A cartridge equipped with multiple analytical chambers for receiving biological fluids.

Abstract

The present invention relates to a cartridge (1) for analyzing biological fluids, comprising an array of channels (4, 4') that define a plurality of analysis paths. Each channel is defined by at least two opposing channel walls that define a channel height. According to the present invention, at least one channel wall has a step (M) that defines on either side thereof: a first channel segment (S1), whose walls have a first surface energy (E1) and a first elevation (e1) that defines a first channel height (h1); and a second channel segment (S2), whose walls have a second surface energy (E2) and a second elevation (e2) that defines a second channel height (h2). The first channel height (h1) and the first surface energy (E1) of the walls are greater than the second channel height (h2) and the second surface energy (E2), respectively.

Description

Technical Field

[0001] The technical field of the present invention is the field of biological analysis for detecting the presence and / or concentration of an analyte in a sample of a biological fluid. More particularly, the present invention relates to a cartridge comprising a plurality of analysis chambers for receiving a biological fluid. The cartridge is preferably intended to be used in a portable analyzer of the "point-of-care" type, i.e., to perform and interpret tests at the site, i.e., at the patient's bedside rather than in a central laboratory, to enable immediate clinical decisions. It may also be used in any other type of biological analysis, for example, for molecular biological analysis or cell analysis.

Background Art

[0002] Patent Document 1 discloses a method for capturing and detecting molecules, often referred to as "analytes," in a sample of a biological liquid. The principle for capturing and detecting patterns carried out by this method is also described in a paper by Fratzl et al. (Non-Patent Document 1). According to this method, the sample is mixed with nanometer-sized or more commonly submicrometer-sized magnetic particles, each bound to a capture element capable of binding to the molecule whose presence is to be detected or quantified. The molecule to be detected, i.e., the analyte, may be an antigen, and the above elements may be antibodies, but the reverse configuration is also possible. A detection element, such as a photoluminescence marker or a detection antibody supporting a fluorescent marker, is also introduced into the sample. In solution, a complex formed from the capture element, analyte, and detection element is formed as described above, and this is then immobilized on a support containing a magnetic microsource aligned according to a specific spatial pattern. The above pattern is defined by strong and weak magnetic field zones that induce a considerably large magnetic field gradient. The complex bound by the magnetic particles tends to aggregate on the support in the zone where the magnetic field norm is maximum. Photoluminescent (and especially fluorescent) markers can reveal specific spatial patterns that mark the presence of an analyte in a solution. The average (spatial) intensity of this light pattern is usually called the "specific signal."

[0003] In most cases, especially when the analyte is not present in the sample or its amount is limited, the unbound detection elements that display the photoluminescence marker remain dispersed in the suspension in solution. These contribute to the formation of a relatively homogeneous light background. The average (spatial) intensity of this light background forms a signal called the "supernatant signal." In addition to the unbound photoluminescence marker, this light background is also formed by the intensity of light emitted by all the photoluminescent materials in the sample. Capture elements that are not bound to the analyte and detection elements are also immobilized on the support, but these capture elements do not carry markers. They do not contribute to the light pattern or light background.

[0004] The spatial arrangement of magnetic field microsources on the plane of the support and the light intensity of the pattern exposed by the photoluminescence markers allow for the detection and quantification of analytes in the sample without washing, i.e., without removing the liquid solution after fixing the composite on the surface of the support, which is particularly advantageous. To enable this detection, the surface of the sample and support are irradiated in a way that allows for the detection of the photoluminescence markers, and a digital image is acquired. Thus, this digital image has a spatially variable intensity (within the plane of the image) depending on the strength of the magnetic field generated by the support. By processing the image, it is possible to identify this spatial variation, determine the specific signal and the supernatant signal, and conclude from the specific signal / supernatant signal ratio that the analyte is present in the sample, or even estimate its concentration.

[0005] Traditionally, this type of analysis has been performed in a central laboratory, but the simplicity of the method described above, particularly the absence of a washing step, makes it possible to integrate it into autonomous, portable, or mobile immunoanalytical analyzers that perform analysis "at the patient's bedside" without the need for pumps or valves.

[0006] To enable the application of the detection method, the biological fluid is introduced into a cartridge containing multiple analysis chambers, which is intended to be inserted into the analyzer. The multiple analysis chambers allow for several analyses to be performed on the biological fluid sample, with each analysis being performed independently on the sample held in each chamber.

[0007] The cartridge comprises an injection opening for the liquid, multiple vents located downstream of the analysis chamber, and an array of channels for fluid connection between the opening and the analysis chamber. A sample of biological liquid injected into the opening propagates through the array of channels by capillary action, filling the chamber. However, it has been observed that the propagation of the liquid within the array of channels is not identical across channels. The flow may preferentially occur through certain channels, resulting in liquid overflow from the cartridge. More generally, some chambers may fill more slowly or may not even fill completely. As a result of this phenomenon, analysis may be delayed, or in some cases, it may become impossible to perform analysis in at least some of the analysis chambers of the cartridge.

