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    • 专利摘要:
    An electronic nose detection system capable of detecting and identifying a set of compounds likely to be present in a gas sample, which detection system comprises a plurality of cross-reactive detection sensors for providing signals representative of the presence of one or more compounds of said set in the gas sample, and is characterized in that it further comprises at least one reference sensor for providing a signal representative of the measurement noise of the detection system . It also relates to an electronic nose comprising such a detection system.
    公开号:FR3071061A1
    申请号:FR1758547
    申请日:2017-09-14
    公开日:2019-03-15
    发明作者:Yanxia Hou-Broutin；Sophie Brenet；Thierry Livache；Cyril HERRIER；Tristan Rousselle
    申请人:Centre National de la Recherche Scientifique CNRS；Commissariat a lEnergie Atomique CEA；Universite Grenoble Alpes；Aryballe Technologies SCA；Commissariat a lEnergie Atomique et aux Energies Alternatives CEA；
    IPC主号:
    专利说明:

    TECHNICAL AREA
    The invention relates to the field of electronic noses.
    More specifically, the invention relates to an improved detection system for an electronic nose as well as an electronic nose comprising such a detection system.
    The invention has many applications and, in particular, in environmental protection, in particular for monitoring olfactory pollution and the quality of more or less confined atmospheres, in monitoring sites manufacturing, storing, handling and / or likely to be contaminated with potentially dangerous or odorous volatile matter, in health, for example to offer a substitute for smell to people suffering from anosmia or to detect volatile biological markers, in the agro-food, for example for the detection of contamination in a production and / or distribution chain of food products, as well as for the control of any product having an odor.
    PRIOR STATE OF THE ART
    The term "electronic nose" is used to detect and identify odors and, therefore, target compounds in the gas phase.
    The electronic nose owes its name to the analogy that exists between its functioning and that of the human olfactory system.
    An electronic nose mainly consists of three systems, namely:
    (1) a gas phase sampling system to be analyzed;
    (2) a detection system which comprises a network of sensors capable of interacting in a physico-chemical manner with the target compounds, the sensors playing the role of olfactory receptors;
    (3) a computer system for processing and analyzing the responses emitted in the form of signals by sensors in the form of signals following a physico-chemical interaction, this system playing the role of the brain.
    Like all analysis devices whose operation is based on the emission of signals by sensors, the electronic noses are the seat, on the one hand, of parasitic signals which we group under the name of "measurement noise" », Which are superimposed on the useful signals, that is to say on the information that one seeks to recover, and, on the other hand, on a drift of the sensors.
    Measurement noise can be caused by a multitude of factors external or internal to the electronic nose such as variations in temperature, pressure, humidity and, in particular, by fluctuations in the measurement system linked to variations in the aforementioned factors during of measure. This noise can occur at any time and lead to errors in the interpretation of the signals emitted by the sensors.
    The drift of the sensors consists in a gradual variation over the long term of the signals emitted by the sensors which is observed while the sensors are placed in the presence of the same target compounds and under the same operating conditions. It is induced by complex physicochemical mechanisms: it could in particular be due to poisoning of the sensors or to their aging but it could also be due to changes in physical, environmental parameters (such as temperature, pressure and humidity) and / or experimental (such as a heating phenomenon of the components of the electronic nose).
    In biosensors or biochips, the operation of which is based on the key-lock principle, that is to say that a biologically active molecule (for example, an antigen) is recognized by a specific ligand (for example, a antibodies specific for this antigen), ligands that are not specific for the molecules to be analyzed are generally used as negative controls in order to determine the measurement noise and any drift from the sensors and, thus, validate the signals emitted by these sensors.
    On the other hand, in electronic noses, whose operation is based on the principle of cross-reactivity, that is to say that each ligand, called receptor, interacts with more or less affinity with the target compounds, all the signals emitted by the sensors are taken into account, whether they are strong or weak, and it is all of these signals which constitutes a recognition pattern (or "recognition pattern" in English), this pattern being characteristic of '' a target compound and which can be considered as a fingerprint of this compound.
    Thus, in the case of electronic noses, it is currently impossible to determine whether the weakness of a signal emitted by a sensor corresponds to a lack of affinity of this sensor for one or more target compounds or to measurement noise.
    To determine a potential drift of the sensors, it has been proposed to use one or more reference gases (cf. Handbook of Machine Olfaction: Electronic Nose Technology, chapter 13, John Wiley & Sons 2006, below reference [1]) . The idea is to carry out measurements with the reference gas or gases at the start of the measurement series, then at certain time intervals as long as the sensors are used. The change in response of the sensors to the reference gas (s) is taken as a measure of the change in response for all other measurements. Consequently, to obtain a good estimate of the drift for gas samples to be analyzed, it is necessary to find a reference gas which perfectly reflects the drift likely to be obtained with these samples. However, it is very difficult, if not impossible, to find such a reference gas.
    In addition, many methods have been developed to reduce the effects of drift. They are often based on mathematical models to compensate for changes in sensor performance. These methods can be divided into four main categories: those involving pre-processing of the signals emitted by the sensors, periodic calibration, data harmonization methods and adaptive methods (cf. S. Di Carlo and M. Falasconi, Drift correction methods for gas chemical sensors in artificial olfaction Systems: technigues and challenges. InTech: 2012, hereafter reference [2]). If some of these methods like adaptive methods (neural networks, evolutionary algorithms, ...) seem promising, they remain difficult to use in practice today.
    It follows from the above that being able to determine the measurement noise and / or a drift of the sensors of an electronic nose and, if there is drift, reducing the effects of this drift remains a major problem knowing that the existence of 'high noise and / or drift from the sensors can hinder the use of this type of device for a lack of reliability and reproducibility.
    The invention aims precisely to provide a solution to this problem.
    STATEMENT OF THE INVENTION
    The invention therefore firstly relates to a system for detecting an electronic nose capable of detecting and identifying a set E of compounds capable of being present in a gas sample, which detection system comprises a plurality of sensors reactivity detection system to provide signals representative of the presence of one or more compounds of set E in the gas sample, and is characterized in that it further comprises at least one reference sensor for provide a signal representative of the measurement noise of the detection system.
    Thus, according to the invention, it is proposed to provide, in a detection system for an electronic nose, the presence of at least one sensor (that is to say one or more sensors) whose function does not is not to provide information on the compounds likely to be present in the gas sample but to give information on the measurement noise of this detection system and, therefore, to allow a correction of possible noise drift from measurement and / or detection sensors.
    In what precedes and what follows, one hears:
    * by “sensor”, an assembly which comprises a sensitive part which comprises at least one receptor capable of interacting in a physicochemical manner with at least one of the compounds of assembly E, and a measurement system, typically called transducer, the function of which is to measure a variation of a physical quantity resulting from the physicochemical interaction and to convert this measurement into an exploitable signal, it being understood that each of the sensors of the detection system can include its own measurement system or share with other sensors a common measurement system;
    * by “cross reactivity”, the fact that the sensitive part of a detection sensor can interact in a physico-chemical way with different compounds of set E and that conversely a compound of set E can interact in a physical way -chemical with the sensitive part of different detection sensors;
    * by “measurement noise”, the part of a signal emitted by a sensor which is induced by factors other than its physicochemical interaction with one of the compounds of set E, for example a variation in temperature, a variation in pressure, a variation in humidity, a variation in the supply voltage of the detection system, vibrations, etc. ;
    * “drift of the measurement system” means a gradual change over time in the average level of the measurement noise; and * by “drift of a sensor”, a progressive variation in time of the signal emitted by a sensor compared to the signal that this sensor is supposed to emit under the same conditions, that is to say when it is exposed the same gas sample and with the same operating parameters; the drift of a sensor corresponds to the sum of the drift of the measurement system and the chemical drift of the sensor, i.e. a progressive variation over time of the ability of the sensitive part of this sensor to interact physicochemically with at least one of the compounds of the set E.
