastic.

The inorganic material is glass and the organic material is a plastic, comprising for example at least one of the following polymers: polyamide, polyester, polyvinyl chloride or polypropylene.

At least in the impregnation zone, the fabric has a density of transverse threads less than the density of longitudinal threads, the density of transverse threads being measured in a longitudinal direction of the fabric defined by the longitudinal threads, and the density of longitudinal threads being measured in a transverse direction of the fabric defined by the transverse threads.

At least in the impregnation area, the density of transverse threads is at least half as much as the density of longitudinal threads.

At least in the impregnation zone, the density of transverse threads is less than 10 threads / cm, preferably about 3 threads / cm, and the density of longitudinal threads is worth more than 10 threads / cm, preferably more than 30 threads / cm.

The rapid test means comprise at least one reagent immobilized on and / or in the tissue, in the impregnation zone, this immobilized reagent being for example an antibody, an antigen, or a protein.

The device comprises a rigid support on or in which the fabric is placed.

The invention also relates to a method for rapid testing of a liquid sample, the method comprising:

- a step of applying a liquid sample to the application area of a device in accordance with the above, and

a step of impregnation, by the liquid sample, of the tissue of the device, step in which the liquid sample propagates along the impregnation zone while being directed along the longitudinal wires, so as to reach the means rapid device test.

The invention will be better understood with the aid of the description which follows, given solely by way of nonlimiting illustration, and with reference to the appended FIG. 1, being a schematic perspective view of a rapid test device conforming to the invention. 'invention.

FIG. 1 illustrates a rapid test device 1 for a liquid sample 3. The device 1 is used to determine whether the sample 3 contains an element, that is to say a particular predetermined analyte. Preferably, the device 1 is designed for testing a predetermined type of sample 3. The sample 3 to be tested is for example a body fluid, of the blood, urine, saliva, or other type. Alternatively, the sample 3 to be tested is any liquid substance, body or not, in which it is desired to detect the possible presence of an analyte. For example, sample 3 can be a food substance. Depending on the application, it can be chosen that the analyte detected by the device 1 is, for example, of the bacteria, virus, protein, antigen, antibody, enzyme, drug, pollutant type contained in the sample 3.

The device 1 comprises a fabric 5, which is woven in one piece with longitudinal threads, defining a longitudinal direction X of the fabric 5, and transverse threads, defining a transverse direction Y of the fabric 5. By “fabric”, it is understood that the longitudinal threads and the transverse threads are interlaced according to a weaving weave, obtained for example using a weaving loom. By "in one piece" is meant that the fabric is formed in a single weaving step. The directions X and Y are preferably perpendicular and extend in the plane of the fabric 5. The longitudinal threads are preferably warp threads, while the transverse threads are preferably weft threads. It can however be provided that the longitudinal threads are weft threads and that the transverse threads are warp threads.

A thickness direction Z of the fabric 5 is also defined, directed perpendicular to the directions X and Y, that is to say in the direction of the thickness of the fabric 5.

In the present example, the fabric 5 has an elongated shape in the direction X. More specifically, the fabric 5 is rectangular, with a long length in the direction X, and a narrower width in the direction Y.

As illustrated in FIG. 1, the fabric 5 comprises an application area 7 of the sample 3, symbolically delimited symbolically by a broken line 10 in FIG. 5. This area 7 corresponds to a part of the fabric 5 located at one end 9 of the fabric 5, in consideration of the direction X. This zone 7 is dedicated to the application of the sample 3 to the fabric 5. This application is for example carried out by depositing a drop of the sample 3 on one side 8 of the fabric, at the level of the area 7. The fabric 5 can however be provided for other application methods, such as wiping or soaking the area 7 of the fabric 5 on or in the sample 3. It is also possible to have a sample pad made of porous or filtering material at the top of zone 7, on which the sample will be deposited before passing through it to reach the underlying tissue.

The fabric 5 also includes an impregnation zone 11 of the sample 3, which can also be called diffusion zone. This zone 11 is adjacent to zone 7, that is to say that it extends from zone 7. Zone 11 extends from the broken line 10. Preferably, zone 11 extends up to one end 13 of the fabric 5, opposite the end 9, in consideration of the direction X.

The fabric 5 having a porous structure, preferably in zones 7 and 11, the liquid sample 3 deposited on the fabric 5 at the level of zone 7 permeates the fabric 5, that is to say propagates in the fabric 5 along zone 11.

In this zone 11, a sufficient number of hydrophilic longitudinal threads and hydrophobic transverse threads are provided to direct the impregnation of the tissue by the liquid sample in the direction X. By "hydrophilic thread" and "hydrophobic thread" is meant the hydrophobicity and the individual hydrophilicity of each thread concerned. Thus, the area 11 of the fabric 5 is rather hydrophilic in the longitudinal direction X, and rather hydrophobic in the transverse direction Y, by arrangement of individually hydrophilic threads and individually hydrophobic threads distributed in these directions X and Y.