[0008] Patent Document 2 relates to a microfluidic apparatus and aims to control the fluid flow within the apparatus by combining the displacement of the fluid due to pressure applied by an external pump. More specifically, this document aims to enable the injection and control of multiple fluid flows within an analytical cartridge in several directions. One flow is created by capillary action, and the other is forced by external pressure. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] European Patent No. 3447492 [Patent Document 2] U.S. Patent Application Publication No. 2004 / 028566 [Non-patent literature]

[0010] [Non-Patent Document 1] Fratzl et al., “Magnetophoretic induced convective capture of highly diffusive supermagnetic nanoparticles,” Soft Matter, 14.10.1039 / C7SM02324C [Overview of the project] [Problems that the invention aims to solve]

[0011] Therefore, one object of the present invention is to provide at least a partial solution to this problem. More specifically, one object of the present invention is to provide a cartridge intended for use in a “point-of-care” type portable immunological analyzer, comprising multiple analytical chambers that can be filled by capillary action of biological fluids in a reliable and repeatable manner during a duration-controlled filling period. Therefore, one aim of the present invention is to better control the capillary propagation of biological fluids within the cartridge. Advantageously, immunological analysis is magnetic, and magnetic particles are implemented to mark the presence of analytes in biological fluid samples.

[0012] To achieve this objective, the present invention aims to propose an optical analysis cartridge having a step, as described in claim 1. [Means for solving the problem]

[0013] The claimed features of the stepped structure described above are utilized to control the propagation of biological fluid within the fluid array of the cartridge, and in particular to facilitate the filling of the array chambers with biological fluid in a reliable and repeatable manner during a duration-controlled filling period.

[0014] According to other advantageous non-limiting features of the present invention, either alone or in any technically feasible combination, • A wall facing a structured wall is planar and has a third surface energy greater than the first and second surface energies; • The step has sides, and the surface energy of the side of the step is closer to the first energy than the second energy; The main surfaces of the support and upper cover (7) are hydrophilic; The channel array includes an upstream channel for fluid connection of the opening to the analysis chamber and a vent channel for fluid connection of the analysis chamber to the vent; • The step is located within at least one ventilation channel and tends to reduce the height of this channel in the direction of fluid flow; The analysis cartridge comprises at least one incubation chamber located fluidly upstream of the analysis chamber in the analysis pathway; The analysis chamber and / or incubation chamber shall contain at least one reagent; The reagent contains a photoluminescent marker, and the top cover is formed from a material that is transparent in the wavelength range of the photoluminescent marker, at least in the portion that protrudes into the analysis chamber; The top cover has at least a portion of its outer surface that is optically polished; A reservoir is placed in the opening, and a surrounding wall having a height at least equal to the height of the reservoir is placed in each ventilation opening. The interlayer film is an adhesive film, and more advantageously, a double-sided adhesive film; The magnetic layer includes magnetically polarized regions that define a specific detection pattern.

[0015] In another aspect, the present invention relates to a method for manufacturing an analytical cartridge, comprising providing a support and an upper cover, and assembling the support to the upper cover by positioning their respective main surfaces facing each other, thereby forming opposing walls that define channels. [Brief explanation of the drawing]

[0016] Other features and advantages of the present invention will become apparent from the following detailed description of the invention, with reference to the accompanying drawings.

[0017] [Figure 1a] A cartridge according to the present invention is shown in perspective and exploded views, respectively. [Figure 1b] A cartridge according to the present invention is shown in perspective and exploded views, respectively. [Figure 1c] An example of a fluid array of a cartridge according to the present invention is schematically shown. [Figure 2a] A longitudinal cross-section of a channel implementing features that enable decelerating or accelerating the flow of biological fluid is shown. [Figure 2b] A longitudinal cross-section of a ventilation channel with a height limitation in the form of a step is shown. [Figure 3] A cross-section of the cartridge in the analysis chamber is shown. [Figure 4] A detection pattern defined by the magnetization generated by a magnetic layer integrated into the support of the cartridge, the magnetic field present in the analysis chamber, and the norm of this magnetic field is schematically shown in plan view. [Figure 5] An analysis apparatus for operating a cartridge according to the present invention is shown. [Figure 6] Elements constituting the cartridge according to the present invention are shown in other figures.

Mode for Carrying Out the Invention

[0018] Figures 1a and 1b show a cartridge 1 for receiving a sample of a biological liquid that is likely to contain an analyte to be detected or whose concentration is desired to be determined. This cartridge 1 comprises a gripping end 1a that enables its manipulation. Here, the gripping end of the cartridge displays a label, which is located on the upper surface side of the cartridge and in particular enables identifying the cartridge using an identification mark, for example a QR code, or carrying any other type of information.

[0019] Cartridge 1 also includes a microfluidic section 1b. This section extends along a main plane intended to be positioned horizontally. As schematically shown in Figure 1c, the microfluidic section 1b includes an injection opening 2 for injecting biological fluids into Cartridge 1, for example, via a pipette. The opening 2 opens into an array of channels 4, 4' that extend within the main plane of Cartridge 1, and allows the flow and distribution of biological fluids into multiple analysis chambers 5 via channels 4, referred to as the “upstream” channels of the array of channels.