    Furthermore, the term “receptor” is intended to mean any chemical molecule, simple or complex (that is to say which can, in particular, be a macromolecule), which, by itself or when it is associated with one or more other receptors within a mixture of receptors, is capable of interacting in a physicochemical manner with one or more compounds of the set E, this physicochemical interaction typically residing in a sorption and, more specifically, an adsorption.
    According to the invention, the detection system preferably comprises a substrate comprising a surface on which the sensitive parts of the detection sensors and the sensitive part of the reference sensor are arranged, in which case the surface of the substrate advantageously comprises:
    a plurality of sensitive zones, each of these sensitive zones corresponding to the sensitive part of one of the detection sensors and comprising at least one receptor capable of interacting in a physico-chemical manner with at least one compound of the set E , and
    at least one sensitive zone which corresponds to the sensitive part of the reference sensor and which is functionalized with at least one compound which does not interact in a physico-chemical manner or only very weakly with the compounds of set E. This compound is a fluorinated compound which is chosen from compounds comprising at least one perfluorinated terminal alkyl group, that is to say at least one -CF 3 group, and fluorinated polymers, this type of compound and of polymers having the advantage to present both chemical inertness and non-wetting properties.
    Preferably, the fluorinated compound is chosen from the compounds of formula C v F 2v + 2 in which v is an integer ranging from 4 to 20, and the compounds of formula C w F 2w + i- (L) xZ in which w is an integer ranging from 1 to 12, x is worth 0 or 1, L represents a divalent spacer group while Z represents a group suitable for allowing the fixing, by covalent bonds or not, of the compound on the surface of the substrate.
    The divalent spacer group may in particular be a linear or branched, saturated or unsaturated hydrocarbon group comprising from 1 to 20 carbon atoms and optionally one or more heteroatoms, this or these heteroatoms being typically chosen from oxygen, nitrogen, sulfur and silicon. Thus, the divalent spacer group is, for example, a divalent alkylene group comprising from 1 to 20 carbon atoms and, more preferably, from 1 to 12 carbon atoms.
    Advantageously, Z represents a thiol, amine, silanol, carbonyl or carboxyl group.
    According to a particularly preferred arrangement of the invention, the fluorinated compound is a perfluoralcanethiol of formula CF 3 (CF 2 ) y (CI-l 2 ) z SI-1 in which y is an integer ranging from 0 to 11 and z is an integer ranging from 1 to 20 and preferably from 1 to 12.
    Examples of such a fluorinated compound that may be mentioned are 1 / 7.1 / 7 trifluoroethanethiol, 1 / 7.1 / 7.2 / 7.2 / 7-perfluoropentanethiol, 1 / 7.1 / 7.2 / 7.2 / 7-perfluorohexanethiol, 1 / 7.1 / 7.2 / 7.2 / 7-perfluorooctanethiol and 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodecanethiol.
    As previously indicated, the fluorinated compound can also be a fluorinated polymer, in which case it is advantageously chosen from polytetrafluoroethylenes, polyvinyl fluorides, polyvinylidene fluorides, perfluoroalkoxy alkanes, fluorinated ethylene and propylene copolymers and poly (ethylene-co-tetrafluoroethylene).
    According to the invention, the sensitive area corresponding to the sensitive part of the reference sensor can be formed by any of the surface functionalization techniques known to those skilled in the art such as physical or chemical adsorption, grafting covalent, molecular beam epitaxy, thin film deposition, molecular self-assembly, etc., it being understood that the choice of this technique will depend on the chemical nature of the substrate surface, the chemical nature and the molecular size of the compound used to functionalize said sensitive zone as well as the measurement system of the reference sensor.
    Among these techniques, preference is given, within the framework of the invention, to molecular self-assembly.
    According to another particularly preferred arrangement of the invention, the surface of the substrate is a passivated surface, that is to say that it has been subjected to a treatment capable of minimizing the chemical interactions likely to occur between this surface and the compounds of set E and therefore reduce poisoning and aging of the sensitive parts of the detection sensors.
    In which case, the substrate surface is preferably passivated with at least one fluorinated compound which, too, is chosen from compounds comprising at least one perfluorinated terminal alkyl group and fluorinated polymers and, in particular, those previously mentioned.
    According to the invention, this fluorinated compound can be the same compound as that with which the sensitive area corresponding to the sensitive part of the reference sensor is functionalized or else be a different compound, provided that it is chosen from the compounds comprising at least one perfluorinated terminal alkyl group and fluorinated polymers.
    As previously indicated, each of the sensors that the detection system includes can include its own measurement system - or transducer - or share with other sensors a measurement system that is common to them. In both cases, the measurement system can be any measurement system making it possible to generate an exploitable signal during the physicochemical interaction between a compound in the gaseous state and the sensitive part of a sensor and can, in particular, be of the resistive, piezoelectric, mechanical, acoustic or optical type. In other words, the sensors can be resistive, piezoelectric, mechanical, acoustic and / or optical sensors.
    However, in the context of the invention, it is preferred that the sensors are surface plasmon resonance optical sensors. This type of transduction, which is known per se, generally combines a light source, for example of the LED type, in order to cause a plasmon excitation and a CCD camera to record the signal resulting from the plasmon resonance. As such, it is particularly preferred that the signals emitted by sensors are tracked in imaging mode which consists in tracking the signal variations of all the pixels constituting the image of the CCD camera used.
    The substrate is made of a material suitable for the measurement system. Thus, if the measurement is carried out by resonance of the surface plasmons, then the substrate preferably comprises a glass prism, one face of which is covered with a metallic layer, preferably gold or silver, typically 10 nm to 100 nm thick. This metallic layer can be passivated as previously mentioned.
    As will be demonstrated in the following examples, the invention has many advantages.
    In fact, by providing the detection system with a reference sensor whose function is to provide a signal representative of the measurement noise of this detection system, the invention makes it possible, in addition to knowing this measurement noise and, therefore, to subtract it from the signals emitted by the detection sensors with, as a result, greater reliability and greater reproducibility of the operation of the electronic nose, to detect any drift of the measurement system as well as any drift of the detection sensors and, consequently, to correct accordingly, the signals emitted by the detection sensors with, again, the key, greater reliability and greater reproducibility of the operation of the electronic nose.
    In addition, by providing for passivating the surface of the substrate on which the sensitive parts of the detection sensors and of the reference sensor of the detection system are or will be arranged, the invention also makes it possible to reduce the drift of the detection sensors. , poisoning and aging of the sensitive parts of the detection sensors and, thereby, giving greater stability and a long service life to the electronic nose.
    The subject of the invention is also an electronic nose capable of detecting and identifying a set E of compounds capable of being present in a gas sample, which electronic nose is characterized in that it comprises a detection system as previously described.
    According to the invention, the electronic nose is preferably dedicated to the detection and identification of volatile organic compounds, hydrogen sulfide (H 2 S) and ammonia (NH 3 ), these compounds being able to be alone or mixed in the gas sample.
