Method for preparing a molecular infrared sensor, the molecular infrared sensor obtained and method for detecting an analyte using such molecular infrared sensor

Abstract

A method for making a molecular infrared sensor having a molecularly imprinted polymer sensing device for detecting a desired analyte comprises the following steps: - providing an infrared sensor comprising a sensing device coupled to an integrated circuit for sending a sensing signal from the sensing device to the integrated circuit, wherein the sensing device comprises a sensing element designed to receive an input signal and emit a sensing signal in response to the disturbance generated by the input signal, said sensing element being of a type capable of detecting infrared radiation emitted by an object within the sensor's field of view, and a filtering device operably connected to the sensing element and designed to filter the radiation impinging on the sensing element so that an input signal filtered by said filtering device reaches said sensing element, said filtering device being configured to filter radiation having a wavelength between about 5 and about 20 μm; - treating said filter device to pre-functionalize the filter device to bind at least one functional group to said filter device and obtain a pre-functionalized filter device; - applying to said pre-functionalized filter device a molecularly imprinted polymer (MIP), said molecularly imprinted polymer having at least one receptive site for a desired analyte, to obtain an infrared sensor equipped with a molecularly imprinted polymer detection device suitable for detecting said analyte; - treating said infrared sensor to bind said pre-functionalized filter device to said molecularly imprinted polymer (MIP).

Description

METHOD FOR PREPARING A MOLECULAR INFRARED SENSOR, THE MOLECULAR INFRARED SENSOR OBTAINED AND METHOD FOR DETECTING AN ANALYTE USING SUCH MOLECULAR INFRAREDSENSOR

[0001] The present invention relates to a molecular infrared sensor of the type comprising a molecularly imprinted polymer.

[0002] The invention further relates to a method for obtaining a molecular infrared sensor comprising a molecularly imprinted polymer.

[0003] The invention further relates to a method for detecting an analyte by means of such a molecular infrared sensor comprising a molecularly imprinted polymer.

[0004] The invention further relates to a molecular infrared sensor that is specific for a given analyte.

[0005] The sensor of the invention is particularly suitable for detecting particular analytes, for example analytes containing a protein group, in particular virus molecules. However, by appropriately selecting and varying the type of molecularly imprinted polymer of the sensor, it is possible to obtain molecular sensors suitable for detecting any desired chemical species of analytical interest.

[0006] In general, the problem of providing sensors that, on the one hand, are capable of carrying out precise and reliable detections of a particular analyte and, on the other hand, allow detections to be carried out at contained cost is known. The types of detections performed and the sensors used depend on the particular analyte to be detected.

[0007] For the purposes of the present description, the term analyte is generally understood to mean a chemical species that is to be detected during a chemical or chemico-physical analysis, irrespective of the nature of the chemical species or of the type of detection used to detect the presence of such analyte. In the present description an analyte can be any chemical species to be detected; however, specific reference will be made to the detection of molecules containing a protein group, in particular virus molecules.

[0008] Molecularly imprinted polymers (MIPs) are polymeric materials obtained by so-called molecular imprinting polymerization. Molecular imprinting polymerization is known in the art and makes it possible to prepare polymers having a polymer chain provided with one or more receptive sites, also of different type from one another, suitable for reversibly binding a given target molecule. The molecular imprinting technique provides for carrying out the synthesis of the polymer in the presence of the target molecule of interest, also referred toas the template molecule, which acts as a templating agent for the polymer. MIPs are obtained by polymerizing, generally via radical polymerization, at least one functional monomer with a cross-linking agent in the presence of a templating molecule and subsequently removing the templating molecule from the formed polymer matrix. Upon removal of the templating molecule from the polymer matrix, the latter is provided with cavities conformed in a manner dependent on the templating agent used. Such cavities act as receptive sites for the templating molecule itself, i.e. they are suitable for receiving and reversibly binding the templating molecule. By making a polymer using the molecular imprinting technique, polymers are obtained having cavities defined in the polymer matrix and having a specific affinity for a desired molecule; the cavities act as receptive sites for the molecule chosen as the template in the synthesis process.

[0009] Each molecularly imprinted polymer, by virtue of its high selectivity for the target molecule(s) for which it has been designed, may be highly specific for a desired analyte, or for a precise class of analytes. For this reason MIPs are used in the state of the art as recognition elements in chemical sensors for determining certain analytes. In such chemical sensors, the binding of the target molecule with the specific MIP generates a signal that can be measured by transduction systems, for example of the optical or electrical type. By varying the templating molecule used in the polymerization step and the respective functional monomers, the molecule(s) that the obtained MIP will be able to bind at its receptive sites vary; thus MIPs suitable for binding a given molecule, or certain molecules, can be obtained.

[0010] The term detection device is intended to mean the part of a sensor that performs the desired detection. The detection device comprises a sensitive element that is configured so as to vary one of its properties, for example the dielectric constant or the refractive index, as a function of a change of a given parameter or of the presence / concentration of a particular analyte. The detection device of a sensor is configured to interact with the analyte to be detected, in particular to bind or coordinate the analyte to be detected. Such interaction causes a change in at least one physical or chemico-physical property of the sensitive element that enables detection of the desired analyte.

[0011] The detection devices may comprise a transducer operatively connected to the sensitive element and adapted to receive the signal corresponding to the change in the property of the sensitive element and to transform said signal into an electrical signal measurable by suitable measuring devices.

[0012] Optical filters are known, i.e. transparent means capable of transmitting radiationof certain wavelengths, for example in the visible, ultraviolet or infrared range, absorbing radiation of different wavelengths. In particular, infrared filters are known which allow transmission in the infrared wavelength while shielding wavelengths other than the infrared. The operation of an optical filter is based on one or more of the following phenomena: selective absorption, selective reflection, scattering, interference, polarization. Optical filters are usually arranged upstream of a radiation-sensitive element along the path of the electromagnetic radiation in order to absorb certain wavelengths of the incident radiation and let the remaining wavelengths pass so that they reach the sensitive element and generate the desired perturbation; in this way only the radiation filtered by the optical filters reaches the sensitive element.

[0013] So-called infrared sensors are known in the art, namely sensors having a sensitive element capable of detecting infrared radiation emitted by an object within the field of view (FOV) of the sensor itself. Such sensors are based on detecting the energy emitted, in the form of luminous radiation, by an object at a temperature above absolute zero. Although invisible to the human eye because at a frequency lower than that of light in the visible spectrum, such radiation can be detected by specific electronic devices designed for this purpose. Infrared sensors are suitable for detecting radiation within the infrared range; the IR radiation impinging on the sensitive element produces a change in the temperature of the sensitive element which consequently generates an output signal proportional to the incident IR power. Such sensors are usually passive and are also referred to as PIR (Passive Infrared Sensors) because they do not emit energy but detect the energy emitted by objects; the sensor can thus measure the temperature of the object that emits radiation on the basis of the information contained in the incident radiation, exploiting the Stefan- Boltzmann law.

[0014] Infrared sensors may have various structures; however, in general terms, such sensors comprise a detection device comprising an element sensitive to infrared radiation, or a plurality of elements sensitive to infrared radiation, and a filtering device adapted to filter the electromagnetic radiation and positioned so as to filter the radiation that reaches the infrared-sensitive element. The filtering device is arranged upstream of the infraredsensitive element along the path of the electromagnetic radiation so that the radiation that reaches the sensitive element first passes through the filtering device; the detection device is configured so that only the radiation that has passed through the filtering device reaches the sensitive element.

[0015] The sensitive element sensitive to infrared radiation is usually made of pyroelectricmaterials, i.e. materials that generate energy when exposed to heat. The filtering device is usually configured as a band-pass optical filter which is configured to allow to the sensitive element radiation having a wavelength between about 5 and about 20 micrometres, corresponding to infrared radiation, thereby preventing the infrared-sensitive element from being perturbed by visible light and radiation having a wavelength outside said range. The IR radiation that strikes the sensitive element produces a change in the temperature of the sensitive element itself which consequently generates an output signal that is proportional to the power of the incident IR radiation and can be measured by appropriate measuring systems.

[0016] Microelectronic infrared sensors, also referred to as TMOS sensors, are also known. Such sensors comprise a housing enclosing a support structure on which a detection device is integrated, an interface of an integrated circuit (IC) adapted to receive a detection signal from the detection device and provide a digital signal to a measuring system. The detection device comprises an element sensitive to heat adapted to detect a temperature variation, a band-pass filter arranged upstream of the sensitive element along the light path and adapted to shield the light so as to allow only radiation having a wavelength between 5 and 20 pm, i.e. the infrared wavelength, to reach the sensitive element. The sensitive element is inserted in the integrated circuit (ASIC) and, when struck by an input signal, in particular by infrared radiation, generates a detection signal that is converted via MEMS into an electrical signal. The sensitive element is a TMOS, namely a type of thermal sensor consisting of a thermally insulated and micromachined transistor, manufactured with CMOS-SOI (silicon-on-insulator) MEMS technology; in some versions the sensitive element comprises a matrix of vacuum-floating MOS thermal transistors (TMOS) interconnected and acting as a single sensitive element.