[0020] The array of channels in cartridge 1 also includes vent channels 4' that fluidly connect the analysis chamber 5 to the vents 3, respectively, and these vents allow air to be pushed out of this array as the biological fluid progresses into the fluid array of cartridge 1.

[0021] The sample to be analyzed is formed from the biological fluid filling the chamber 5, and therefore, the indicated cartridge 1 allows for multiple analyses of the biological fluid, and the analyses can be performed independently on each sample held within the chamber 5. The opening 2, the vent 3, and the array of channels 4, 4' connecting the opening 2 to the vent 3 define multiple analytical pathways for the cartridge 1.

[0022] In the examples shown in Figures 1a and 1b, a reservoir 2' protruding from the top surface of cartridge 1 is placed over opening 2. The reservoir has sufficient capacity to hold a volume of biological fluid at least equal to the volume of the fluid array of cartridge 1 (i.e., the array of channels 4, analysis chamber 5, and ventilation channel 4' shown in Figure 1c). This volume is typically 5 mm 3 ~500mm 3 More specifically, 20mm 3 ~100mm 3 That's fine.

[0023] Similarly, each vent 3 is covered by a surrounding wall and, according to the principle of a communicative container, holds an excess amount of biological fluid. Advantageously, these walls are at least equal in height to the height of the reservoir 2' to prevent the fluid from leaking out of the cartridge, although such leakage could cause health problems or even damage the analytical instrument into which the cartridge is intended.

[0024] For example, cartridge 1 may have a width and length between 2 cm and 10 cm, and a thickness between 4 mm and 10 mm. Each chamber 5 is typically 1 to 50 mm in size for receiving the sample. 3 , advantageously, 5-25mm 3 It can have a volume of .

[0025] Cartridge 1 consists of a support 6 and an upper cover 7 that covers the support. The support 6 and the upper cover 7 are assembled together by positioning their "main" surfaces facing each other. The fluid array of Cartridge 1 is defined by recesses formed on the main surfaces of the support 6 and / or the main surfaces of the upper cover 7, i.e., on the surfaces of these two elements intended to be assembled together. Each channel of array 4, 4' is defined by two channel walls facing each other, two channel walls defining the height of the channel and two side walls defining the width of the channel. The walls are formed in the recesses from the main surfaces of the support 6 and the main surfaces of the upper cover 7. The same applies to the analysis chamber 5 of Cartridge 1 and any other elements of the fluid array of Cartridge 1.

[0026] The upper cover 7, at least the portion that extends over the analysis chamber 5, is formed of a material that is transparent in the emission wavelength range of the photoluminescent marker when the cartridge is used for immunological analysis as presented in the introduction of this application. It may be a plastic material based on, for example, polycarbonate, cycloolefin copolymer, or polystyrene. It may also be glass. The outer surface of the cover 7 is optically polished at least in front of the analysis chamber 5. These features enable and facilitate the optical analysis of the biological fluid sample contained in the chamber 5, as described in the following sections of this specification.

[0027] Therefore, the fluid array, such as the one shown in Figure 1c as an example, extends within the main plane of the cartridge. It is in millimeters in size, i.e., the channel width of array 4, 4' and the width of the analysis chamber 5 are typically 0.1 to 10 mm. The heights of these elements, i.e., their range in the direction perpendicular to the main plane of cartridge 1, are also in millimeters between 0.1 mm and 10 mm. The biological fluid propagates within this array by capillary action.

[0028] According to a key feature of cartridge 1, one of the walls defining the height of at least one channel is called a "structured wall," which has a step, and the energy of the upstream and downstream surfaces of the step is controlled to selectively accelerate or decelerate the propagation of the fluid in the channel. For simplicity, "surface energy" refers to the surface energy between the surface under consideration and the biological fluid.

[0029] The cartridge 1 according to the present invention utilizes the above-mentioned features to facilitate the filling of the chamber 5 of the fluid array with biological fluid and, more generally, to control the propagation of this fluid within the fluid array of the cartridge.

[0030] More precisely, referring to Figure 2a, at least one channel of cartridge 1 has a step M defining a first segment S1 of the channel, and the structured wall (formed here by the main surface of the support 6) has a first surface energy E1 and a first height e1 defining a first height h1 of the channel. The step M also defines a second segment S2 of the channel, and the structured wall has a second surface energy E2 and a second height e2 defining a second height h2 of the channel. The first height h1 of the channel and the first surface energy E1 of the structured wall are greater than the second height h2 of the channel and the second surface energy E2 of the second segment S2, respectively.

[0031] Variations in channel height, combined with energy variations at the upstream and downstream surfaces of this variation, can influence the fluid flow within the channel.