    In the foregoing and what follows, a “volatile organic compound” is defined in accordance with Directive 1999/13 / EC of the European Council of March 11, 1999 under which:
    - a volatile organic compound is "any organic compound having a vapor pressure of 0.01 kPa (or 9.87.10 5 atm) or more at a temperature of 293.15 K (or 20 ° C) or having a corresponding volatility in the specific conditions of use ”(cf. paragraph 17 of article 2 of the Directive);
    - an organic compound is "any compound comprising at least the carbon element and one or more of the following elements: hydrogen, halogens, oxygen, sulfur, phosphorus, silicon or nitrogen, with the exception of carbon oxides and carbonates and bicarbonates inorganic ”(cf. paragraph 16 of article 2 of the Directive).
    Thus, are considered in particular as volatile organic compounds certain acyclic hydrocarbons, saturated or unsaturated, such as ethane, propane, n-butane, n-hexane, ethylene, propylene, 1,3-butadiene and acetylene, certain non-aromatic, saturated or unsaturated cyclic hydrocarbons, such as cyclopropane, cyclopentane and cyclohexane, certain aromatic hydrocarbons such as benzene, toluene, xylenes and ethylbenzene, certain halogenated hydrocarbons such as dichloromethane, trichloromethane, chloroethane, trichlorethylene and tetrachlorethylene, certain alcohols such as methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol and propylene glycol, certain aldehydes such as formaldehyde , acetaldehyde, propanai and 2-propenal (or acrolein), certain ketones such as acetone, methyl ethyl ketone, 2-butanone and methyl vinyl ketone, certain esters such as methyl acetate, ethyl acetate, isopropyl acetate and isoamyl butyrate, certain ethers such as diethyl ether, ethylene glycol n-butyl ether (EGBE) and 1,4-dioxane, certain acids such as acetic acid and propanoic acid, certain amines such as ethylamine, dimethylamine, trimethylamine, diethylamine and amylamine, certain amides such as dimethylformamide, sulfur compounds such as methyl mercaptan (or methanethiol) and ethyl mercaptan (or ethanethiol), and certain nitriles such as acetonitrile and acrylonitrile.
    Other characteristics and advantages of the invention will emerge from the additional description which follows and which is given with reference to the appended figures.
    It goes without saying, however, that this additional description is given only by way of illustration of the object of the invention and should in no case be interpreted as a limitation of this object.
    BRIEF DESCRIPTION OF THE FIGURES
    Figures 1 to 3 schematically illustrate three exemplary embodiments of the substrate of a detection system according to the invention, in which the sensitive parts of the detection sensors and of the reference sensors are arranged on the surface of a common substrate.
    FIG. 4 is a differential image obtained by surface plasmon resonance imaging (or SPRi) after exposure of a detection system according to the invention, with non-passivated substrate, to a gas sample comprising a VOC, in this case the isoamyl butyrate.
    FIG. 5 illustrates, in the form of a bar diagram, the variation of the reflectivity, noted A% R, as obtained by SPRi for self-assembled layers of 1 / 7.1 / 7.2 / - /, 2 / - / - perfluorodecanethiol and dodecanethiol arranged on the surface of a substrate, depending on the concentration, noted [C] and expressed in mmol / L, of the solutions from which these self-assembled layers were obtained; also shown is the variation in reflectivity obtained for an area of the gold layer (stick denoted Au) forming the surface of the substrate.
    FIG. 6 illustrates the curves of the plasmons as obtained by SPRi for the detection sensors and the reference sensors of a detection system according to the invention, with non-passivated substrate, after exposure to a gas sample consisting solely of air; in this figure, the ordinate axis corresponds to the reflectivity, noted% R, while the abscissa axis corresponds to the angle of incidence, noted Θ and expressed in degrees.
    FIG. 7 illustrates, in the form of a bar diagram, the ratio A% R / AP (variation of the reflectivity on variation of pressure) as obtained by SPRi for ten detection sensors, denoted DI to D10, and a reference sensor, denoted RI, of a detection system according to the invention, with a non-passivated substrate, in response to an overpressure (ΔΡ); also shown is the ratio A% R / AP obtained for an area of the gold layer, denoted Au, forming the surface of the substrate.
    FIG. 8A illustrates the variation without correction of the reflectivity, noted A% R, as a function of time, noted t and expressed in minutes, as obtained by SPRi for exposure to a gas sample comprising isoamyl butyrate, on which one observes a coherent noise and a jump of signal due to disturbances of the measurement system, while figure 8B corresponds to figure 8A but after correction of the data by the reference sensor.
    FIG. 9 illustrates the evolution of the reflectivity, noted% R, as a function of time, noted t and expressed in minutes, as obtained by SPRi for two detection sensors (lines DI and D2) and a reference sensor ( line RI) of a detection system according to the invention, with a non-passivated substrate, over a period of 155 minutes during which these sensors were successively exposed to five gas samples comprising, for the first one, isoamyl butyrate and for the other four, amylamine; in this figure, the brace A symbolizes the drift of the measurement system; the line RI has been duplicated below the lines DI and D2 and the braces B and C symbolize the chemical drift of the sensors DI and D2 respectively.
    FIG. 10 is a differential image obtained by SPRi after exposure of a detection system according to the invention, with passivated substrate, to a gas sample comprising isoamyl butyrate.
    FIG. 11A illustrates the evolution of the reflectivity, noted% R, as a function of time, noted t and expressed in minutes, as obtained by SPRi for four detection sensors (lines D1, D2, D3 and D4) and a reference sensor (line RI) of a detection system according to the invention, with non-passivated substrate, over a period of 300 minutes during which these sensors were successively exposed to different gas samples each comprising a VOC; in this figure, the evolution of the reflectivity obtained for an area of the gold layer (line Au) forming the surface of the substrate is also shown.
    FIG. 11B is a figure similar to that of FIG. 11A but for a detection system according to the invention, with passivated substrate; this figure therefore does not include an Au line but includes a line PI corresponding to the change in reflectivity obtained for an area of the surface of the passivated substrate.
    FIG. 12A illustrates the variation of the reflectivity, denoted A% R, as a function of time, denoted t and expressed in minutes, as obtained by SPRi for sensors of a detection system according to the invention, with non-substrate passivated, during an exposure of 6 minutes to a gas sample comprising amylamine then during a rinsing of the substrate for 14 minutes under a stream of clean air; in this figure, the vertical dotted line symbolizes the end of the exposure and the start of rinsing.
    FIG. 12B is a figure similar to FIG. 12A but for a detection system according to the invention, with a passivated substrate.
    FIG. 13A illustrates the normalized reflectivity, denoted R nor m, as obtained by SPRi for twenty-six detection sensors, denoted DI to D26, and for a reference sensor, denoted RI, of a detection system according to l invention, with non-passivated substrate, for three exposures to a gas sample comprising isoamyl butyrate; between each exposure to isoamyl butyrate, amylamine was injected several times; also shown in this figure is the normalized reflectivity obtained for an area of the gold layer, denoted Au, forming the surface of the substrate; the points of line A correspond to the normalized reflectivities obtained before the start of the amylamine injections; the points of line B correspond to the normalized reflectivities obtained in the middle of the amylamine injections while the points of the curve C correspond to the normalized reflectivities obtained after the end of the amylamine injections.
    FIG. 13B is a figure similar to FIG. 13A but for a detection system according to the invention, with a passivated substrate, and in which the normalized reflectivity shown for the zone Au in FIG. 11A has therefore been replaced by that obtained for a area of the surface of the passivated substrate, denoted PI.
    FIG. 14A illustrates the normalized reflectivity, denoted R nor m, as obtained by SPRi for eighteen detection sensors, denoted DI to D18, and for a reference sensor, denoted RI, of a detection system according to l invention, non-passivated substrate, for exposures to a gas sample comprising isoamyl butyrate at 6, 14 and 56 days of use; also shown in this figure is the normalized reflectivity obtained for an area of the gold layer, denoted Au, forming the surface of the substrate.