[0017] The integrated circuit comprises a measuring system operatively connected to the sensitive element and adapted to measure the signal generated by the sensitive element. The measuring system may comprise a microprocessor, an amplifier which converts the detection signal from the sensitive element into an analogue voltage signal, and an analogue-to-digital converter used to generate digital information.

[0018] Optical sensors containing a molecularly imprinted polymer fixed on an optical fibre are also known. Such sensors can be prepared, for example, as described in Cennamo et al., Sensors and Actuators B, 188 (2013), 221-226, starting from a plastic optical fibre (POF) having a core made of polymethyl methacrylate (PMMA) and a cladding made of a fluorinated polymer. Each optical sensor comprises a resin platform in which a recess isdefined to house the optical fibre and keep it stably fixed to the platform. A portion of the outer covering of the optical fibre is removed to leave exposed a portion of the core of the optical fibre on which a layer of photoresist material (microposit S1813) and a layer of gold are successively deposited; a layer of molecularly imprinted polymer is deposited or grown on the gold layer.

[0019] EP 3502152 describes an optical sensor of the type indicated above that comprises a molecularly imprinted polymer suitable for the detection of PFAS.

[0020] WO 2021 / 260566 describes an optical sensor of the type indicated above that comprises a molecularly imprinted polymer suitable for detecting COVID-19 molecules.

[0021] However, such sensors are not suitable for use in every detection environment. In particular, such sensors cannot be interrogated directly in air, but must be immersed in an aqueous solvent in order to carry out detection. This limits their use to particular detection environments. Moreover, certain precautions must be taken to ensure the correct use of such sensors. Such sensors therefore have a response time that is not always compatible with the need to make real-time measurements in air.

[0022] Sensors with a molecular sensitive element but of non-synthetic origin, for example enzymes or antibodies, DNA fragments, aptamers, etc., are also known. However, such sensors have a considerable cost and require that a number of precautions be taken to ensure their correct operation. In particular, it is necessary to adjust the pH, detection temperature, etc. Moreover, such sensors have a limited lifetime because they easily degrade over time.

[0023] Such precautions, however, in addition to making the final product very expensive, are not always feasible. Indeed, the use of biological receptors is very often not compatible with applications in environments other than the laboratory, in addition to the fact that their storage requires special care.

[0024] Therefore remains the need to provide sensors suitable for detecting a desired analyte that have a limited cost and at the same time allow reliable detections to be obtained in various detection environments and within reduced times.

[0025] An object of the invention is therefore to provide a sensorthat is reliable in detecting a given analyte, robust and having a limited cost.

[0026] Another object is to provide a sensor that is selective and specific for a particular analyte, or group of analytes, so as to provide reliable and precise detections.

[0027] A further object of the invention is to provide a sensor that is simple to manufacture.

[0028] Another object of the invention is to provide a method of detecting an analyte thatis simple, reliable and reproducible.

[0029] A further object of the invention is to provide a sensor for detecting analytes of interest that can be used in various measuring environments.

[0030] Another object of the invention is to provide a sensor for detecting molecules containing at least one protein group that is simple to use, inexpensive and reliable.

[0031] Another object of the invention is to provide a sensor for detecting virus molecules that is simple to use, inexpensive and reliable.

[0032] A still further object is to provide a sensor that can be used in air or in a desired detection environment.

[0033] In a first aspect of the invention, a method for making an infrared sensor having a molecularly imprinted polymeric detection device for detecting a desired analyte is provided.

[0034] Preferably, said method comprises providing an infrared sensor comprising a detection device coupled to an integrated circuit to send a detection signal from the detection device to the integrated circuit, wherein the detection device comprises a sensitive element adapted to receive an input signal and to emit a detection signal in response to the perturbation generated by the input signal, said sensitive element being of the type suitable for detecting infrared radiation emitted by an object located in the field of view of the sensor, and a filtering device operatively connected to the sensitive element and adapted to filter the radiation impinging on the sensitive element so that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength of between about 5 and about 20 pm.

[0035] Preferably, said method comprises treating said filtering device to bond at least one functional group to said filtering device and obtain a pre-functionalized filtering device.

[0036] Preferably, said method comprises applying onto said pre-functionalized filtering device a molecularly imprinted polymer (MIP), said MIP having at least one receptive site for a desired analyte, so as to obtain an infrared sensor provided with a molecularly imprinted polymeric detection device suitable for detecting said analyte.

[0037] Preferably, said method comprises treating said infrared sensor to bond said prefunctionalized filtering device to said molecularly imprinted polymer (MIP).

[0038] In a second aspect of the invention, there is provided a method for making a molecular infrared sensor having a molecularly imprinted polymeric detection device for detecting a desired analyte.

[0039] Preferably, said method comprises providing an infrared sensor comprising a detection device intended to be connected to a measuring system to send a detection signalfrom the detection device to the measuring system, wherein the detection device comprises a sensitive element adapted to receive an input signal and to emit a detection signal in response to the perturbation generated by the input signal, said sensitive element being of the type suitable for detecting infrared radiation emitted by an object located in the field of view of the sensor, and a filtering device operatively connected to the sensitive element and adapted to filter the radiation impinging on the sensitive element so that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength of between about 5 and about 20 pm.

[0040] Preferably, said method comprises treating said filtering device to pre-functionalize said filtering device by bonding at least one functional group to said filtering device and obtaining a pre-functionalized filtering device.

[0041] Preferably, said method comprises applying onto said pre-functionalized filtering device a molecularly imprinted polymer (MIP), said MIP having at least one receptive site for a desired analyte, so as to obtain an infrared sensor provided with a molecularly imprinted polymeric detection device suitable for detecting said analyte.

[0042] Preferably, said method comprises treating said infrared sensor to bond said prefunctionalized filtering device to said molecularly imprinted polymer (MIP).

[0043] In a third aspect of the invention, there is provided a method for making an infrared sensor having a molecularly imprinted polymeric detection device for detecting a desired analyte.

[0044] Preferably, said method comprises providing an infrared sensor comprising a detection device coupled to an integrated circuit to send a detection signal from the detection device to the integrated circuit, wherein the detection device comprises a sensitive element adapted to receive an input signal and to emit a detection signal in response to the perturbation generated by the input signal, said sensitive element being of the type suitable for detecting infrared radiation emitted by an object located in the field of view of the sensor, and a filtering device operatively connected to the sensitive element and adapted to filter the radiation impinging on the sensitive element so that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength of between about 5 and about 20 pm.

[0045] Preferably, said method comprises treating said filtering device to pre-functionalize said filtering device so as to bond at least one functional group to said filtering device and obtain a pre-functionalized filtering device.

[0046] Preferably, said method comprises preparing a polymerizable mixture comprising:at least one polymerizable functional monomer; at least one templating compound comprising said analyte; at least one cross-linking agent; and at least one polymerization initiator.

[0047] Preferably, said method comprises bringing said polymerizable mixture into contact with said pre-functionalized filtering device.

[0048] Preferably, said method comprises treating said infrared sensor to polymerize said polymerizable mixture to obtain a cross-linked polymer containing said analyte bonded to said pre-functionalized filtering device.

[0049] Preferably, said method comprises removing said analyte from said cross-linked polymer to obtain a molecularly imprinted polymer bonded to said filtering device and having at least one receptive site for said analyte, so as to obtain an infrared sensor provided with a molecularly imprinted polymeric detection device suitable for detecting a desired analyte.

[0050] In a fourth aspect of the invention, there is provided a method for making an infrared sensor having a molecularly imprinted polymeric detection device for detecting a desired analyte.

[0051] Preferably, said method comprises providing an infrared sensor comprising a detection device intended to be connected to a measuring system to send a detection signal from the detection device to the measuring system, wherein the detection device comprises a sensitive element adapted to receive an input signal and to emit a detection signal in response to the perturbation generated by the input signal, said sensitive element being of the type suitable for detecting infrared radiation emitted by an object located in the field of view of the sensor, and a filtering device operatively connected to the sensitive element and adapted to filter the radiation impinging on the sensitive element so that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength of between about 5 and about 20 pm.

[0052] Preferably, said method comprises treating said filtering device to pre-functionalize said filtering device so as to bind at least one functional group to said filtering device and thereby obtain a pre-functionalized filtering device.