[0032] Therefore, when the fluid encounters an "upward" step, that is, when the fluid flows from the first section S1 to the second section S2 of the channel by capillary action, the flow is slowed down by the height restriction formed by the step, combined with the lower surface energy of the second segment. Conversely, when the fluid encounters a "downward" step, that is, when the fluid flows from the second section S2 to the first section S1 of the channel by capillary action, its progression is accelerated.

[0033] Surface energy density is a positive magnitude that characterizes an interface, in this case, the interface between the surface of a structured wall and a biological fluid. As is well known, surface energy density can be determined by measuring the contact angle of a water droplet placed on the surface where the energy is measured. A high contact angle greater than 90° indicates a low surface energy density, and the surface is said to be hydrophobic. Conversely, a contact angle less than 90° indicates a high surface energy density, and is a so-called hydrophilic surface. Relatively more hydrophobic surfaces tend to slow down the capillary flow of fluids compared to the fluid flow on relatively more hydrophilic surfaces.

[0034] As an example of these principles, Figure 2b shows an "upward" step in the cartridge's ventilation channel 4', i.e., the channel located between the analysis chamber 5 and the ventilation hole 3. Thus, the fluid moves through this channel toward the ventilation hole 3. The step formed on the support 6 defines the upstream section of the ventilation channel (using the terminology of the general principles of this invention, the first segment of the channel), and this upstream section has a greater surface energy on the support 6 than the surface energy of the downstream section of channel 4' (the side of the ventilation hole 3, the second segment). Advantageously, it is possible to provide such a step in each ventilation channel 4' of cartridge 1 in each of the analysis paths of the cartridge.

[0035] These features of cartridge 1 have the effect of slowing the progression of the biological fluid when it encounters a step after it has progressed by capillary action along the channels of array 4 through the analysis chamber 5. This slowing effect, when occurring in the vent channel 4' which fills more rapidly than others, forces the flow of fluid to the other channels of the array (i.e., supplies fluid to the other analysis chambers 5 of cartridge 1), leading to the equilibrium of fluid progression in each of these paths. Thus, these features of one or more vent channels 4' ensure that the filling of the analysis chamber 5 with biological fluid is carried out in a reliable and reproducible manner and within a filling period of controlled duration. The “upward” step can be located in one or more upstream channels 4 rather than in the vent channel 4'. Some of these steps may be located in the upstream channels 4, while others may be located in the downstream vent channel 4'.

[0036] More generally, the cartridge 1 according to the present invention may have one or more steps in each upward and / or downward analysis path. Thus, it is possible to place a “downward” step in the upstream channel 4 that supplies the chamber 5 of the analysis path, and an “upward” step in the ventilation channel 4' that connects the chamber 5 to the ventilation hole 3 in the same analysis path or another analysis path.

[0037] Advantageously, as shown in Figures 2a and 2b, the step abruptly changes the height of the channel on which the step is located, and the side of the step forms a 90° angle with the wall. However, more generally, this side may form an angle of 60° to 90°. The step may be formed on the support 6 as shown in Figures 2a and 2b, but it is also conceivable that it be formed entirely or partially on the wall opposite the side of the upper cover 7. It may have a height of 0.1 to 0.5 mm in order to effectively slow or accelerate the flow of the liquid. Advantageously, the side of the step has a surface energy closer to the first surface energy E1 than to the second surface energy E2.

[0038] The main surfaces of the support 6 and the upper cover 7 (and therefore the walls of the channels 4, 4' and chamber 5 of the cartridge 1) are preferably selected or treated to be hydrophilic. This feature generally allows for the smooth movement of fluid within the fluid array by capillary action. Surprisingly, the difference between the first surface energy E1 of the first segment S1 of the channel and the second surface energy E2 of the second segment S2 does not need to be very large. In particular, the second surface energy E2 on the "higher" section of the step does not need to be hydrophobic to inhibit the movement of the liquid. When measured as a contact angle, the difference between these two energies E1, E2 may be 5° or more, or 10° or more, and these energies impart hydrophilicity to the surface, i.e., the contact angle remains less than 90°. As an example, the first segment S1 may have a contact angle of 50° to 80° that characterizes the first energy E1, and the second segment S2 may have a contact angle of 65° to 89° (with at least a difference of 5° maintained). Detailed examples of the preparation of the support 6 that enable the control of the first and second surface energies E1, E2 according to what has been presented are given in the remainder of this specification.

[0039] Advantageously, the wall opposite the structured wall has a third surface energy greater than the first and second surface energies E1 and E2. This may be between 15° and 65° (advantageously, still greater than the first and second surface energies), advantageously less than 50°, or close to or less than 35°. This energy leads to the formation of a surface on this opposite wall that is more hydrophilic than the surface of the structured wall, generally allowing the liquid to move into the fluid array by capillary action. The variable energy of the structured wall in different segments S1 and S2 of the channel allows for the regulation of this movement. If the wall having this third energy E3 is provided by the main surface of the upper cover 7, the surface may be treated with a surface agent that tends to increase the hydrophilicity of the surface, such as a poloxamer-based surface agent.