Consequently, the individually hydrophilic or hydrophobic nature of the threads of the fabric 5 serves to direct, that is to say channel, the impregnation of the fabric by the sample 3 in the X direction rather than in the Y direction. , the liquid sample tends to impregnate as a priority along the hydrophilic longitudinal threads, without spreading too much along the hydrophobic transverse threads. The sample having been applied in zone 7 and reaching zone 11, at the level of line 10, then propagates in zone 11, mainly, or even completely, in the direction X. Sample 3 propagates little, or not , in direction Y, or in a direction opposite to direction Y. It does not matter whether the sample 3 propagates or not in direction Z.

It is advantageously provided that, in zone 11, all of the longitudinal threads of the fabric 5 are hydrophilic while all of the transverse threads of the fabric 5 are hydrophobic.

It can be foreseen that, in zone 11, the longitudinal threads have, relative to one another, a different degree of hydrophilicity. It can be foreseen that, in zone 11, the transverse wires have, relative to one another, a different degree of hydrophobicity.

It can be foreseen that, in zone 11, certain longitudinal wires are hydrophobic. In this case, it is expected that the proportion of longitudinal hydrophilic yarns relative to the number of hydrophobic longitudinal yarns is high enough to give a relatively hydrophilic character to all of the longitudinal yarns in zone 11. It is expected that more than the majority of the longitudinal wires are hydrophilic in zone 11. It can be provided that, in zone 11, certain longitudinal wires are hydrophilic. In this case, it is expected that the proportion of hydrophobic transverse threads in relation to the number of hydrophilic transverse threads is high enough to give a relatively hydrophobic character to all of the transverse threads in zone 11. It is expected that more than the majority of the cross wires are hydrophobic in zone 11.

It is also possible to provide, in the same fabric, one or more blocking zones in which the impregnation of the liquid sample is not authorized, or is limited, by providing hydrophobic longitudinal threads and hydrophobic transverse threads, while in another zone of the tissue, known as the "channel zone", the longitudinal threads are hydrophilic to promote and guide the propagation in the longitudinal direction. In particular, several parallel channel zones can be formed, in each of which the longitudinal wires are hydrophilic, the adjacent channel zones being separated by a blocking zone, in which the longitudinal wires are hydrophobic, in order to avoid propagation of the liquid sample transversely from the first channel zone to the second adjacent channel zone. In order to improve this effect, it can be expected that the density of longitudinal wires is greater in the blocking zone than in the channel zone.

To obtain a different degree of hydrophobicity or hydrophilicity between the longitudinal and transverse threads, the material constituting the threads is preferably adapted. In other words, the chemical nature of the wire is one of the parameters likely to determine its hydrophilic or hydrophobic nature. In this case, a hydrophilic material is chosen for the hydrophilic longitudinal wires, and hydrophobic for the hydrophobic transverse wires. Preferably, it is provided that the longitudinal hydrophilic threads are threads made of inorganic material, such as glass, rather hydrophilic, while the hydrophobic transverse threads are threads made of organic material, such as plastic, rather hydrophobic material. . Preferably, the aforementioned plastic material comprises one or more of the following polymers: polyamide, polyester, polyvinyl chloride or polypropylene.

Alternatively, this type of material can be provided only on the outer surface of the wire, that is to say for the skin of the wire, while the core of the wire is made of a different material. Indeed, the hydrophilic or hydrophobic nature of the threads depends in particular on the properties of their external surface. For example, in the case of longitudinal wires, it is possible to provide wires whose external surface comprises a hydrophilic sheath, comprising in particular an inorganic material, while these wires comprise an organic material at the core. For example, in the case of transverse wires, it is possible to provide wires whose external surface comprises a hydrophobic sheath, comprising in particular an organic material, while these wires comprise an inorganic material at heart, such as glass. Thus, at least the external surface of each longitudinal wire is made of hydrophilic material, and at least the external surface of each transverse wire is made of hydrophobic material, at least in zone 11.

Alternatively or in addition, other characteristics specific to the yarns can be modified in order to confer a hydrophilic or hydrophobic character to the yarn. For example, provision may be made to modify the number of filaments constituting the wire concerned in order to vary its degree of hydrophilia or hydrophobia.

It is also possible to carry out a surface treatment on each yarn, prior to weaving, of the corona, plasma or supercritical CO _{2 type} , in order to make it hydrophilic or hydrophobic.

The provisions concerning the presence of hydrophilic and hydrophobic yarns applicable to fabric 5 in zone 11 can be applied in the rest of fabric 5, in particular in zone 7.