[0053] Preferably, said method comprises preparing a polymerizable mixture comprising: at least one polymerizable functional monomer; at least one template compound comprising said analyte; at least one crosslinking agent; and at least one polymerization initiator.

[0054] Preferably, said method comprises bringing said polymerizable mixture into contact with said pre-functionalized filtering device.

[0055] Preferably, said method comprises treating said infrared sensor so as to polymerize said polymerizable mixture to obtain a crosslinked polymer containing said analyte bound to said pre-functionalized filtering device.

[0056] Preferably, said method comprises removing said analyte from said crosslinked polymer to obtain a molecularly imprinted polymer having at least one recognition site for said analyte, thereby obtaining an infrared sensor provided with a molecularly imprinted polymer detection device suitable for detecting said analyte.

[0057] In a fifth aspect of the invention, there is provided a molecularly imprinted infrared sensor suitable for detecting a desired analyte, comprising a detection device wherein the detection device comprises a sensing element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by the input signal, said sensing element being of the type suitable for detecting infrared radiation emitted by an object located within the field of view of the sensor, and a filtering device operatively connected to said sensing element and configured to filter the radiation impinging upon the sensing element such that the sensing element receives an input signal filtered by said filtering device, said filtering device being configured to filter radiation having a wavelength between about 5 pm and about 20 pm, and wherein said detection device comprises a molecularly imprinted polymer having at least one recognition site for said desired analyte fixed to said filtering device.

[0058] Preferably, said sensor comprises an integrated circuit and said detection device is operatively coupled to said integrated circuit so as to transmit a detection signal from said detection device to the integrated circuit.

[0059] In a sixth aspect of the invention, there is provided a molecularly imprinted infrared sensor suitable for detecting a desired analyte, comprising a detection device comprising a sensing element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by the input signal, said sensing element being of the type suitable for detecting infrared radiation emitted by an object located within the field of view of the sensor, and a filtering device operatively connected to the sensing element and configured to filter the radiation impinging upon the sensing element such that the sensing element receives an input signal filtered by said filtering device, said filtering device being configured to filter radiation having a wavelength between about 5 pm and about 20 pm, and wherein said detection device comprises a molecularly imprinted polymer having at least one recognition site for said desired analyte fixed to said filtering device.

[0060] Preferably, said sensor is configured to be coupled to a measuring system fortransmitting a detection signal from said detection device to said measuring system.

[0061] In a seventh aspect of the invention, there is provided a method for detecting an analyte in a detection environment.

[0062] Preferably, said detection method comprises providing a molecularly imprinted infrared sensor comprising a detection device comprising a sensing element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by the input signal, said sensing element being of the type suitable for detecting infrared radiation emitted by an object located within the field of view of the sensor, and a filtering device operatively connected to the sensing element and configured to filter the radiation impinging upon the sensing element such that the sensing element receives an input signal filtered by said filtering device, said filtering device being configured to filter radiation having a wavelength between about 5 pm and about 20 pm, and wherein said filtering device comprises a molecularly imprinted polymer having at least one recognition site for said desired analyte fixed to said filtering device.

[0063] Preferably, said method comprises positioning said molecularly imprinted infrared sensor in said detection environment such that said analyte can come into contact with said detection device and said analyte can bind to said molecularly imprinted polymer at said at least one recognition site.

[0064] Preferably, said method comprises detecting a detection signal emitted by said detection device as a result of an interaction between said analyte and said molecularly imprinted polymer, in order to detect the presence of said analyte in said detection environment.

[0065] Owing to the invention, it is possible to obtain an infrared sensor suitable for detecting the presence of a desired analyte.

[0066] The sensor of the invention is particularly suitable for detecting a desired analyte in a desired detection environment, in particular in air or even in an aqueous environment.

[0067] Owing to the invention, there is obtained a sensor that is highly reliable in detecting a desired analyte. Furthermore, the sensor is inexpensive and easy to prepare and use.

[0068] Furthermore, a sensor of extremely limited dimensions is obtained, which can be incorporated into a desired analysis system.

[0069] The sensor of the invention is particularly robust and simple to manufacture and use, and does not require special precautions to carry out the detection.

[0070] Furthermore, owing to the invention, there is obtained a sensor capable of performing reliable real-time measurements.

[0071] The molecularly imprinted infrared sensor of the invention enables the detection of the presence of a desired analyte for which the molecularly imprinted polymer has been specifically created. An infrared sensor is thus provided, to which is bound a molecularly imprinted polymer having at least one recognition site adapted to accommodate and bind the desired analyte. When the analyte to be detected is present in the detection environment and comes into contact with the molecularly imprinted polymer of the infrared sensor of the invention, the analyte interacts with the functional groups within a recognition site of the molecularly imprinted polymer and binds reversibly to the molecularly imprinted polymer.

[0072] The molecularly imprinted polymer is chemically bound to the detection device, and in particular to the filtering device of the detection device, so as to be positioned upstream of the sensing element along the path of the radiation reaching the sensing element, whereby the sensing element receives an input signal filtered by the filtering device.

[0073] The radiation passes through the filtering device provided with the molecularly imprinted polymer. If the molecularly imprinted polymer has empty recognition sites, i.e., has not bound the analyte, a certain input signal is generated at the sensing element. Conversely, if the molecularly imprinted polymer has bound the analyte of interest, a different input signal is generated at the sensing element. Thus, depending on whether or not the analyte is bound to the molecularly imprinted polymer, the sensing element receives a different input signal. Accordingly, the presence or absence of the analyte of interest causes a different perturbation of the sensing element. The sensing element, in turn, generates a detection signal dependent on the input signal, or more precisely, on the perturbation induced on the sensing element by the input signal. The sensing element thus generates a detection signal that depends on the presence or absence of the analyte. Such detection signal can be detected by the integrated circuit and transmitted to the measuring system, or transmitted directly to the measuring system.

[0074] Accordingly, the sensing element is reached by an input signal affected by the presence of the analyte of interest. Such variation causes a variation in the temperature of the sensing element, which generates a detection signal measured by suitable measuring systems and dependent on the presence or absence of the analyte of interest.

[0075] The molecularly imprinted polymer is arranged along the path of the radiation reaching the sensing element. The molecularly imprinted polymer is arranged on the filtering device so as to be accessible from the outside, whereby the analyte of interest caninteract and bind with the molecularly imprinted polymer and generate an input signal to the sensing element dependent on the presence of the analyte at the sensing element.

[0076] Furthermore, since the molecularly imprinted polymer is chemically bound to the filtering device, it is firmly anchored to the filtering device and does not tend to detach from the sensor body.

[0077] The pre-functionalization of the filtering element enables the molecularly imprinted polymer to be stably bound to the filtering element. This increases the stability and robustness of the obtained sensor.

[0078] The variation in the detection signal emitted by the sensing element is converted by suitable conversion systems so as to be measurable by measuring systems known in the art and used in infrared sensor detection. In this way, a measurable signal is generated. In some embodiments, the conversion systems may be integrated within the integrated circuit.

[0079] Owing to certain aspects of the invention, it is possible to readily convert an existing infrared sensor into a molecular infrared sensor for detecting the presence of a desired analyte in a desired detection environment.

[0080] Owing to certain aspects of the invention, it is possible to provide a molecular infrared sensor suitable for detecting the presence of a desired analyte in a desired detection environment. Known and reliable technologies can be employed to perform accurate detection of an analyte.

[0081] Owing to the invention, a detection device, and therefore an infrared sensor, is obtained which is highly specific to a desired analyte and thus capable of performing precise and reliable measurements. By varying the template molecule, the type of analyte to be detected with the sensor of the invention can be easily and conveniently modified.

[0082] By appropriately varying the template molecule and thus the configuration of said at least one recognition site of the molecularly imprinted polymer, it is possible to produce an infrared sensor suitable for detecting a desired analyte, or a desired group of analytes.

[0083] The molecularly imprinted infrared sensor thus obtained is reliable and has a low cost.

[0084] Moreover, the molecularly imprinted infrared sensors of the invention can be used and subsequently regenerated and reused countless times. For example, after a first use, the sensors of the invention can be treated so as to remove the analyte from the recognition sites of the molecularly imprinted polymer, thereby regenerating the recognition sites in the molecularly imprinted polymer and thus obtaining, once again, a molecularly imprintedpolymer suitable for binding a desired analyte.

[0085] The molecularly imprinted polymer used in the sensors of the invention is capable of reversibly exchanging the desired analyte for which it has been synthesized, i.e., it is configured to reversibly bind said analyte within its recognition sites and, at the same time, it is configured to change its physical properties depending on the presence of analytes bound to the recognition sites.

[0086] It is thus possible to carry out simple and specific detections.

[0087] The present invention, in at least one of the above-mentioned aspects, may exhibit at least one of the further preferred features described below.