[0040] Of course, it is possible to provide cartridges containing fluid arrays more complex than those used in this example. Therefore, the analytical pathway of the cartridge may include chambers other than the analytical chamber 5, such as one or more incubation chambers located upstream of the analytical chamber 5. These incubation chambers may contain different reagents than those mixed with the fluid before being transported to the analytical chamber 5. Thus, the array of channels 4, 4' may be more complex than that shown in the figure, but such arrays may extend within each analytical pathway from the opening 2 to the vent 3 by fluid-connecting different chambers according to any conceivable configuration.

[0041] An embodiment of the cartridge 1 according to the present invention will be described more precisely with reference to Figures 1b, 6, and 3 (the last figure showing a cross-section of the cartridge 1 in the analysis chamber 5). The cartridge 1 of this embodiment enables the application of magnetic immunoassay and thus implements magnetic particles for marking the presence of analytes in biological liquid samples. This embodiment also enables simple control of the surface energy on different upstream and downstream segments of multiple steps (or a single step) present in the fluid array of this cartridge.

[0042] The support 6 here consists of a rigid substrate 6a including a magnetic layer or zone 6b. The substrate 6a can be formed from a plastic material. The magnetic layer / zone 6b may be placed on or incorporated into the substrate 6a, at least in the analysis chamber 5 of the fluid array.

[0043] The magnetic layer / zone 6b does not necessarily need to cover the entire surface of the substrate 6a.

[0044] The magnetic layer 6b is typically composed of a magnetic composite material, such as ferrite, randomly dispersed in a polymer or oriented along a pre-oriented axis. This magnetic layer may be similar to that of conventional magnetic recording tapes.

[0045] The substrate 6a may also include a non-magnetic film 6c (or more such films) covering the magnetic layer 6b, or more generally, covering the substrate 6a. This non-magnetic film 6c is optional and its purpose is to separate the magnetic layer 6b from the bottom of the analysis chamber 5 when the cartridge 1 is formed by assembling the support 6 to the upper cover 7. To avoid interfering with measurements, the non-magnetic film 6a has low autofluorescence. To clarify, "non-magnetic" refers to a material with a very low magnetic susceptibility, such as a paramagnetic or diamagnetic material. The non-magnetic film 6c may be formed from a plastic material, such as polypropylene.

[0046] In either case, the substrate 6a has an exposed surface A1, which may consist of the substrate 6a itself or, if a non-magnetic layer 6c is present, the non-magnetic layer 6c. This exposed surface A1 is intended to form a first section S1 of the structuring wall of the channel of the fluid array of the cartridge. The exposed surface A1 is designed or treated to have a hydrophilic first surface energy E1. This first surface energy E1 may result from the selection of the material forming the exposed surface, or the selection of its texturing, or the selection of treatment, for example, with plasma or a surfactant, with the aim of making this surface particularly hydrophilic. As already mentioned, this first surface energy E1 may be characterized by a contact angle of 50° to 80°.

[0047] The support 6 comprises a substrate 6a and an interlayer film 6d disposed on the exposed surface A1 of the substrate 6a. The interlayer film 6d in Figure 1b has notches according to a pattern corresponding to the array of upstream channels 4, the analysis chamber 5, and, advantageously, the opening 2. Generally, the interlayer film 6d has notches D intended to define a portion of the fluid array of the cartridge. Therefore, when this interlayer film 6d is assembled to the surface of the substrate 6a to form the support 6, the substrate 6a has recesses that reproduce the notch pattern D of the film 6d. These recesses, in combination with complementary recesses formed in the upper cover 7, constitute the array of channels 4, 4', the analysis chamber 5, and any other elements of the fluid array of the cartridge 1. Note that the notch pattern D of the interlayer film 6d in Figure 1b does not use the indentations of the ventilation channels 4', and therefore these are formed only by recesses formed in the upper cover 7, not the support 6. This configuration, as in the previous example, leads to the formation of an upward step at the inlet of the ventilation channel 4'. More generally, the notch pattern D of the interlayer film 6d corresponds to only a portion of the fluid array of cartridge 1, and constitutes a step in this array.

[0048] The exposed surface A2 of the interlayer film 6d (including the surface opposite to the surface in contact with the substrate 6a) is intended to form a second section S2 of the structured wall of the channel of the fluid array of the cartridge 1. This second section S2 is designed or treated to have a second surface energy E2 (but still hydrophilic) that is smaller than the first surface energy E1. This second surface energy E2 may result from the selection of the material forming the interlayer film or its surface, or from the selection of its texturing or a particular treatment. As already mentioned, this second surface energy E2 can be characterized by a contact angle of 65° to 89° (but greater than the first surface energy E1).

[0049] In this configuration, when the interlayer film 6d having a notch D is assembled to the substrate 6a, the main surface of the support 6 consists of the exposed surface A2 of the interlayer film 6d having a second surface energy E2, and the exposed surface A1 of the substrate 6c having a second surface energy E2 at the height of the notch D of the interlayer film 6d.