By “density of transverse threads”, we mean the number of transverse threads of fabric 5 counted per unit of length, over a distance measured in the direction X. By “density of longitudinal threads”, we mean the number of longitudinal threads of the fabric 5 counted per unit of length, over a distance measured in the direction Y.

In general, it is expected that the area 11 of the fabric 5 has a density of transverse threads less than the density of longitudinal threads. Preferably, in zone 11, the density of transverse wires is at least twice less than the density of longitudinal wires. This difference in thread density makes it possible to direct the sample 3 even more effectively along the direction X. In fact, a reduced quantity of transverse threads prevents the impregnation of the fabric 5 in the direction X. Only a reduced quantity of transverse threads is capable of guiding the impregnation of the fabric 5 in the direction Y, so that the impregnation is carried out completely, or almost entirely, in the direction X.

In the present example, in the impregnation zone 11, the density of transverse threads of the fabric 5 is less than 10 threads / cm (threads per centimeter), preferably around 3 threads / cm. The density of longitudinal threads is higher and is more than 10 threads / cm, preferably more than 30 threads / cm. Experience shows that the density values of the present example are particularly suitable for guiding the impregnation of a sample 3 formed by blood or plasma.

The provisions concerning the density of hydrophilic and hydrophobic yarns applicable to fabric 5 in zone 11 can be applied in the rest of fabric 5, in particular in zone 7.

The device 1 advantageously comprises a rigid support, not shown, on or in which the fabric 5 is arranged. The rigid support can have the function of imparting a certain rigidity to the fabric 5. For example the device can be stretched between two elements of the support, the rest of the fabric not being in contact with the support, or only at distant contact points. one another. The rigid support can also have the function of protecting the fabric 5. For example, the rigid support also forms a box in which the fabric 5 is enclosed or stretched.

The device 1 comprises rapid test means arranged in the zone 11. These means are arranged so as to be reached by the sample 3 during its impregnation in the zone 11. The rapid test means are designed to react with in a certain way in contact with the sample 3, when the sample 3 comprises a predetermined analyte, so as to make it possible to detect that the analyte is actually present in the sample 3. In the absence of the analyte, provision is made that the rapid test means react differently, or do not react.

The rapid test means are known as such. However, their application to a fabric such as fabric 5 is not known. These rapid test means are, for example, immunochromatography means, or immunoprecipitation means. We choose the means according to the analyte that we want to detect in sample 3.

The rapid test means comprise at least one reagent immobilized on and / or in the tissue in a zone 16 extending across the zone 11, in the direction Y, from one edge to the other of the tissue 5. The zone 16 advantageously has the form of a transverse line or strip. Any immobilized reagent commonly used in rapid tests can be used, such as an antibody, an antigen, a protein, etc. Immobilization is also done by the usual means in the field.

For carrying out the test, it is possible to use, as is usual, a synthetic or biological detection conjugate labeled or detectable, such as a labeled antibody, a labeled antigen, an enzyme, a labeled protein, etc. use any conventional marking, for example particulate, colored latex or particles of colloidal gold, for example.

Unless the rapid test means chosen are concentrated in a single continuous zone, the means are distributed in the zone 11, in the direction X, so as to be successively reached by the sample 3 during its impregnation in the zone 11. In the present example, there has been shown a zone 15, in the form of a transverse band, situated between zone 7 and zone 16, and on which the conjugate is placed, for example an antibody.

The antibodies of zone 15 are of a first type, and are capable of binding, preferably in a specific manner, to the analyte to be detected. The antibodies carry gold nanoparticles, or any standard detection reagent. The analyte, if present in sample 3, migrating along zone 11, passes through zone 15 where it binds with the labeled antibodies to form a complex. These antibodies are deposited on the tissue 5 so as to be able to be entrained by the sample 3, during impregnation of the latter in the tissue 5, whether or not these antibodies are bound to analytes of the sample 3.

On the second strip 16, there is an immobilized reagent, for example analyte-specific antigens or antibodies specific for the analyte. They are fixed to the fabric 5 so as not to be entrained by the sample 3 during its impregnation. The immobilized reagents are chosen to capture the complexes formed by the analytes linked to the labeled antibodies originating from zone 15, when the sample 3 reaches band 16 by impregnation. This capture advantageously produces a distinctive color of the tissue 5, linked to the presence of the gold nanoparticles or of another colored or detectable marking (fluorescence, enzymatic reaction, as is known).

Of course, the device 1 may include different rapid test means depending on the desired application, as defined above.

It is understood that the device 1 makes it possible to carry out a rapid test of a liquid sample 3. This rapid test includes a step of applying the sample 3 to the zone 7 of the device 1, which follows by a step of impregnation, by the sample 3, of the fabric 5, step in which the sample 3 is propagated along the impregnation zone while being directed along the longitudinal wires. During the impregnation step, the sample 3 successively reaches the rapid test means located in zones 15 and 16.