[0088] The molecularly imprinted polymer is chemically bound to the pre-functionalized filtering device, preferably through covalent bonds.

[0089] In this way, the molecularly imprinted polymer is firmly bound to the filtering device and therefore to the sensor structure. This prevents detachment of the molecularly imprinted polymer from the sensor, making the sensor obtained by the method of the invention particularly robust and reliable. Depending on the molecularly imprinted polymer to be used or generated, the type of pre-functionalization of the filtering device is selected so as to optimize the bond between the molecularly imprinted polymer and the filtering device. Conversely, the chemical composition of the molecularly imprinted polymer, or the monomers thereof, can be selected based on the characteristics of the filtering device to optimize the bond between the molecularly imprinted polymer and the filtering device.

[0090] In the present description, a first element is understood to be coupled to a second element when the first element is applied to the second element in direct contact, but also when there is no direct contact between the first and second elements, yet the first and second elements are operatively coupled. In particular, the detection device is coupled to the integrated circuit such that the signal generated by the sensing element reaches the integrated circuit.

[0091] In the present description, a first element is understood to be bound to a second element when a chemical bond is established between the first element and the second element, preferably a covalent chemical bond.

[0092] The term “functional group” is understood to mean a functional group configured to bind to a material, such as the material of the filtering device. The functional group may consist of a single atom or a plurality of atoms bonded together. Preferably, the functional group binds to the material of the filtering device via a covalent bond.

[0093] In the present description, a first element is understood to be positioned“downstream” of a second element along a desired trajectory when, along the oriented line identified by said trajectory, the first element is located in a position subsequent to the position of the second element. Similarly, a first element is understood to be positioned “upstream” of a second element when, along the oriented line identified by said trajectory, the first element is located in a position prior to the position of the second element. In particular, along the trajectory of electromagnetic radiation towards the sensing element of the infrared sensor, the filtering device is positioned upstream of the sensing element, and conversely, the sensing element is positioned downstream of the filtering device such that the radiation, before reaching the sensing element, passes through the filtering device.

[0094] Preferably, said sensing element comprises a sensing element made of a pyroelectric material, that is, a material that generates energy when exposed to heat. Preferably, said sensing element is made of a material selected from the group comprising gallium nitride (GaN), cesium nitrate (CsNO3), or polyvinyl fluoride.

[0095] Preferably, said sensing element is of the TMOS type, that is, a type of infrared sensor consisting of a thermally isolated and micromachined transistor manufactured using CMOS-SOI (silicon-on-insulator) MEMS (micro-electro-mechanical systems) technology.

[0096] In some embodiments, the sensing element comprises an array of floating vacuum thermal MOS (TMOS) transistors interconnected and acting as a single sensing element.

[0097] Preferably, said filtering device comprises a band-pass optical filter configured to transmit towards the sensing element radiation having a wavelength between about 5 micrometres and about 20 micrometres.

[0098] Band-pass optical filters are known in the art and can be made of various materials depending on the desired characteristics.

[0099] Preferably, said filtering device is a multilayer filtering device comprising a plurality of layers superimposed on one another.

[0100] Preferably, said filtering device is a multilayer filtering device comprising at least one support glass layer and a plurality of filtering layers applied to said glass layer.

[0101] In some embodiments, said filtering device comprises at least one layer made of a material selected from Silicon (Si), silicon oxide (SiO2), tantalum oxide (Ta2O5), or niobium oxide (Nb2O5).

[0102] In some embodiments, said filtering device comprises a band-pass optical filter configured to transmit, towards the sensing element, radiation having a wavelength between about 5 micrometres and about 20 micrometres, and a coating layer applied onto said optical filter such that said coating layer is arranged upstream of the optical filter alongthe path of the radiation towards the sensing element. The coating layer serves to protect the optical filter from external agents. Preferably, the coating layer is the outermost layer of the filtering device, and is preferably positioned on an outer portion of said infrared sensor so as to be capable of coming into contact with said analyte.

[0103] In some preferred embodiments, said molecularly imprinted polymer is bound to said coating layer so as to be accessible from the outside and able to bind the analyte of interest. In particular, the recognition site of the molecularly imprinted polymer is accessible from the outside.

[0104] Preferably, said coating layer of said filtering device is an anti-reflective coating layer arranged upstream of the optical filter along the path of the radiation towards the sensing element. This makes it possible to limit or even reduce interference phenomena of the incident light radiation.

[0105] Preferably, said anti-reflective coating layer is made of a material suitable for establishing a covalent bond with said functional group so as to pre-functionalize said coating layer.

[0106] Preferably, said coating layer is made of a material selected from a mineral salt, preferably a metallic salt, such as Zinc Sulfide (ZnS), or a metal oxide, such as Tantalum Oxide (Ta2O5).

[0107] In some preferred embodiments, said anti-reflective coating layer is made of Zinc Sulfide, preferably Zinc Sulfide (ZnS) in crystalline form having the following structure:

[0108] In some embodiments, said filtering device is a multilayer filtering device and comprises a layer made of a silicon-based material arranged so as to constitute the outermost layer of the filtering device. Preferably, said silicon-based material layer is substantially transparent to infrared radiation.

[0109] In some embodiments, said infrared sensor comprises an outer housing intended to enclose said sensing element, and said integrated circuit, if present.

[0110] In some embodiments, said filtering device is arranged on an outer wall of said housing so as to be accessible from the outside.

[0111] In some preferred embodiments, said filtering device comprises an internal filtering device arranged inside said housing and an external filtering device arranged on an outer wall of said housing. Preferably, said external filtering device comprises a filtering element made of a silicon-based material.

[0112] In such embodiment, the molecularly imprinted polymer is bound to one of the internal filtering device or the external filtering device, preferably the molecularly imprinted polymer being bound to the external filtering device so as to be accessible from the outside and able to bind the analyte of interest.

[0113] Preferably, the external filtering device comprises a filtering layer made of a silicon- based material. Preferably, said silicon-based material layer is substantially transparent to infrared radiation.

[0114] In some embodiments, said coating layer of said filtering device is arranged on an outer wall of said housing so as to be accessible from the outside. In this way, by binding the molecularly imprinted polymer to the coating layer, the molecularly imprinted polymer is accessible from the outside, and an analyte in the external environment is free to bind to said molecularly imprinted polymer.

[0115] In some embodiments, said coating layer comprises a layer made of a silicon- based material. In this case, the molecularly imprinted polymer is chemically bound to the layer made of the silicon-based material. In such case, the method comprises prefunctionalizing the coating layer of the filtering device so as to promote the bond between the molecularly imprinted polymer and the coating layer.

[0116] In some embodiments, said sensor is provided with thermal insulation means for thermally insulating said sensing element and avoiding interference in the detection due to the temperature of the external environment.

[0117] Preferably, said infrared sensor comprises an integrated circuit (IC) configured to receive a detection signal from the sensing element of the detection device and provide a digital signal to a measuring system.

[0118] Preferably, said sensing element is integrated within said integrated circuit.

[0119] In some preferred embodiments, said infrared sensor comprises a measuring system.

[0120] In other preferred embodiments, the measuring system is arranged externally to the infrared sensor and operatively connected to the integrated circuit.

[0121] Preferably, the infrared sensor comprises a measuring system for measuring the digital signal produced by the integrated circuit.

[0122] Preferably, said integrated circuit comprises a low-noise amplifier coupled to the detection device and receiving the detection signal from the detection device, converting it into an analogue signal.

[0123] Preferably, said integrated circuit comprises an analogue-to-digital converter (ADC) receiving the analogue voltage signal from the amplifier and converting it into a digital signal.

[0124] Preferably, said sensor comprises a microprocessor operatively coupled to the sensing element.

[0125] Preferably, the analogue-to-digital converter is coupled to a filtering system for filtering the digital signal.

[0126] Preferably, the measuring system comprises a microprocessor, an amplifier for converting the electrical signal from the sensing element into an analogue voltage signal, and an analogue-to-digital converter used to generate the digital information.

[0127] In some embodiments, said sensor comprises a first detection device provided with a first filtering device and a first sensing element coupled to the first filtering device and configured to receive a first input signal filtered by the first filtering device, and a second detection device provided with a second filtering device and a second sensing element coupled to the second filtering device and configured to receive a second input signal filtered by the second filtering device. The first and second sensing elements are both sensing elements adapted to detect infrared radiation emitted by an object located within the field of view of the sensor.

[0128] Preferably, the first and second detection devices are operatively connected to said measuring system. In this way, the measuring system receives a first detection signal from the first sensing element and a second detection signal from the second sensing element. The provision of two sensing elements operatively connected to the measuring system makes it possible to increase the accuracy of the detection performed.

[0129] Preferably, the first and second sensing elements are connected to the measuring system via the integrated circuit.