    FIG. 14B is a figure similar to FIG. 14A but for a detection system according to the invention, with passivated substrate, having been exposed to a gas sample comprising isoamyl butyrate at 9, 15 and 61 days of use;
    in this figure, the normalized reflectivity shown for the zone Au in FIG. 14A has therefore been replaced by that obtained for an area of the surface of the passivated substrate, denoted PI.
    FIG. 15 illustrates the variation in reflectivity, denoted A% R, as a function of time, denoted t and expressed in days, as obtained by SPRi for a reference sensor of a detection system according to the invention, with substrate not passivated, denoted SI, and for a reference sensor of two detection systems according to the invention, with passivated substrate, denoted S2 and S3, over a period of 180 days during which these sensors were successively exposed to three gas samples comprising isoamyl butyrate.
    In Figures 1 to 3, the same elements are designated by the same references.
    DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS
    I - EXAMPLES OF REALIZATION OF THE SUBSTRATE OF A DETECTION SYSTEM ACCORDING TO THE INVENTION
    First of all, reference is made to FIG. 1 which schematically illustrates a first embodiment of the substrate 10 of a detection system according to the invention, in which the sensitive parts of the detection sensors and of the reference sensors are arranged on the surface of the same substrate.
    As visible in this figure, the substrate 10 comprises a surface 11 on which is disposed a plurality of sensitive zones referenced Dl, D2, D3, D4, D5, D6 and D7 respectively, which each correspond to the sensitive part of a sensor of detection and which will therefore be referred to as “sensitive detection zones” in the following. There are 7 sensitive areas in FIG. 1 for the sake of simplification of this figure and therefore correspond to 7 detection sensors.
    However, it goes without saying that it is possible to produce a detection system according to the invention comprising a much higher number of detection sensors, for example 100, 500, 1000, 3000, or even 5000 detection sensors. , and, therefore, a substrate on the surface of which is disposed a corresponding number of sensitive detection zones.
    The surface 11 of the substrate 10 also includes a sensitive area referenced RI, which corresponds to the sensitive part of a reference sensor and which will therefore be called "reference sensitive area" in the following. Here too, for the sake of simplification, FIG. 1 only includes a sensitive reference zone, corresponding to 1 reference sensor.
    However, here too, it is possible to produce a detection system comprising a plurality of reference sensors, for example 5.10, or even 50 reference sensors and, therefore, a substrate on the surface of which is disposed a corresponding number of zones. sensitive reference.
    According to the invention, the sensitive detection zones DI to D7 can be created by functionalizing seven distinct zones of the surface 11 of the substrate 10 with one or more receptors, that is to say of one or more compounds capable of '' interact in a physico-chemical way, typically by a sorption and, more specifically, adsorption mechanism, with at least one of the compounds of the set E of compounds that the electronic nose is capable of detecting and identifying in a gas sample.
    This functionalization can be carried out using any of the surface functionalization techniques known to those skilled in the art (physical or chemical adsorption, covalent grafting, molecular beam epitaxy, deposition of thin layers, molecular self-assembly, etc. ) or by several of them, the choice of this or these techniques being in particular a function of the chemical nature of the surface of the substrate, the chemical nature and the molecular size of the receptors as well as the measurement system of the detection.
    In the case where the compounds of the set E are COVs, H 2 S and NH 3 , then the receptors can in particular be chosen from metals, metal oxides, non-fluorinated organic compounds, non-fluorinated polymers, biomolecules such as DNA molecules, oligonucleotides, sugars, peptides, proteins, phospholipids, and derivatives of these biomolecules, or among the various molecular carbon arrangements of the graphene type, nanotubes, carbon graphite, etc. In this regard, the reader may refer to the articles by K. Arshak et al., Sensor Review 2004, vol. 24, pp. 181-198; T. Wasilewski et al., Biosensors and Bioelectronics 2017, vol. 87, pp. 480-494; and AD Wilson and M. Baietto, Sensors (Basel) 2009, vol. 9, pp. 5099-5148, hereinafter references [3] to [5], for further information on the types of receivers that may be used.
    The sensitive reference area RI can itself be created by functionalizing an area of the surface 11 of the substrate 10, which is distinct from the sensitive detection areas DI to D7, with one or more compounds which do not interact in a physico- chemical with the compounds of the set E or, if they interact with one or more of these compounds, give rise to very weak interactions compared to those which are likely to occur between the receptors of the sensitive zones DI to D7 and said compounds of set E.
    Again, this functionalization can be carried out using any of the surface functionalization techniques known to those skilled in the art depending on the chemical nature of the substrate, the chemical nature and the molecular size of the compound (s). as well as the reference sensor measurement system.
    In accordance with the invention, the compound or compounds which do not or only very weakly interact with the compounds of set E are chosen from fluorinated compounds comprising at least one perfluorinated terminal alkyl group, that is to say at least a group -CF 3 , and fluorinated polymers due, on the one hand, to the chemical inertness which characterizes this type of compounds and polymers and, on the other hand, to their non-wetting properties.
    Fluorinated compounds comprising at least one perfluorinated terminal alkyl group can in particular be perfluorinated compounds, that is to say compounds of formula C v F 2v + 2 in which v is an integer ranging from 4 to 20, or compounds of formula C w F 2w + i- (L) x -Z in which w is an integer ranging from 1 to 12, x is 0 or 1 and L represents a divalent spacer group, for example a saturated linear or branched hydrocarbon group or unsaturated, comprising from 1 to 20 carbon atoms and optionally one or more heteroatoms, typically O, N, S and / or Si, while Z represents a group capable of allowing the binding, by covalent bonds or not, of the compounds on the substrate surface.
    For a functionalization by molecular self-assembly - which is the functionalization technique which is preferred within the framework of the invention - the group Z can, for example, be a thiol (-SH) or amine (-NH 2 ) group if the surface of the substrate is made of gold, platinum, silver, palladium or copper, or else a silanol group (-SiOH) if the surface of the substrate is made of glass, quartz, silicon or silica.
    Among the compounds of formula C w F 2w + i- (L) x -Z, preference is given to perfluoralcanethiols of formula CF 3 (CF 2 ) y (CI-1 2 ) z SI-1 in which y is an integer ranging from 0 to 11 and z is an integer ranging from 1 to 20 and, better still, from 1 to 12, such as 1 / 7,1 / 7-trifluoroethanethiol of formula CF 3 CH 2 SH, 1/7, 1 / 7.2 / 7.2 / 7perfluoropentanethiol of formula CF 3 (CF 2 ) 2 (CH 2 ) 2 SH, 1 / 7.1 / 7.2 / 7.2 / 7-perfluorohexanethiol of formula CF 3 ( CF 2 ) 3 (CH 2 ) 2 SH, 1 / 7.1 / 7.2 / 7.2 / 7-perfluorooctanethiol of formula CF 3 (CF 2 ) 5 (CH 2 ) 2 SH and 1/7, 1 / 7.2 / 7.2 / 7-perfluorodecanethiol of formula CF 3 (CF 2 ) 7 (CH 2 ) 2 SH, all available from the company SIGMA-ALDRICH.
    Fluorinated polymers which may be used are in particular polytetrafluoroethylenes (PTFE) such as those sold by the company DUPONT under the name Teflon®, polyvinyl fluorides (PVF) such as those sold by the company DUPONT under the name Tedlar®, fluorides polyvinylidene (PVDF) such as those sold by the company ARKEMA under the name Kynar®, perfluoroalkoxy alkanes (PFA) like those sold by the company DUPONT under the name Teflon®-PFA, copolymers of ethylene and propylene fluorinated (still known under the name of fluorinated ethylene-propylene or FEP) as those marketed by the company DUPONT under the name Teflon®-FEP, and poly (ethylene-co-tetrafluoroethylene) (ETFE) like those marketed by the company DUPONT under the name Tefzel®.