It is also possible to provide at the end 13, as is the practice in conventional rapid tests, a pad made of very absorbent material intended to facilitate the migration of the sample from the area 7 and through the strips 15 and 16, then accumulate in this buffer. However, the choice of the constituent threads of the fabric according to the invention can make it possible to dispense with such a buffer while ensuring adequate propagation of the sample.

Various tests have been carried out:

Tissue Warp threads Weft threads Deposit of a drop of 18μΙ Spread in direction parallel to the chain Spread in direction parallel to the weft Fabric A 11 tex glass 34 tex glass 10.7 mm 10 mm Fabric B 11 tex glass Polypropylene 10 threads / cm 13.7mm 7 mm Fabric C 11 tex glass Polypropylene 3 threads / cm 22.7 mm 3.6mm Fabric D 11 tex glass Glass coated with PVC 7 threads / cm 16.3 mm 5.6 mm Fabric E 11 tex glass Glass coated with PVC 3 threads / cm 22.7 mm 3.6mm

The drop of 18μΙ is a liquid sample comprising methanol and a dye.

We observe that, for fabric A, the propagation takes place over the same distance in the direction parallel to the warp and parallel to the weft.

For fabrics B to E, the warp threads of which are hydrophilic and the weft threads hydrophobic, it is observed that the propagation is greater in the direction parallel to the warp than in the direction parallel to the weft. We note that this effect is more marked for fabrics C and E, in which the density of weft threads is reduced compared to fabrics B and D.

The characteristics of each variant defined above can be implemented in the other variants described, as far as technically possible.

Claims (9)

1, - Device (1) for rapid testing of a liquid sample (3), the device (1) comprising: - a fabric (5) woven in one piece with longitudinal threads and transverse threads, the fabric (5) comprising an application zone (7) of the liquid sample (3) to be tested and a zone of impregnation (11) of the liquid sample (3), which extends from the application area (7), the impregnation area (11) being configured to be impregnated with the liquid sample (3) by applying said liquid sample (3) to the application area (7); and - rapid test means (15, 16) of the liquid sample (3) arranged in the impregnation zone (11), the device (1) being characterized in that, at least in the impregnation zone ( 11), to direct the impregnation of the fabric (5) by the liquid sample (3) along the longitudinal wires: more than the majority, preferably all, of the longitudinal threads of the fabric (5) are hydrophilic, and - More than the majority, preferably all, of the transverse threads of the fabric (5) are hydrophobic. 2. - Device (1) according to claim 1, characterized in that, at least in the impregnation zone (11): the longitudinal hydrophilic threads are threads of which at least the external surface is made of inorganic material, such as glass, and the hydrophobic transverse threads are threads of which at least the external surface is made of organic material, such as plastic material. 3. - Device (1) according to claim 2, characterized in that the inorganic material is glass and in that the organic material is a plastic material, comprising for example at least one of the following polymers: polyamide, polyester, polyvinyl chloride or polypropylene. 4, - Device (1) according to any one of the preceding claims, characterized in that, at least in the impregnation zone (11), the fabric (5) has a density of transverse threads less than the density of threads longitudinal, the density of transverse threads being measured in a longitudinal direction (X) of the fabric (5) defined by the longitudinal threads, and the density of longitudinal threads being measured in a transverse direction (Y) of the fabric (5) defined by the longitudinal cross wires. 5. - Device (1) according to claim 4, characterized in that, at least in the impregnation zone (11), the density of transverse threads is at least two times less than the density of longitudinal threads. 6. - Device (1) according to claim 5, characterized in that, at least in the impregnation zone (11), the density of transverse threads is less than 10 threads / cm, preferably about 3 threads / cm, and in that the longitudinal thread density is greater than 10 threads / cm, preferably more than 30 threads / cm. 7. - Device (1) according to any one of the preceding claims, characterized in that the rapid test means (15, 16) comprise at least one reagent immobilized on and / or in the tissue (5), in the area impregnation (11), this immobilized reagent being for example an antibody, an antigen, or a protein. 8. - Device (1) according to any one of the preceding claims, characterized in that the device (1) comprises a rigid support on or in which the fabric (5) is arranged. 9. - Method for rapid testing of a liquid sample (3), the method comprising: a step of applying a liquid sample (3) to the application area (7) of a device (1) according to any one of the preceding claims, and - a step of impregnation, by the liquid sample (3), of the fabric (5) of the device (1), step in which the liquid sample (3) propagates along the impregnation zone (11) while being directed along the longitudinal wires, so as to reach the rapid test means (15, 16) of the device (1). 1/1