[0130] In some embodiments, said sensor comprises a first detection device provided with a first filtering device and a first sensing element coupled to the first filtering device and configured to receive a first input signal filtered by the first filtering device, and a second detection device provided with a second filtering device and a second sensing element coupled to the second filtering device and configured to receive a second input signal filtered by the second filtering device. The first and second sensing elements are bothsensing elements adapted to detect infrared radiation emitted by an object located within the field of view of the sensor.

[0131] Preferably, the first detection device and the second detection device are operatively connected to the integrated circuit. In this way, the integrated circuit receives detection signals coming from both the first sensing element and the second sensing element.

[0132] Preferably, the first filtering device is provided with a molecularly imprinted polymer bound thereto, whereas the second filtering device is devoid of the molecularly imprinted polymer. The first sensing element emits a detection signal filtered by the first filtering device and affected by the possible presence of the analyte of interest. The second sensing element emits a detection signal filtered by the second filtering device and unaffected by the presence of the analyte of interest. The first sensing element is intended to receive an input signal perturbed by the binding of the analyte of interest to the molecularly imprinted polymer and thus by the presence or absence of the analyte of interest. The second sensing element receives an input signal that is not influenced by the binding of the analyte to the molecularly imprinted polymer and thus by the presence or absence of the analyte of interest.

[0133] The first sensing element generates a first detection signal that depends on the presence of the analyte of interest. The second sensing element generates a second detection signal that does not depend on the presence of the analyte of interest.

[0134] The provision, in the sensor of the invention, of a first detection device influenced by the presence of the analyte of interest and a second detection device not influenced by the presence or absence of the analyte of interest in the detection environment, makes it possible to increase the accuracy of the detection carried out with the sensor of the invention. In particular, this makes it possible to obtain a detection that is not influenced by boundary conditions, by the conditions of the detection environment, and in particular by the irradiation of bodies in the FOV of the detection environment.

[0135] In some embodiments, the integrated circuit receives a first detection signal generated by the first sensing element, which is affected by the presence of the analyte of interest, and a second detection signal from the second sensing element, which is not affected by the presence of the analyte of interest in the detection environment.

[0136] In some embodiments, the integrated circuit is configured to process the first and second detection signals received from the first and respectively from the second sensing element and to output a differential detection signal. This avoids the measurement signalbeing influenced by the boundary conditions of the measurement environment. It also avoids the measurement conditions influencing the measured signal.

[0137] In some embodiments, the measuring system receives a first detection signal from the first sensing element, which is affected by the conditions of the detection environment and in particular by the presence of the analyte to be detected, and a second detection signal that is unaffected by the presence or absence of the analyte of interest in the detection environment.

[0138] In some embodiments, the measuring system is configured to compare the first detection signal and the second detection signal, obtaining a differential detection signal for detecting the presence of the desired analyte.

[0139] In some embodiments, the measuring system is configured to calculate a difference between the first detection signal and the second detection signal, generating a differential signal that depends on the presence or absence of a desired analyte in the detection environment. The differential signal is unaffected by the temperature or, in general, by the conditions of the detection environment. Interference phenomena on the generated signal are thereby limited.

[0140] In some embodiments, provision is made to send the first detection signal and the second detection signal to a processing system. The external processing system processes the first and second detection signals to generate a differential signal that depends on the presence or absence of a desired analyte in the detection environment.

[0141] Preferably, the integrated circuit is operatively connected to the first and second sensing elements so as to receive the first detection signal emitted by the first sensing element and the second detection signal emitted by the second sensing element, and to convert the first and second detection signals respectively into a first and a second electrical signal suitable for being measured by an appropriate measuring system to which the sensor can be connected, and to send said first and second electrical signals to said measuring system.

[0142] In some embodiments, the sensor comprises a comparator for comparing the first and second detection signals and calculating a difference between the first and second signals. In this way, the sensor sends a differential signal to the measuring system.

[0143] Preferably, the method comprises detecting a first detection signal from the first sensing element, detecting a second detection signal from said second sensing element, and comparing said first detection signal and said second detection signal.

[0144] Preferably, said method comprises calculating a differential detection signal fromthe first detection signal and the second detection signal.

[0145] Preferably, said method comprises calibrating said molecularly imprinted infrared sensor. Preferably, said calibrating comprises calibrating said sensor at specific detection temperatures to calibrate the operation of the sensor at said specific detection temperatures.

[0146] Preferably, said calibrating comprises a calibration step to convert the 16-bit ADC signal into the molecular concentration of an analyte.

[0147] Preferably, said detection method comprises providing a second molecularly imprinted infrared sensor comprising a second detection device comprising a second sensing element configured to receive a second input signal and to emit a second detection signal in response to a perturbation generated by said second input signal, said second sensing element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of the second sensor, and a second filtering device operatively connected to the second sensing element and configured to filter the radiation impinging upon the second sensing element such that said second sensing element receives a second input signal filtered by said second filtering device, said second filtering device being configured to filter radiation having a wavelength between about 5 pm and about 20 pm, and wherein said second filtering device is devoid of a molecularly imprinted polymer.

[0148] Preferably, said method comprises positioning said second molecularly imprinted infrared sensor in said detection environment.

[0149] Preferably, said method comprises detecting a first detection signal emitted by said first molecularly imprinted infrared sensor, and further detecting said second detection signal emitted by said second infrared sensor.