    Reference is now made to FIG. 2 which schematically illustrates a second embodiment of the substrate 10 of a detection system according to the invention, in which the sensitive parts of the detection and reference sensors are also arranged on a common substrate .
    In this example, the substrate 10 differs from that shown in FIG. 1 only in that its surface 11 has been subjected to a passivation treatment with the same compound or the same compounds as that or those forming the sensitive reference area. RI.
    In the case where the sensitive detection zones D1 to D7 are created by covalent grafting or by molecular self-assembly and where the passivation treatment is itself carried out by means of one of these two techniques, then this passivation treatment can be carried out after the creation of the sensitive detection zones D1 to D7, in which case only the parts of the surface 11 of the substrate 10 that are left free by the sensitive detection zones D1 to D7 are passivated and the reference sensitive area RI is chosen one of these passivated parts.
    As a variant, the passivation treatment can also be carried out before the creation of the sensitive detection zones D1 to D7, in which case these sensitive zones can be created either by covering, at the level of seven distinct zones of the surface 11 of the substrate 10, the or the passivation compounds present on these zones of one or more receptors, either by exceeding seven distinct zones of the surface 11 of the substrate 10, for example by lithography, and by functionalizing the zones thus deactivated with one or more receptors. Again, the sensitive reference area RI can then be chosen on one of the parts of the surface 11 of the substrate 10 left free by the sensitive detection zones D1 to D7.
    FIG. 3 schematically illustrates a variant of the second embodiment of the substrate 10 of a detection system according to the invention, variant in which the surface 11 of the substrate 10 has been subjected to a passivation treatment with one or more compounds which are different from that or those forming the sensitive reference zone RI but which are also chosen from compounds comprising a perfluorinated terminal alkyl group and fluorinated polymers.
    Thus, for example, it is possible to use two different compounds chosen from perfluorinated compounds and compounds of formula C w F 2w + i- (L) x -Z as defined above to form the sensitive area of reference RI and passivate the surface 11 of the substrate.
    As a variant, it is also possible to use a perfluorinated compound or a compound of formula C w F 2w + i- (L) x -Z as defined above to form the sensitive reference area RI and to passivate the surface 11 of the substrate 10 with a fluoropolymer such as PTFE.
    Here too, the passivation processing can be carried out after or before the creation of the sensitive detection zones DI to D7 and of the sensitive reference zone RI according to the same methods as those described above.
    It should be noted that FIGS. 1 to 3 correspond to schematic illustrations of embodiments of the detection system according to the invention, the sensitive zones DI to D7 and RI are shown circular in these figures.
    However, it goes without saying that the sensitive detection zones and the sensitive reference zones may have any other shape, for example polygonal and, in particular parallelepiped, or be of any shape.
    Similarly, the sensitive zones DI to D7 and RI are shown separated from each other in FIGS. 1 to 3, but it is entirely conceivable that the sensitive detection zones and the reference sensitive zones are joined to one another. .
    It - PROPERTIES OF A DETECTION SYSTEM ACCORDING TO THE INVENTION WITH NON-PASSIVE SUBSTRATE ll.l - Demonstration by imagery of the difference in sensitivity existing between the detection sensors and the reference sensors vis-à-vis VOCs:
    The present test was carried out using a substrate consisting of a glass prism, covered on one of its faces with a layer of chromium (approximately 2 nm thick), itself covered with a layer of gold (about 50 nm thick) and comprising:
    - a plurality of sensitive detection zones, these zones being formed by self-assembled layers of different cross-reactive receptors (i.e. a receptor can interact with different VOCs and, conversely, a VOC can react with different receptors), each of the receptors comprising a thiol function for its attachment to the gold layer, and
    a plurality of sensitive reference zones, these zones being formed by self-assembled layers of 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodecanethiol, this self-assembly having been carried out by micro-deposition, by means of '' a robot, of a solution comprising 7 mmol / L of this compound on the gold layer.
    This substrate was exposed for 10 minutes to a gas sample comprising a VOC, in this case isoamyl butyrate (CH 3 (CH 2 ) 2 C (O) O (CH 2 ) 2 CH (CH 3 ) 2 ) at a concentration of around 30 ppm, and the interactions between this VOC and the various sensitive areas of the substrate were followed by resonance imaging of the surface plasmons (or SPRi).
    The differential image shown in FIG. 4 was thus obtained.
    SPRi is a technique for optical reading of surface interactions which can be compared to an optical balance: the more interactions there are between a compound and a surface, the more the optical signal emitted by the reading system. A differential image represents the variation of this optical signal compared to a reference image taken before the exposure of the surface to the compound. Also, the clearer an area of the differential image, the higher the chemical interaction between the compound and the corresponding area of the surface. Conversely, the darker an area of the differential image, the weaker the chemical interaction between the compound and the area of the surface.
    As shown in the figure, the differential image presents zones which are very clear, even white, and which correspond to the sensitive zones of detection of the substrate on which the isoamyl butyrate is adsorbed and zones which are black and which correspond to the sensitive reference areas of the substrate on which the isoamyl butyrate has not or only very little adsorbed, which demonstrates that areas of a substrate which are functionalized by 1 / 7.1 / 7.2 / 7,2 / 7-perfluorodecanethiol have real chemical inertness towards VOCs such as isoamyl butyrate.
    11.2 - Comparison between the sensitivity vis-à-vis the VOCs of sensors whose sensitive parts are formed of a perfluoroalkanethiol and that of sensors whose sensitive parts are formed of a non-fluorinated alkanethiol:
    The present test was carried out using a series of substrates consisting of glass prisms, covered on one of their faces with a layer of gold (about 50 nm thick) and comprising, on the one hand , zones formed by self-assembled layers of 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodecanethiol and, on the other hand, zones formed by self-assembled layers of dodecanethiol (CH 3 (CH 2 ) iiSH), the self-assemblies having been obtained by micro-deposition, by means of a robot, of solutions comprising from 5 mmol / L to 10 mmol / L of one of these compounds on the gold layer.
    These substrates were exposed to gas samples comprising 20 ppm of isoamyl butyrate and the interactions between this VOC and the various self-assembled layers present on the substrates were followed by SPRi.
    The results of this test are illustrated in FIG. 5 which shows, in the form of a bar diagram, the variation of the reflectivity, denoted A% R, as obtained for each of the two types of layers and for each of the concentrations, noted [C] and expressed in mmol / L, of the solutions from which these layers were obtained. For comparison, Figure 5 also shows the variation in reflectivity obtained for an area of the gold layer (stick noted Au).
    As shown in this figure, the variation in reflectivity observed for the self-assembled layers of dodecanethiol - which reflects the sensitivity of these layers towards isoamyl butyrate -, although lower than that observed for the layer gold, is systematically higher than that observed for the layers of 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodecanethiol, regardless of the concentration of the solution used for the deposition of these layers.
    As a result, the adsorption of isoamyl butyrate on the dodecanethiol layers is systematically higher than that it is on the 1 / 7.1 / 7.2 / 7.2 / 7.2 / 7-perfluorodecanethiol layers.
    As this figure also shows, the variation of the reflectivity of the self-assembled layers depends on the concentration of the solution used for the deposition of these layers. In the case of 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodecanethiol, the variation in the lowest reflectivity is observed for a concentration ranging from 6 mmol / L to 7 mmol / L, concentration at which this variation is more than twice as small as that obtained for the self-assembled layers of dodecanethiol.