[0050] Advantageously, the interlayer film 6d is an adhesive film, which allows the upper cover 7 to be assembled to the support 6 with their surfaces in contact, i.e., surrounding the recess, and thus hermetically sealed. The interlayer film 6d may also be a double-sided adhesive film, and therefore the interlayer film 6d may be able to be reliably assembled to the substrate 6a and the upper cover 7 at the same time. As is well known, such a film consists of a strip, for example, plastic, with both sides coated with an adhesive material. Due to its properties, this adhesive material can naturally have a surface energy lower than the surface energy of the exposed surface of the substrate 6a, and thus constitutes a second surface energy.

[0051] Cartridge 1 is assembled by supplying a substrate 6a on which magnetic strips 6b are provided, regardless of whether it is formed of a double-sided adhesive interlayer film, placing an interlayer film 6d on this substrate 6a to form a support 6, and then assembling this assembly onto the upper cover 7. This assembly is obtained by aligning complementary recesses placed on the main surface of the cover 7 onto recesses defined by the notch pattern D of the intermediate layer 6d of the support 6. In this way, the fluid array of cartridge 1 is defined.

[0052] Of course, it is also possible to provide other films with other notch patterns on the interlayer film 6d to form multiple consecutive upward or downward steps in the channels within the fluid array. In this case, care is taken to maintain a relationship in which the surface energy of the channel segment with the greatest height is greater than the surface energy of the channel segment with the least height at each step.

[0053] Returning to the description of the cartridge's magnetic properties, the magnetic layer 6b contains continuous regions polarized in two different directions (opposite in Figure 3). As shown in Figure 4, which displays the magnetic layer 6b from above, the magnetically polarized regions extend in a single line in the principal direction P in the illustrated example.

[0054] At the interface between two different polarization zones, a region of relatively strong magnetic intensity is generated, which will be referred to as the attractive zone for the remainder of this specification. Thus, the attractive zone is arranged in the form of multiple lines Za oriented in the principal direction P. The specific arrangement of these lines, combined, defines the detection pattern.

[0055] It will be understood that the inline configuration adopted as an example only forms a specific case of the detection pattern. Cartridge 1, more generally, has a magnetic polarization region that defines a well-defined detection pattern, but its configuration can be freely selected.

[0056] Figure 4 also shows the magnetic field Bc generated by the magnetic layer 6b and the norm of this magnetic field. As will be explained below, it may be useful to add an additional external magnetic field Bext to the magnetic field generated by layer 6b. Figure 4 shows this external magnetic field Bext coupled with the magnetic field Bc generated by the above layer and the norm of this coupled magnetic field. It is observed that the application of this external magnetic field Bext may lead to the elimination of certain attractive zones Za that are generated when only the magnetic field provided by the magnetic layer 6b is present. However, in either case, these attractive zones are located along lines Za oriented in the principal direction P, or more generally, according to detection patterns whose characteristics are completely determined.

[0057] In the case of chamber 5 having the dimensions shown above, it is possible to consider forming a detection pattern including 2 to 50 lines, these lines having a thickness of 1 to 150 microns (preferably 5 to 30 microns) and being spaced apart from each other at intervals of 5 to 300 microns, and preferably 25 to 150 microns.

[0058] Returning to the description of Figure 3, Cartridge 1 is prepared to place a controlled amount of magnetic particles 9, typically 25 nm to 500 nm, preferably 100 to 260 nm, with dimensions in nanometer units, in each chamber 5. These particles are typically in the form of beads with superparamagnetic properties and are biocompatible. They may be coated with a polymer (of the polystyrene type) having a surface treatment that allows them to be functionalized with type Ac or Ag proteins. The magnetic particles are bound to a capture element that can associate with the analyte. The controlled amount of particles described above ensures that the concentration of particles in the volume of the chamber, once filled with the biological fluid, is 10 6 ~10 11 The amount is such that it is 1 / mL. A controlled amount of nanoparticles and trapping elements are arranged here in the form of dry clusters 9 on the support 6 of chamber 5.

[0059] Similarly, each of the chambers 5 also contains a dry cluster 10 of detection elements. These detection elements can also be bound to the analyte, and they carry photoluminescent markers, such as fluorescent markers.

[0060] The dry clusters 9 and 10 of the capture and detection elements are also shown in Figure 1b. These can be placed on the support 6 at positions corresponding to the position of the analysis chamber 5 before the upper cover 7 is placed on the support 6. To identify these positions, recesses in the support 6 can be used, in particular to define the cavity of the chamber 5.

[0061] When the biological fluid to be analyzed is introduced into cartridge 1, the fluid flows into the array of channels 4, filling the analysis chamber 5 and propagating through the aeration channel 4'. The presence of at least one step (and changes in surface energy upstream and downstream of this step) in these channels 4, 4' ensures proper filling of all analysis chambers 5 within a specified time, as specified in the preceding paragraph. The detection element 10 and the capture element associated with the magnetic particles 9 are resuspended in the sample in each chamber 5 for mixing with the sample. If the analyte is present in the sample during the subsequent reaction time, a complex is formed containing the capture element, the magnetic particles, the analyte, and the detection element. These complexes are fixed on the support 6 of each chamber 5 by agglomerating in a preferred manner in the magnetic field of maximum strength and are arranged according to a detection pattern defined by the magnetic layer 6b. Excess detection element remains suspended in the sample.