[0150] Preferably, said method comprises comparing said first detection signal and said second detection signal.[000151] Preferably, said method comprises, after applying to said pre-functionalized filtering device a molecularly imprinted polymer (MIP), subjecting said sensor to a crosslinking phase so as to bind said molecularly imprinted polymer to said filtering device or to said coating layer of the filtering device.[000152] In this manner, the formation of chemical bonds is caused between said prefunctionalized filtering device and the molecularly imprinted polymer.[000153] Preferably, said binding comprises forming chemical bonds, more preferably covalent chemical bonds, between said pre-functionalized filtering device and saidmolecularly imprinted polymer.[000154] Preferably, said binding comprises forming chemical bonds, more preferably covalent chemical bonds, between said pre-functionalized coating layer and said molecularly imprinted polymer.[000155] Preferably, said crosslinking phase enables the formation of covalent bonds between the pre-functionalized coating layer and the molecularly imprinted polymer or between the pre-functionalized sensitive material and the molecularly imprinted polymer.[000156] The molecularly imprinted polymer is therefore stably bound to the sensor.[000157] In some preferred embodiments, said contacting of said polymerizable mixture with said pre-functionalized filtering device or with said pre-functionalized coating layer comprises immersing said pre-functionalized filtering device, or said pre-functionalized coating layer, in said polymerizable mixture.[000158] In some preferred embodiments, said contacting of said polymerizable mixture with said pre-functionalized filtering device or with said pre-functionalized coating layer comprises applying said polymerizable mixture onto said pre-functionalized filtering device, or onto said pre-functionalized coating layer.[000159] In some preferred embodiments, said contacting of said polymerizable mixture with said pre-functionalized filtering device or with said pre-functionalized coating layer comprises depositing said polymerizable mixture onto said pre-functionalized coating layer, or onto said pre-functionalized coating layer.[000160] Preferably, said depositing comprises depositing a film of said polymerizable mixture onto said pre-functionalized filtering device, or onto said pre-functionalized coating layer.[000161] Preferably, said depositing comprises spraying said polymerizable mixture onto said pre-functionalized filtering device, or onto said pre-functionalized coating layer.[000162] In some preferred embodiments, said depositing may be carried out by dropcoating, spraying, dipping, or spin coating.[000163] Preferably, said method comprises forming a layer of molecularly imprinted polymer having a thickness of at least 0.1 pm, more preferably between about 0.15 pm and about 5 pm, even more preferably between about 0.5 pm and about 3 pm, and most preferably a thickness of about 2 pm.[000164] In some preferred embodiments, said pre-functionalizing comprises treating said filtering device with a reactive compound so as to bind said functional group to said filtering device.[000165] In some preferred embodiments, said pre-functionalizing comprises treating said coating layer with a reactive compound so as to bind said functional group to said coating layer.[000166] In some preferred embodiments, said pre-functionalizing comprises treating said filtering device with a reactive compound so as to bind said functional group to said filtering device.[000167] In some preferred embodiments, said pre-functionalizing comprises treating said coating layer of said filtering device with a reactive compound so as to bind said functional group to said filtering device.[000168] In some preferred embodiments, said functional group comprises a phenyl group (-CeHs).[000169] In some preferred embodiments, said functional group comprises a halogen atom, preferably chlorine or bromine.[000170] In some preferred embodiments, said functional group comprises a phenyl group (-CeHs) to which a halogen atom, preferably chlorine or bromine, is bound.[000171] Preferably, said reactive compound is a compound containing a halogen atom. In this way, it is possible to bind a halogen atom to said filtering device or to said coating layer of said filtering device element.[000172] In some preferred embodiments, said reactive compound is a mercaptan, preferably a halogenated mercaptan, preferably selected from compounds having the formula SH-(CeH5)-CI or SH-(CeH5)-Br.[000173] Preferably, the halogen atom is bound in the para position of the phenyl ring of the mercaptan.[000174] In some preferred embodiments, the reactive compound is 4-chlorothiophenol having the formula:Chemical Formula 1[000175] In some preferred embodiments, the reactive compound is 4-bromothiophenol having the formula:Chemical Formula 2[000176] Preferably, said pre-functionalizing comprises treating said filtering device with a reactive compound to bind at least one halogen atom to said filtering device.[000177] Preferably, said pre-functionalizing comprises treating said coating layer of said filtering device with a reactive compound having the general formula R-Si-Xa, such as, for example, trimethoxyvinylsilane or triethoxyvinylsilane.[000178] Preferably, said coating layer is made of a metallic salt, more preferably zinc sulfide (ZnS).[000179] In some preferred embodiments, said pre-functionalizing comprises creating sulfide (SS) bridges between said coating layer and said thiol.[000180] In some preferred embodiments, said reactive compound is a mercaptan, preferably a halogenated mercaptan, preferably selected from compounds having the formula SH-(C6H5)-CI or SH-(CeH5)-Br.[000181] Preferably, said coating layer is made of a metallic oxide, preferably tantalum pentoxide (Ta2Os).[000182] In some preferred embodiments, said reactive compound is a silane and said prefunctionalizing comprises creating silane (-Si-) bridges between said coating layer and said silane. The coating layer is preferably made of a silicon-based material.[000183] In some preferred embodiments, said analyte is a protein.[000184] Preferably, said molecularly imprinted polymer comprises at least one binding site configured to receive at least one protein, preferably a viral surface protein.[000185] In some preferred embodiments of the invention, the virus belongs to the family Coronaviridae.[000186] In some preferred embodiments, the virus is of the type SARS-CoV.[000187] In some preferred embodiments, the virus is SARS-CoV-2.[000188] In some preferred embodiments, the surface protein has a mass between 10 and 500 kDa, preferably between 50 and 200 kDa.[000189] In some preferred embodiments, said analyte is bovine serum albumin (BSA).[000190] In some preferred embodiments, said molecularly imprinted polymer is obtained from the polymerization of a polymerizable mixture comprising: at least one polymerizable functional monomer; at least one template comprising said analyte; at least one crosslinking agent; at least one polymerization initiator.[000191] Preferably, said at least one functional monomer is a monomer having at least one functional group capable of specifically interacting with said analyte to be detected and at least one polymerizable functional group.[000192] In some preferred embodiments, said at least one functional monomer comprises one or more of the following functional groups: carbonyl group, hydroxyl group, and amino group. These functional groups are particularly suitable for interacting, by means of hydrogen bond formation, with various regions of the surface proteins.[000193] In some preferred embodiments, said at least one functional monomer comprises at least two different groups selected from the above-mentioned functional groups, more preferably all three.[000194] Preferably, said polymerizable mixture comprises a first functional monomer and a second functional monomer.[000195] In some preferred embodiments, said template molecule is a protein.[000196] In some preferred embodiments, said template molecule is a viral protein.[000197] Preferably, said method comprises polymerizing said mixture to obtain a crosslinked polymer containing said template.[000198] Preferably, said method comprises removing said template to obtain a crosslinked molecularly imprinted polymer having at least one recognition site for said analyte.[000199] Preferably, said polymerizable mixture further comprises at least one radical polymerization initiator and a polymerization accelerator.[000200] In some preferred embodiments, said at least one monomer has the general formula:CH2-CR!-CO-NHR2( Chemical Formula 3) where:Ri is H or CH3;R2is selected from: H or a Ci-C8alkyl, preferably a C!-C4alkyl, linear or branched.[000201] In certain preferred embodiments, in Chemical Formula 3, R2 is H.[000202] In another preferred embodiment, in Chemical Formula 3, R2 is a Ci-Cs alkyl group, preferably a C1-C4 alkyl group, either linear or branched. The presence of this alkylgroup imparts to the functional monomer a non-polar portion capable of interacting with the non-polar regions of proteins.[000203] In certain preferred embodiments, the polymerizable mixture comprises at least one monomer of general formula:CH2= CRI -CO-O-(CH2-CH2-O)n-H ( Chemical Formula 4) where:Ri is H or CH3; n is an integer in the range 1-4, preferably in the range 1-2.[000204] In certain preferred embodiments, the polymerizable mixture comprises at least one monomer of Formula 3 and at least one monomer of Formula 4. In such case, the molar ratio between the monomers of Formula 3 and those of Formula 4 is preferably within the range from 5:1 to 1 :5, more preferably from 4:1 to 1 :1 , and even more preferably from 3:1 to 1.5:1.[000205] In certain preferred embodiments, the polymerizable mixture comprises acrylamide, N-tert-butylacrylamide, and 2-hydroxyethyl methacrylate.[000206] The crosslinking agent is a molecule having at least two functional groups capable of polymerizing with the at least one functional monomer of the polymerizable mixture. For this purpose, crosslinking agents known in the art may be employed, such as, for example, N,N'-methylenebisacrylamide, polyethylene glycol dimethacrylate, divinylbenzene, and 3- (acryloyloxy)-2-hydroxypropyl methacrylate.[000207] In certain preferred embodiments, the crosslinking agent is N,N'- methylenebisacrylamide.[000208] The radical polymerization initiator is of a type known to the person skilled in the art. Preferably, the initiator is selected from initiators capable of polymerizing the monomers of the polymerizable mixture at a temperature within the range from 0 °C to 40 °C, preferably from 15 °C to 30 °C. At such temperature, the polymerization reaction proceeds to the formation of the molecularly imprinted polymer without altering the surface protein used as template.[000209] In certain preferred embodiments, the radical polymerization initiator comprises persulfate ions and N,N,N',N'-tetramethylethylenediamine (TMED). Alternatively, other peroxide-based Red-Ox initiator pairs may be employed.[000210] The polymerizable mixture may further comprise water or, more preferably, a buffer solution capable of maintaining the pH at a desired value according to the protein used as template, generally within the range of pH 6-8. In one embodiment, the buffersolution is a phosphate buffer having preferably a pH of about 7. The relative amounts of the above-mentioned components in the polymerization mixture may vary over wide ranges.[000211] In certain preferred embodiments, the total concentration of functional monomer is in the range of 0.0001-0.100 M, preferably in the range of 0.001-0.050 M.[000212] In certain preferred embodiments, the total concentration of template in the monomeric mixture is in the range from 1 X10-8M to 5x10"3M, preferably in the range from 4x10’7M to 7x10’4M.