    11.3 - Checking the functionality of the reference sensors:
    To ensure that the dark areas observed in the image of the figure are due to an absence or almost absence of chemical interaction between the isoamyl butyrate and the sensitive reference areas of the substrate described in example ll. l above, this substrate was exposed to a gas sample consisting solely of air (and, therefore, free of any chemical compound capable of interacting with sensitive detection zones) and the plasmon curves were established by SPRi for the zones sensitive detection and reference.
    These curves are illustrated in Figure 6.
    As this figure shows, the plasmon curves obtained for the reference sensitive areas merge with those obtained for the sensitive detection areas.
    The dark areas observed in the image of FIG. 4 are therefore due to an absence or almost absence of chemical interaction between isoamyl butyrate and the sensitive reference areas of the substrate and not to the fact that the SPRi would be out of his area of sensitivity.
    11.4 - Sensitivity of the reference sensors to variations in physical parameters:
    In order to verify that the sensitive reference areas of the substrate described in example ll.l above, although insensitive or only very little sensitive to the presence of VOCs, are nevertheless sensitive to variations in physical environmental or experimental parameters , a so-called “index jump” test was carried out.
    The principle of this test is to vary the refractive index of a gas sample consisting solely of air (and, therefore, free of any chemical compound capable of interacting chemically with the sensitive detection zones of the substrate) by means a physical parameter and to observe whether the variation in the refractive index results or not in a variation in the optical signals obtained by SPRi for the sensitive detection zones and the sensitive reference zones of the substrate.
    In the present case, the test was carried out by applying an overpressure (ΔΡ = 0.5 bar) to the substrate.
    The results of this test are presented in FIG. 7, in the form of a bar diagram expressing the ratio A% R / AP obtained for a reference sensitive area, denoted RI, ten sensitive detection areas, denoted DI to D10 , and for an area of the gold layer, denoted Au, of the substrate.
    As this figure shows, a variation in the refractive index of the gaseous sample whose only origin is a variation in a physical parameter has resulted in an A% R / AP ratio which is comparable for all sensitive areas. of the substrate.
    The sensitivity to variations in physical parameters can therefore be considered to be the same for all sensitive areas of the substrate.
    The reference sensitive zones are therefore not or only very little sensitive to VOCs while being sensitive to variations in physical parameters, here a variation in pressure. They can therefore be used as negative references or zero references of the physico-chemical interactions likely to occur on the substrate with VOCs.
    11.5 - Evaluation of the measurement noise:
    Insofar as, as shown in the previous example, the sensitive reference zones of the substrate described in example 11.1 above are sensitive to variations in physical parameters, the measurement noise of a detection system comprising a such a substrate can be estimated by measuring the short-term fluctuation of the optical signals obtained for these sensitive areas during exposure to a gas sample comprising a VOC such as isoamyl butyrate.
    FIG. 8A shows that the measurement noise normally measured is approximately ± 0.05% R (cf. from 14 to 18 minutes).
    In this figure, there is also a coherent noise, that is to say a noise which is reflected in the same way on all the optical signals emitted by the sensors (cf. from 0 to 12 minutes), as well as 'a signal jump. These phenomena are due to external parameters, for example vibrations for the coherent noise or an abrupt variation of pressure for the jump of signal. As they are not linked to chemical detection, they can be eliminated using the reference sensors of a detection system according to the invention, by subtracting the average optical signal obtained at a time t for the sensitive reference areas from that obtained at the same time t for each of the sensitive detection zones.
    There is thus obtained, for each sensitive detection zone, an “cleaned” optical signal as visible in FIG. 8B.
    11.6 - Evaluation of the drift of the measurement system and of the drift of each detection sensor:
    A test consisting in exposing the substrate described in example ll.l above successively to five gas samples comprising, for the first 22 ppm of isoamyl butyrate, for the second 3.2 ppm of amylamine, for the third 4, 2 ppm of amylamine, for the fourth 5 ppm of amylamine and for the fifth 14.20 ppm of amylamine, over a total duration of 155 minutes and to be followed by SPRi the evolution of the reflectivity for a sensitive reference area , denoted RI, and for two sensitive detection zones of this substrate, denoted DI and D2, throughout the duration of this exposure.
    Thus, FIG. 9 has been established in which the line denoted RI corresponds to the evolution of the reflectivity, denoted% R, as observed for the area RI, while the lines denoted DI and D2 represent the evolution of% R as observed for zones DI and D2 respectively. In this figure, the line RI, which corresponds to the drift of the measurement system, has been duplicated below each of the lines DI and D2.
    As previously mentioned, the drift of the measurement system is a gradual variation over time of the average level of the measurement noise, or baseline of the signal, which can be caused by complex phenomena, which can in particular be linked to environmental variations (by example, a temperature gradient in the case of SPRi), cross-contamination, pollution of the electronic nose by so-called "poisonous" compounds, etc.
    As the reference sensors are only sensitive to variations in physical parameters, the drift of the measurement system can be evaluated as the drift of the signal emitted by these reference sensors as illustrated by the brace noted A in FIG. 9. This drift also affects the detection sensors, it can be corrected by subtracting the signal emitted by a reference sensor from the signals emitted by the detection sensors.
    As also previously mentioned, the drift of a sensor corresponds to the sum of the drift of the measurement system and the chemical drift of the sensor, caused for example by poisoning or progressive chemical pollution of the sensitive part of the sensor.
    By following only the signal emitted by a given detection sensor, it is impossible to distinguish these two sources of drift. On the other hand, the difference between the signal emitted by a detection sensor and that emitted by a reference sensor makes it possible to quantify the chemical drift, sensor by sensor, as illustrated by the braces noted B and C in FIG. 9.
    Being able to determine the chemical drift alone of each detection sensor makes it possible to test the effectiveness of experimental solutions to reduce it as much as possible. Thus, the electronic nose can be made more reliable and reproducible in the long term.
    III - PROPERTIES OF A DETECTION SYSTEM ACCORDING TO THE INVENTION WITH PASSIVATED SUBSTRATE
    It 1.1 - Demonstration by imaging of the effect of a passivation on the adsorption of VOCs on a substrate:
    The present test was carried out by passivating the surface of a substrate as described in example ll.l above but having a functionalization pattern different from the latter (that is to say a different distribution of the sensitive detection and reference zones), using trifluoroethanethiol which, like 1 / 7,1 / 7,2 / 7,2 / 7 perfluorodecanethiol, is a compound with a perfluorinated alkyl group but whose carbon chain is shorter ( 2 carbon atoms instead of 10).
    This passivation was carried out by diffusion on the surface of the substrate of trifluoroethanethiol in the liquid phase.
    This substrate was exposed to a gaseous sample comprising isoamyl butyrate under the same conditions as those described in Example ll.l above and the interactions between this VOC and the various sensitive areas of the substrate were followed, there too, by SPRi.
    The differential image shown in FIG. 10 was thus obtained, under the same conditions of contrast and luminosity as those used for the image of FIG. 4.
    A comparison of these two images shows that the part of the surface of the substrate left free by the sensitive detection and reference zones appears darker in the image of FIG. 10, which means that the adsorption of isoamyl butyrate on this surface is reduced compared to what it is on the surface of a non-passivated substrate.