[0062] Each chamber 5 of the cartridge 1 may be prepared to accept capture and detection elements of different properties, thereby allowing multiple analyses to be performed on the biological fluid introduced into the cartridge 1. The detection patterns encoded by the portion of the magnetic layer 6b located in each chamber 5 may also be different for each chamber.

[0063] In either case, if an analyte is present in the sample held in the analysis chamber 5, a detection pattern defined by the magnetic layer 6b is formed.

[0064] To completely control the phenomena occurring within the analysis chamber during the reaction period and to detect the presence and intensity of the detection pattern at the end of this period, it is advantageous to place cartridge 1 inside or on the analyzer as schematically shown in Figure 5.

[0065] The apparatus E includes elements for receiving the cartridge 1 in order to position the cartridge 1 as accurately as possible in the analysis position. In this position, at least one chamber 5 of the cartridge 1 is positioned within the field of view of an image capture device 11, such as an image sensor. This chamber 5 is also positioned within the illumination field of a light source 12, such as a light-emitting diode-based light source. Separators, filters, lenses, etc., can also be provided in the optical path between the light source 12, the chamber 5, and the image capture device 11 of the optical element 13 to improve the quality of the photograph and, in particular, to select an appropriate magnification and depth of field. In this configuration, it is possible to acquire digital images of the sample and support 6 in the chamber 5 in order to reveal the light intensity produced by the fluorescent marker in the image. The cartridge 1 is naturally positioned in the analyzer such that a transparent top cover 7 is located in the optical path, at least in front of the chamber 5, in order to enable this image capture.

[0066] During operation, photoluminescent markers in the solution of the sample or fixed on the support 6 of the illuminated chamber 5 are activated by the light source 12 and visualized in the image plane of the image capture device 11. Thus, a digital image of the distribution of photoluminescent markers on the plane of the support can be obtained.

[0067] Continuing the description of the analyzer E in Figure 3, the apparatus may include a mechanical actuator 14, such as a piezoelectric actuator, that can contact the support 6 of the cartridge to apply a vibratory force to the support 6. The actuator 14 can be activated after the cartridge is inserted into or on the apparatus E to allow for effective resuspension of the capture element, magnetic particles 9, and detection element 10 in the sample.

[0068] Finally, the apparatus E may include a magnetic field source 15, such as an electromagnet, which can be activated to increase the magnetic field generated by the magnetic layer 6b. The magnetic field generated by the magnetic field source 15 may be 1 to 400 mT in the chamber 5, but in any case, it must remain below the coercivity of the magnetic layer 6b so as to preserve its magnetization and the detection pattern defined by this magnetization. The magnetic field generated by the magnetic field source 15 is preferably oriented perpendicular to the surface of the support 6 and added to the magnetic field generated by the magnetic layer 6b, thereby increasing the intensity of the magnetic field in the attraction zone Za and enhancing the detection pattern. As seen earlier, the presence of this magnetic field can lead to modifying the inline arrangement of the attraction zones Za, or more generally, redefining the detection pattern. The magnetic field generated by the magnetic field source 15 may be continuous or pulsed, in which case the pulse duration is typically longer than 1 ms. The magnetic field generated by the magnetic field source 15 also allows for the magnetization of superparamagnetic particles in the sample. In this way, the movement of these particles and composites is facilitated when they are positioned toward the surface of the support 6 in order to immobilize them.

[0069] To operate the analysis device E and perform digital processing of acquired images, the device E also includes a computing device 16. This may be a microcontroller, microprocessor, or FPGA circuit. Strictly speaking, in addition to the computing means, the computing device 16 also includes a memory component that enables the storage of data and computer programs that enable the device E to operate. The computing device 16 may also include an interface component (of the USB interface type) for exchanging data or for enabling the analysis device E to be connected to maintenance equipment. The interface component may also include a screen and control buttons to enable the operator to use the device E. The computing device 16 is connected, for example, by an internal bus to the image capture device 11, light source 12, mechanical actuator 14, and magnetic field source 15, to coordinate their operation and / or collect generated data, for example, digital images provided by the image capture device 11.

[0070] Therefore, once the cartridge 5 is placed in or on the analyzer E by the operator and held in the analysis position by the receiving element, the following series of operations may be performed by the computing device 16, for example, after the device E is activated by a control button: - The mechanical actuator 14 is activated to apply a vibrational force to cartridge 1, initiating or accelerating the resuspending of the capture element, magnetic particles, and detection element in the sample. This moment of activation marks the start of the capture period. - The magnetic source 15 is activated to facilitate the immobilization of magnetic particles, whether composite or uncomposite with the analyte, on the support 6 in the chamber 5. - The light source 12 is turned on, and then, when the capture period ends, the image capture device 11 is activated to acquire images of the sample and support. The images are transferred from the image capture device 11 to the memory component of the computing device 16 so that processing operations can be performed there. - The image is processed to determine a detection signal that represents the presence or concentration of the analyte in the sample. - The detection signal is processed to provide information indicating the presence, absence, and / or concentration of the analyte in the sample, expressed on a standard scale, e.g., as a percentage per mL.