[000213] In certain preferred embodiments, the total concentration of crosslinker in the monomeric mixture is in the range from 0.05 M to 1.0 M, preferably in the range from 0.1 M to 0.5 M.[000214] In certain preferred embodiments, the total concentration of polymerization initiator in the monomeric mixture is in the range from 0.03% w / v to 0.15% w / v.[000215] In certain preferred embodiments, the polymerizable mixture may be prepared by mixing the selected functional monomer or functional monomers in water or, more preferably, in a buffer solution, preferably together with the protein or proteins to be detected, the crosslinking agent, and the polymerization initiator.[000216] To obtain the molecularly imprinted polymer according to the invention, the polymerization reaction may be carried out by one of the polymerization methods known to the skilled person, such as, for example: precipitation polymerization, suspension polymerization, emulsion polymerization, and dispersion polymerization.[000217] In certain preferred embodiments, said polymerization step is carried out after said contacting of said polymerizable mixture with the pre-functionalized filtering device or the pre-functionalized coating layer. In this way, the polymerization of the molecularly imprinted polymer occurs and a bond is formed between the molecularly imprinted polymer and the pre-functionalized filtering device or the pre-functionalized coating layer of the infrared sensor.[000218] In certain preferred embodiments, the polymerization step of the polymerizable mixture is carried out at a temperature within the range of 15 °C-30 °C.[000219] The duration of the polymerization reaction depends on several factors, including the amount of polymerizable mixture deposited. In general, the polymerization duration is within the range of 3-20 minutes.[000220] In certain preferred embodiments, said thin film is applied onto said prefunctionalized coating layer.[000221] In certain preferred embodiments, said thin film is applied onto said prefunctionalized filtering device.[000222] In certain preferred embodiments, said method comprises applying said molecularly imprinted polymer (MIP) having at least one binding site for a desired analyte onto at least a portion of said pre-functionalized coating layer.[000223] In certain preferred embodiments, said method comprises applying said molecularly imprinted polymer (MIP) having at least one binding site for a desired analyte onto at least a portion of said pre-functionalized coating.[000224] Preferably, said binding is carried out after said applying. In this case, a crosslinking step is performed subsequent to the application step so as to cause the formation of bonds between the pre-functionalized coating layer and the molecularly imprinted polymer or between the pre-functionalized sensitive material and the molecularly imprinted polymer.[000225] Preferably, said binding comprises subjecting said molecularly imprinted polymer (MIP) on said pre-functionalized polymeric material or on said pre-functionalized coating to crosslinking in order to bond said molecularly imprinted polymer (MIP) to said prefunctionalized polymeric material or to said pre-functionalized coating.[000226] Once the crosslinked polymer containing the template has been obtained, said template is removed to obtain a molecularly imprinted polymer having at least one binding site for said analyte bound to said polymeric material, thereby obtaining a polymeric material having at least one binding site capable of interacting with molecules of said analyte.[000227] In certain preferred embodiments, said removal step may be carried out by treating the crosslinked polymer containing the template with an aqueous solution containing a proteolytic enzyme (protease), for example trypsin, followed by washing with water. Such embodiment is particularly advantageous when the template is a protein.[000228] The washing water may optionally contain at least one surfactant (for example sodium dodecyl sulfate, SDS).[000229] Preferably, said detection method comprises regenerating said detection device to remove said analyte from said at least one binding site of said molecularly imprinted polymer so as to free said at least one binding site of said molecularly imprinted polymer.[000230] Preferably, said method further comprises detecting said analyte again after said regenerating with said molecularly imprinted infrared sensor.[000231] In this way, the same sensor can be used multiple times to detect the same typeof analyte. The regeneration step is similar to the template removal step in the preparation of the molecularly imprinted polymer and is therefore known in the art. The reactions involved in the regeneration step depend on the nature of the analyte to be removed and / or on the characteristics of the molecularly imprinted polymer employed.[000232] It is noted that some steps of the above-described methods may be independent of the execution order reported. Furthermore, some steps may be optional. Moreover, some steps of the methods may be repeated, or may be carried out in series or in parallel with other steps of the method.[000233] Preferably, a calibration step is provided to calibrate the detection of the sensors of the invention.[000234] The features and advantages of the invention will become more apparent from the detailed description of certain preferred embodiments thereof, provided by way of nonlimiting example, wherein:Figure 1 is a graph showing a detection signal of a sensor according to one embodiment of the invention.[000235] Certain particular embodiments of certain steps of the methods of the invention, which may be employed to manufacture the sensors of the invention, are now explained in detail.EXAMPLE 1PREPARATION OF AN INFRARED SENSOR WITH MOLECULARLY IMPRINTED POLYMER[000236] To manufacture a molecularly imprinted infrared sensor, an infrared sensor of the TMOS type is first provided, for example the SHTS221 sensor from STMicroelectronics. STHS34PF80 is an infrared sensor that can be used to detect the presence of objects. This sensor measures the IR radiation of the object using TMOS technology to detect its presence.[000237] An infrared sensor is provided comprising a housing, and a detection device comprising a filtering device provided on said housing and a sensing element coupled to the first filtering device and configured to receive a first input signal filtered by the first filtering device. The sensing element is a sensing element suitable for detecting infrared radiation emitted by an object located within the field of view of the sensor itself; in particular, the sensing element is of the TMOS type.[000238] The first filtering device is configured to filter radiation having a wavelength between about 5 and about 20 pm so that only the radiation having such wavelengthreaches the sensing element.[000239] The sensing element receives an input signal filtered by the filtering device and emits a detection signal. The sensing element is operatively connected to an integrated circuit that receives the detection signal and is configured to convert the detection signal into an electrical signal suitable for being measured by an appropriate measuring system to which the sensor can be connected.[000240] The integrated circuit also implements dedicated intelligent processing to detect / discriminate between stationary and moving objects and can activate dedicated interrupts. Several ODRs from 0.25 Hz to 30 Hz and a one-shot mode are available. STHS34PF80 is equipped with a 3-wire l2C / SPI interface and is housed in a 3.2 * 4.2 * 1.455 mm OLGA 10L package compatible with SMD mounting.[000241] The filtering device is arranged on the outer wall of the sensor housing and is configured as a window provided on the housing.[000242] The filtering device is configured so that the sensor has a field of view of about 80°.[000243] The filtering device is a multilayer filtering device comprising a first filtering layer intended to filter the incoming electromagnetic radiation towards the sensing element, on which an anti-reflective coating layer is applied. The anti-reflective coating layer is arranged externally so as to form the outermost layer of the filtering device. The coating layer is positioned upstream of the filtering element in the path towards the respective sensing element. The anti-reflective coating layer prevents diffuse electromagnetic radiation from creating a disturbance on the filtering device. The anti-reflective coating layer is made of zinc sulfide (ZnS). Such anti-reflective compound is usually employed when the useful wavelength window falls between one micron and several tens of microns, as in the case of infrared radiation. In other embodiments, anti-reflective compounds other than zinc sulfide may be provided.[000244] A solution of methanol with a halogenated mercaptan, in particular with 4- chlorothiophenol, was prepared.[000245] The 4-chlorothiophenol: methanol solution (40 mg / mL) is kept in contact with the coating layer of the filtering device for 12 h at a temperature of 45 °C so as to promote a reaction of the thiophenol with the zinc sulfide. As a result of this reaction, a prefunctionalized coating layer is generated in which the sulfur atom is bound to the zinc sulfide layer and to the benzene ring. The chlorine atom remains on the outside and is available to be substituted in the subsequent step of specific receptor growth on the surface, asexplained hereinafter.[000246] A filtering device is thus formed having a pre-functionalized coating layer whose structure is schematically represented in the following Chemical Formula 5Chemical Formula 5, wherein A denotes a chlorine atom or a bromine atom.[000247] At the end of the treatment, any residues are removed by cold methanol washing. Methanol has shown high solvent power for the selected halogenated compounds, is easily available, and has a limited cost. This solvent has also shown high compatibility with the components of the polymerizable mixture used to prepare the molecularly imprinted polymer. Moreover, this solvent has a very low water content, since thiol is poorly soluble in water and would precipitate during treatment with significant water content. These characteristics make it possible to obtain both a good reaction yield and to protect the sensor at the same time.[000248] The pre-functionalization reaction generates sulfide (-S) bridges between the thiol and the oxide of the coating layer. The thiol molecule is positioned so that the sulfur is bound to the material of the coating layer and the benzene ring, to which the halogen atom is bound, is arranged externally. In particular, the halogen atom is arranged externally and can form further bonds. Specifically, the halogen atom can be substituted.[000249] Subsequently, the surface of the pre-functionalized coating layer is immersed in a desired monomer mixture in the presence of reaction initiators. The surface of the coating must be covered by the monomer mixture. The surface of the coating is kept in contact with the monomer mixture for at least 10 minutes so as to allow the growth of the molecularly imprinted polymer.[000250] Ammonium persulfate with the addition of a base (N,N,N',N'- tetramethylethylenediamine) is used so as to generate a redox reaction with the prefunctionalized coating. The reaction is initiated at room temperature in an aqueousenvironment. In general, the reaction processes involved are known to those skilled in the art. With the initiation of the crosslinking reaction, substitution of the halogen occurs with simultaneous growth of the polymer on the pre-functionalized surface.[000251][000252] Under the reaction conditions, uniform growth of the polymer bound to the coating layer is obtained, forming a polymer layer having a thickness between about 0.5 pm and about 3 pm, capable of binding the analyte of interest and creating measurable perturbations with the electronic device.