    Il 1.2 - Reduction of the chemical drift of the sensors:
    A test was carried out by exposing successively:
    - On the one hand, a non-passivated substrate as described in Example ll.l above, with seven gas samples comprising, for the first two isoamyl butyrate (44.2 ppm and 37.1 ppm) , for the third of ethanol (173 ppm), for the fourth of 1-octanol (4.2 ppm), for the fifth of 1-propanol (192 ppm), for the sixth of 1-butanol (75.6 ppm) and for the seventh of isoamyl butyrate (40.6 ppm), and
    - on the other hand, a passivated substrate as prepared in Example III.1 above, with six gas samples comprising, for the first two of isoamyl butyrate (47.9 ppm and 53.2 ppm), for the third of ethanol (168 ppm), for the fourth of 1-octanol (3.8 ppm), for the fifth of 1-propanol (165 ppm) and for the sixth of 1-butanol (82.1 ppm ), and this, over a period of 300 minutes and following by SPRi and for each substrate, the evolution of the reflectivity,% R, for a reference sensitive area, denoted RI, and for four sensitive detection areas, denoted DI to D4, over this period.
    The evolution of the reflectivity was also followed for an area of the gold layer, denoted Au, of the non-passivated substrate and for an area of the surface of the passivated substrate, denoted PI.
    Thus, FIGS. 11A and 11B have been established, FIG. 11A corresponding to the non-passivated substrate and FIG. 11B corresponding to the passivated substrate.
    A comparison of these figures shows that passivation makes it possible to reduce the chemical drift for all of the sensitive detection zones DI to D4. Over 300 minutes (or 5 hours) of analysis, the chemical drift can thus be halved, going from 0.6% Rh 1 (non-passivated substrate) to 0.3% Rh 1 (passivated substrate). For the analysis of a VOC over ten minutes, the chemical drift obtained becomes of the order of the measurement noise, ie 0.05% R.
    Il 1.3 - Resistance of the detection system to a "poison effect":
    Certain VOCs have a particular affinity for substrates covered with a layer of gold and their non-reversible fixation on this type of substrate can result in poisoning of the detection system, resulting in a drop in reliability and reproducibility of detection provided by this system. Amines and thiols adsorb, for example, irreversibly on gold. These compounds can however be targets of interest for certain applications, in particular for the food industry in the case of amines.
    Two tests were therefore carried out to check whether the passivation of a substrate covered with a layer of gold could reduce the poisoning of this substrate.
    The first test was carried out by exposing, on the one hand, a non-passivated substrate as described in Example 11.1 above, and, on the other hand, a passivated substrate as prepared in Example III.1 above, to a gas sample comprising an amine, in this case amylamine (CH3 (CH 2 ) 4NI-12), for five minutes at the end of which the substrates were rinsed for 14 minutes under a flow of air clean.
    The second test was carried out by exposing these same substrates to a series of three exposures to a gas sample comprising isoamyl butyrate. Between each exposure, amylamine was injected several times at a concentration ranging from 3 ppm to 50 ppm.
    In the two tests, the evolution of the reflectivity,% R, was followed by SPRi for a reference sensitive area, denoted RI, and for twenty-six sensitive detection areas, denoted DI to D26. The evolution of the reflectivity was also followed for an area of the gold layer, denoted Au, of the non-passivated substrate and for an area of the surface of the passivated substrate, denoted PI.
    The results of the first test are illustrated, expressed in variations in reflectivity (A% R), in FIGS. 12A and 12B, while the results of the second test are illustrated, expressed in normalized reflectivities (R nO rm), in FIGS. 13A and 13B.
    Rnorm = / oR ° where A% R D is the change in reflectivity for an LnA% RDn detection sensor D and N D the total number of detection sensors.
    These figures show that, in the case of the non-passivated substrate (Figures 12A and 13A), the signals emitted by the majority of the sensors do not return to the baseline after rinsing the substrate under a stream of clean air. The amylamine is therefore fixed irreversibly under the experimental conditions.
    On the other hand, in the case of the passivated substrate (FIGS. 12B and 13B), the return to the baseline is much better and therefore the irreversible fixation of the amylamine has been limited.
    FIGS. 13A and 13B further demonstrate an improvement in the repeatability of the detection system with the passivation. Indeed, the profile obtained for isoamyl butyrate is retained even after exposure to a poisonous compound such as amylamine.
    Il 1.4 - Improvement of the aging of the detection system:
    Two tests were therefore carried out to check whether the passivation of a substrate covered with a gold layer could reduce the aging of the detection system.
    The first test carried out by exposing, on the one hand, a non-passivated substrate as described in Example II.1 above, and, on the other hand, a passivated substrate as prepared in Example III. 1 above, to gas samples comprising from 35 ppm to 55 ppm of isoamyl butyrate, on the 6 th day (with 3 exposures), on the 14 th day (with 2 exposures) and on the 56 th day (with 2 exposures ) of use for the first substrate and the 9th day (with 3 exposures), the 15 th day (with two exposures) and the 61 th day (with two exposures) of use to the second substrate, and following by SPRi and for each substrate the evolution of the reflectivity for a sensitive reference area, denoted RI, and for eighteen sensitive detection areas, denoted DI to D18. The evolution of the reflectivity was also followed for an area of the gold layer, denoted Au, of the non-passivated substrate and for an area of the surface of the passivated substrate, denoted PI.
    The second test was carried out by exposing:
    a non-passivated substrate as described in Example II.1 above, hereinafter called SI,
    a passivated substrate as prepared in Example III.1 above, that is to say passivated by liquid diffusion of trifluoroethanethiol, hereinafter referred to as S2, and
    a substrate prepared by passivating the surface of a substrate as described in Example II.1 above, by liquid diffusion of 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodecanethiol, referred to below -after S3, to gas samples comprising from 35 ppm to 55 ppm of isoamyl butyrate, at 1 week, 2 months and 6 months of use of these substrates, and following by SPRi and for each of the substrates SI , S2 and S3, the evolution of the reflectivity for a sensitive reference area.
    The results of the first test are illustrated, expressed in normalized reflectivities (R nO rm), in FIGS. 14A and 14B while the results of the second test are illustrated, expressed in variations of reflectivity (A% R), in FIG. 15.
    FIGS. 14A and 14B show that, in the case of a non-passivated substrate (SI), the profile obtained on all of the sensors deteriorates over time because the response of each sensor tends towards the same value. Thus, we lose the ability of the electronic nose to differentiate from VOCs. On the other hand, in the case of a passivated substrate (S2 and S3), the profile obtained on all the sensors is well preserved.
    FIG. 15 shows, for its part, that the insensitivity or very low sensitivity to VOCs of the reference sensors is also better preserved with passivation of the substrate. By using trifluoroethanethiol as the passivating compound (S2), the reference sensors are even stabilized for up to six months of use.
    REFERENCES CITED [1] Handbook of Machine Olfaction: Electronic Nose Technology, chapter 13, John Wiley & Sons 2006 [2] S. Di Carlo and M. Falasconi, Drift correction methods for gas chemical sensors in artificial olfaction Systems: technigues and challenges. InTech: 2012 [3] K. Arshak, E. Moore, G. M. Lyons, J. Harris, and S. Clifford, A review of gas sensors employed in electronic nose applications, Sensor Review 2004, vol. 24, pp. 181-198 [4] T. Wasilewski, J. Gqbicki, and W. Kamysz, Bioelectronic nose: Current status and perspectives, Biosensors and Bioelectronics 2017, vol. 87, pp. 480-494 [5] A. D. Wilson and M. Baietto, Applications and Advances in Electronic-Nose Technologies, Sensors (Basel) 2009, vol. 9, pp. 5099-5148
    权利要求:
    Claims (16)
    [1" id="c-fr-0001]
    1. An electronic nose detection system capable of detecting and identifying a set E of compounds likely to be present in a gas sample, which detection system comprises a plurality of cross-reactivity detection sensors for supplying signals representative of the presence of one or more compounds from set E in the gas sample, and is characterized in that it further comprises at least one reference sensor for supplying a signal representative of the measurement noise of the detection system.