[0071] Naturally, the present invention is not limited to the embodiments described, and modified embodiments may be added thereto without departing from the scope of the invention as defined by the claims.

Claims

1. An optical cartridge (1) for analyzing biological fluids, comprising a liquid injection opening (2) for injecting liquid into channels (4, 4') through which liquid seeps out by capillary action, wherein the array of channels (4, 4') defines a plurality of analysis paths, each comprising an analysis chamber (5), and the array of channels (4, 4') includes, for each analysis path, an upstream channel (4) for fluid connection of the opening (2) to the analysis chamber (5) and a ventilation channel (4') for fluid contact of a vent hole (3) to the analysis chamber (5), and the cartridge (1) comprises a support (6) having a main surface and a part formed of at least partially transparent material, also having a main surface. The upper cover (7) and the support (6) are formed by their main surfaces, with one being assembled to the other, and at least a portion of the array of channels (4, 4') consists of complementary recesses partially formed on the main surface of the support (6) and partially formed on the main surface of the upper cover (7), and each channel is defined by a channel wall called a “structuring wall” provided by the support (6) and an opposing channel wall provided by the upper cover (7), the two walls facing each other defining the channel height, the structural wall having a step (M), with on both sides of the step respectively: - The structured wall has a first surface energy (E1) and a first height (e1) that defines a first height (h1) of the channel, and - The structured wall defines a second segment (S2) of the channel having a second surface energy (E2) and a second height (e2) that defines a second height (h2) of the channel; The first height (h1) of the channel and the first surface energy (E1) of the structured wall are greater than the second height (h2) and second surface energy (E2) of the channel, respectively; The support (6) is: - A rigid substrate (6a) having the first surface energy (E1), wherein a magnetic layer (6b) is incorporated and is disposed beneath a non-magnetic film covered with a magnetic film (6b); - An interlayer film (6d) having the second surface energy (E2) and disposed on the substrate (6a), wherein the interlayer film (6d) has a notch pattern (D) for defining the portion of the fluid array of the cartridge (1), forming the recess of the support (6), and exposing the exposed surface (A1) of the substrate (6a), The main surface of the support (6) is composed of an exposed surface (A2) of the interlayer film (6d) having the second surface energy (E2) and an exposed surface (A1) of the substrate (6a) having the first surface energy (E1), in the optical cartridge (1).

2. The analytical cartridge (1) according to claim 1, wherein the wall facing the structured wall is planar and has a third surface energy greater than the first surface energy (E1) and the second surface energy (E2).

3. The analytical cartridge (1) according to claim 1 or 2, wherein the step has a side surface, and the surface energy of the side surface of the step is closer to the first energy (E1) than to the second energy (E2).

4. The analysis cartridge (1) according to any one of claims 1 to 3, wherein the main surface of the support (6) and the main surface of the upper cover (7) have hydrophilic properties.

5. The analytical cartridge (1) according to any one of claims 1 to 4, wherein a step (M) is located within at least one ventilation channel (4') and tends to reduce the height of the ventilation channel (4') in the direction of the fluid flow.

6. The analytical cartridge (1) according to any one of claims 1 to 5, comprising at least one incubation chamber located fluidly upstream of the analytical chamber (5) in the analytical pathway.

7. The analysis cartridge (1) according to claim 6, wherein the analysis chamber (5) and / or the incubation chamber includes at least one reagent.

8. The analysis cartridge (1) according to claim 7, wherein the at least one reagent includes a photoluminescent marker, and the upper cover (7) is formed of a material that is transparent in the wavelength range of the photoluminescent marker, at least in the portion that extends into the analysis chamber (5).

9. The analysis cartridge (1) according to any one of claims 6 to 8, wherein the upper cover (7) has at least a portion of an optically polished outer surface.

10. The analytical cartridge (1) according to any one of claims 1 to 9, wherein a reservoir (2') is placed in the opening (2), and a surrounding wall having a height at least equal to the height of the reservoir (2') is placed in each of the ventilation holes (3).

11. The analytical cartridge (1) according to any one of claims 1 to 10, wherein the interlayer film (6d) is an adhesive film, and more preferably a double-sided adhesive film.

12. The analysis cartridge (1) according to any one of claims 1 to 11, wherein the magnetic layer (6b) includes a magnetic polarization region that defines a specific detection pattern.

13. A method for manufacturing a cartridge (1) according to any one of claims 1 to 12, comprising: providing the support (6) and the upper cover (7); and assembling the support (6) to the upper cover (7) by arranging their respective main surfaces facing each other, thereby forming opposing walls that define the channels (4, 4').

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