    [2" id="c-fr-0002]
    2. Detection system according to claim 1, characterized in that it comprises a substrate comprising a surface on which are arranged the sensitive parts of the detection sensors and the sensitive part of the reference sensor.
    [3" id="c-fr-0003]
    3. Detection system according to claim 2, characterized in that the surface of the substrate comprises:
    a plurality of sensitive zones, each of these sensitive zones corresponding to the sensitive part of one of the detection sensors and comprising at least one receptor capable of interacting physico-chemically with at least one compound of the set E, and
    - At least one sensitive zone which corresponds to the sensitive part of the reference sensor and which is functionalized with at least one fluorinated compound chosen from the compounds comprising at least one perfluorinated terminal alkyl group and the fluorinated polymers.
    [4" id="c-fr-0004]
    4. Detection system according to claim 2 or claim 3, characterized in that the surface of the substrate is a passivated surface.
    [5" id="c-fr-0005]
    5. Detection system according to claim 4, characterized in that the surface of the substrate is passivated with a fluorinated compound chosen from compounds comprising at least one terminal alkyl group perfluorinated and fluorinated polymers.
    [6" id="c-fr-0006]
    6. Detection system according to claim 3 or claim 5, characterized in that the fluorinated compound is chosen from the compounds of formula C v F 2v + 2 in which v is an integer ranging from 4 to 20, and the compounds of formula C w F 2w + i- (L) x -Z in which w is an integer ranging from 1 to 12, x is 0 or 1, L represents a divalent spacer group, while Z represents a group capable of allowing the fixation of the compound on the surface of the substrate, preferably a thiol, amine, silanol, carbonyl or carboxyl group.
    [7" id="c-fr-0007]
    7. Detection system according to claim 6, characterized in that the divalent spacer group is a linear or branched, saturated or unsaturated hydrocarbon group, comprising from 1 to 20 carbon atoms and optionally one or more heteroatoms.
    [8" id="c-fr-0008]
    8. Detection system according to claim 7, characterized in that the divalent spacer group is a divalent alkylene group comprising from 1 to 20 carbon atoms, preferably from 1 to 12 carbon atoms.
    [9" id="c-fr-0009]
    9. Detection system according to any one of claims 6 to 8, characterized in that the fluorinated compound is a perfluoralcanethiol of formula CF 3 (CF 2 ) y (CH 2 ) z SH in which y is an integer ranging from 0 to 11 and z is an integer ranging from 0 to 20, preferably from 1 to 12.
    [10" id="c-fr-0010]
    10. Detection system according to claim 9, characterized in that the fluorinated compound is 1 / 7.1 / 7-trifluoroethanethiol, 1 / 7.1 / 7.2 / 7.2 / 7-perfluoropentanethiol, 1 / 7.1 / 7.2 / 7.2 / 7-perfluorohexanethiol, 1 / 7.1 / 7.2 / 7.2 / 7-perfluorooctanethiol or 1 / 7.1 / 7.2 / 7.2 / 7-perfluorodécanethiol.
    [11" id="c-fr-0011]
    11. Detection system according to claim 3 or claim 5, characterized in that the fluorinated compound is chosen from polytetrafluoroethylenes, polyvinyl fluorides, polyvinylidene fluorides, perfluoroalkoxy alkanes, fluorinated ethylene and propylene copolymers and poly (ethylene-cotetrafluoroethylene).
    [12" id="c-fr-0012]
    12. Detection system according to claim 3, characterized in that the sensitive zone corresponding to the sensitive part of the reference sensor is formed of a self-assembled layer of the fluorinated compound.
    [13" id="c-fr-0013]
    13. Detection system according to any one of claims 1 to 12, characterized in that the detection sensors and the reference sensor are resistive, piezoelectric, mechanical, acoustic and / or optical sensors.
    [14" id="c-fr-0014]
    14. Detection system according to claim 13, characterized in that the detection sensors and the reference sensor are optical sensors with surface plasmon resonance.
    [15" id="c-fr-0015]
    15. Electronic nose capable of detecting and identifying a set E of compounds capable of being present in a gas sample, characterized in that it comprises a detection system as defined in any one of claims 1 to 14.
    [16" id="c-fr-0016]
    16. Electronic nose according to claim 15, characterized in that the compounds of set E are volatile organic compounds, hydrogen sulfide and ammonia.
    S.62676
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    同族专利:
    公开号 | 公开日
    WO2019053366A1|2019-03-21|
    FR3071061B1|2019-09-13|
    EP3665478B1|2021-06-16|
    US20200256793A1|2020-08-13|
    JP2020533605A|2020-11-19|
    ES2883422T3|2021-12-07|
    EP3665478A1|2020-06-17|
    CN111201436A|2020-05-26|
    KR20200056397A|2020-05-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP3185011A1|2015-12-23|2017-06-28|Commissariat A L'energie Atomique Et Aux Energies Alternatives|Gas sensor with increased compactness and selectivity|WO2020193647A1|2019-03-28|2020-10-01|Aryballe Technologies|Method for determining a potential poisoning of a sensor of an electronic nose by a volatile compound|
    WO2021053284A1|2019-09-19|2021-03-25|Aryballe Technologies|Odour identification device, odour identification method and corresponding computer program|
    FR3106212A1|2020-01-10|2021-07-16|Aryballe Technologies|Electronic device, method and computer program for the olfactory assessment of the state of a product|
    JP2022011869A|2020-06-30|2022-01-17|株式会社香味醗酵|Measuring equipment and programs|
    法律状态:
    2018-09-28| PLFP| Fee payment|Year of fee payment: 2 |
    2019-03-15| PLSC| Publication of the preliminary search report|Effective date: 20190315 |
    2019-09-30| PLFP| Fee payment|Year of fee payment: 3 |
    2020-09-30| PLFP| Fee payment|Year of fee payment: 4 |
    2021-09-30| PLFP| Fee payment|Year of fee payment: 5 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1758547A|FR3071061B1|2017-09-14|2017-09-14|IMPROVED DETECTION SYSTEM FOR ELECTRONIC NOSE AND ELECTRONIC NOSE COMPRISING SUCH A SYSTEM|
    FR1758547|2017-09-14|FR1758547A| FR3071061B1|2017-09-14|2017-09-14|IMPROVED DETECTION SYSTEM FOR ELECTRONIC NOSE AND ELECTRONIC NOSE COMPRISING SUCH A SYSTEM|
    ES18780183T| ES2883422T3|2017-09-14|2018-09-11|Improved detection system for electronic nose and electronic nose comprising said system|
    PCT/FR2018/052219| WO2019053366A1|2017-09-14|2018-09-11|Improved detection system for an electronic nose and an electronic nose comprising such a system|
    CN201880059327.2A| CN111201436A|2017-09-14|2018-09-11|Improved detection system for an electronic nose and electronic nose comprising such a system|
    JP2020515688A| JP2020533605A|2017-09-14|2018-09-11|An improved detection system for electronic olfaction and electronic olfaction with such a system|
    US16/647,414| US20200256793A1|2017-09-14|2018-09-11|Detection system for an electronic nose and an electronic nose comprising such a system|
    EP18780183.2A| EP3665478B1|2017-09-14|2018-09-11|Improved detection system for an electronic nose and an electronic nose comprising such a system|
    KR1020207009972A| KR20200056397A|2017-09-14|2018-09-11|Improved detection system for electronic nose and electronic nose comprising such system|
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