[000253] A sensor is thus obtained having a filtering device to which a molecularly imprinted polymer suitable for binding a desired analyte is bound.[000254] The sensor thus obtained is then thoroughly washed with water to remove any unreacted monomer residues.[000255] Finally, the template molecule is removed from the prepared polymer, namely the template molecule chosen for the synthesis of the receptor. This template extraction process is known and described in the prior art.EXAMPLE 2PREPARATION OF AN INFRARED SENSOR WITH MOLECULARLY IMPRINTED POLYMER[000256] An infrared sensor with molecularly imprinted polymer was prepared starting from the same sensor used in Example 1. In the pre-functionalization step, 4-bromothiophenol was used instead of 4-chlorothiophenol.[000257] In this case as well, the 4-bromothiophenol:methanol solution (40 mg / mL) is kept in contact with the surface to be treated for 12 h at a temperature of 45 °C to promote a reaction of the thiophenol with the zinc sulfide and the pre-functionalization of the coating layer. As a result of this reaction, the sulfur atom is bound to the zinc sulfide layer and to the benzene ring, while the bromine atom remains on the outside and is available to be substituted in the subsequent step of polymer growth on the pre-functionalized coating layer surface, as described hereinafter. A pre-functionalized substrate is formed, the structure of which is schematically represented in Formula 5.[000258] Subsequently, the procedure described in Example 1 is followed, immersing the sensors in contact with a monomer mixture in the presence of reaction initiators. The coating surface must be covered by the monomer mixture. The coating surface is kept in contact with the monomer mixture for at least 10 minutes to allow the growth of the molecularly imprinted polymer. In this case as well, growth of a homogeneous polymer layeris obtained, having a thickness between about 0.5 m and about 3 pm. The polymeric material contains the template molecule, which is subsequently extracted to leave cavities in the molecularly imprinted polymer so that the polymer can bind the analyte of interest. A sensor is thus obtained having a filtering device to which a molecularly imprinted polymer suitable for binding a desired analyte is bound.EXAMPLE 3PREPARATION OF AN INFRARED SENSOR WITH MOLECULARLY IMPRINTED POLYMER[000259] An infrared sensor as used in Example 1 is treated, and the coating layer of the filtering device is pre-functionalized as described in Example 1 or Example 2. Subsequently, a molecularly imprinted polymer suitable for binding a desired analyte is deposited onto the pre-functionalized coating layer. Thereafter, the molecularly imprinted polymer is subjected to a crosslinking reaction so as to bind said molecularly imprinted polymer to said prefunctionalized coating layer, thereby obtaining an infrared sensor provided with a molecularly imprinted polymer fixed to the coating layer of the filtering device. Where present, the template molecule is removed from the molecularly imprinted polymer.EXAMPLE 4PREPARATION OF AN INFRARED SENSOR WITH MOLECULARLY IMPRINTED POLYMER[000260] To produce a further molecularly imprinted infrared sensor according to the invention, an infrared sensor of the TMOS type is first provided.[000261] An infrared sensor is provided comprising a housing, and a first detection device comprising a first filtering device provided on said housing and a first sensing element coupled to the first filtering device and configured to receive a first input signal filtered by the first filtering device, and a second detection device comprising a second filtering device provided on said housing and a second sensing element coupled to the second filtering device and configured to receive a second input signal filtered by the second filtering device. The first and second sensing elements are both sensing elements suitable for detecting infrared radiation emitted by an object located within the field of view of the sensor itself. The first sensing element and the second sensing element are both TMOS-type sensing elements.[000262] The first and second filtering devices are configured to filter radiation having a wavelength between about 5 and about 20 pm so that only radiation having such wavelength reaches the first and the second sensing element.[000263] The first sensing element receives a first input signal filtered by the first filtering device and emits a first detection signal. The second sensing element receives a second input signal filtered by the second filtering device and emits a second detection signal. The first sensing element and the second sensing element are operatively connected to the integrated circuit that receives the first and second detection signals. The integrated circuit is configured to convert the detection signal into an electrical signal suitable for being measured by an appropriate measuring system to which the sensor can be connected.[000264] The integrated circuit also implements dedicated intelligent processing to detect / discriminate between stationary and moving objects and can activate dedicated interrupts. Several ODRs from 0.25 Hz to 30 Hz and a one-shot mode are available. STHS34PF80 is equipped with a 3-wire l2C / SPI interface and is housed in a 3.2 x 4.2 x 1.455 mm OLGA 10L package compatible with SMD mounting.[000265] The first and second sensing elements are positioned within the housing so as not to be directly exposed to electromagnetic radiation. The first and second filtering devices are arranged on the outer wall of the sensor housing and are configured as windows provided on the housing. The first and second devices allow the passage of radiation solely towards the first and second sensing elements, respectively.[000266] The first and second filtering devices are configured so that the sensor has a field of view of about 80°.[000267] Each filtering device comprises a first filtering layer intended to filter the incoming electromagnetic radiation towards the respective sensing element, on which an anti- reflective coating layer is applied. The anti-reflective coating layer is arranged externally so as to form the outermost layer of the filtering device. The coating layer is positioned upstream of the filtering element in the path towards the respective sensing element.[000268] The anti-reflective coating layer prevents diffuse electromagnetic radiation from creating a disturbance on the filtering device.[000269] The anti-reflective coating layer is made of zinc sulfide (ZnS). Such anti-reflective compound is usually employed when the useful wavelength window falls between one micron and several tens of microns, as in the case of infrared radiation. In other embodiments, anti-reflective compounds other than zinc sulfide may be provided.[000270] The first and second detection devices are identical to each other.[000271] A pre-functionalization solution of methanol with a halogenated mercaptan, 4- chlorothiophenol as in Example 1 or 4-bromothiophenol as in Example 2, is prepared.[000272] The procedure described in Example 1 is followed to functionalize the coatinglayer of the first filtering device, avoiding contact between the pre-functionalization solution and the second filtering device.[000273] A first filtering device is thus obtained having a pre-functionalized coating layer in which the sulfur atom is bound to the zinc sulfide layer and to the benzene ring, while the chlorine atom remains on the outside and is available to be substituted in the subsequent step of specific receptor growth on the surface, as described hereinafter.[000274] A first filtering device is formed having a pre-functionalized coating layer whose structure can be schematically represented by Formula 5 above.[000275] At the end of the treatment, any residues are removed by cold methanol washing. [000276] Subsequently, the surface of the pre-functionalized coating layer is immersed in a desired monomer mixture in the presence of reaction initiators. The coating surface must be covered by the monomer mixture. The coating surface is kept in contact with the monomer mixture for at least 10 minutes to allow the growth of the molecularly imprinted polymer. At this stage, contact between the monomer mixture and the second filtering device is avoided.[000277] Under the reaction conditions, uniform polymer growth is obtained, resulting in a polymer layer suitable for binding an analyte of interest and for generating, upon analyte binding, a perturbation in the input signal to the first sensing element that is measurable. These reactions are carried out without affecting the second filtering device.[000278] A sensor is thus obtained having a first filtering device to which a molecularly imprinted polymer is bound, and a second filtering device without a molecularly imprinted polymer. The first and second detection devices of the sensor differ solely in the presence of the molecularly imprinted polymer on the first filtering device.[000279] The sensor thus obtained is then thoroughly washed with water to remove any unreacted monomer residues.[000280] Finally, the template molecule is removed from the prepared polymer, namely the template molecule chosen for the synthesis of the receptor. This template extraction process is known and described in the prior art.EXAMPLE 5PREPARATION OF A MOLECULARLY IMPRINTED POLYMER[000281] A molecularly imprinted polymer to be used in the sensors of the invention is prepared. Methods and mixtures for producing molecularly imprinted polymers are known in the prior art. By varying the template molecule according to the analyte to be detected, polymers specifically suitable for binding a particular analyte are obtained.[000282] A polymerization mixture is prepared by mixing the following functional monomers and crosslinking agent in phosphate buffer (pH = 7.4, concentration 15 mM): acrylamide 0.01876 M, N-tert-butylacrylamide (TBAm) 0.008736 M, 2-hydroxyethyl methacrylate 0.0111 M, N,N'-methylenebisacrylamide 0.1874 M. The monomers are purchased from Sigma Aldrich, Darmstadt, Germany.[000283] The polymerization mixture (10 mL) is prepared at room temperature with the aid of an ultrasonic bath and degassed with nitrogen gas. The protein of interest is then added to the mixture in an amount of 1 * 10"6M. The protein used for the preparation is BSA (Bovine Serum Albumin, CAS 9048-46-8) produced by Sigma Aldrich (Darmstadt, Germany).[000284] To initiate the polymerization reaction at room temperature, 10 pL of N,N,N',N'- tetramethylethylenediamine (0.06% v / v) and ammonium persulfate (0.08% w / v) are added to the mixture.[000285] The mixture is immediately used and deposited onto the pre-functionalized coating layer, for example as explained in Example 1 , 2 or 3, and subjected to a polymerization reaction to obtain a crosslinked polymer bound to the previously prefunctionalized coating layer. The mixture is applied to the coating layer so that the latter is immersed in the polymerization mixture. Upon contact with the polymer mixture, the chlorine atom detaches from the pre-functionalized coating, allowing the monomer mixture to bind to the pre-functionalized coating layer.[000286] In this way, the molecularly imprinted polymer is grown directly on the prefunctionalized coating layer and is bound thereto.[000287] Alternatively, the polymerization reaction of the polymerizable mixture may be carried out in a dedicated reaction environment to obtain a molecularly imprinted polymer containing the template. Subsequently, the obtained molecularly imprinted polymer is applied to the pre-functionalized coating layer. In this case, after application, the molecularly imprinted polymer is subjected to a crosslinking reaction to bind it to the pre-functionalized coating layer.[000288] After binding the molecularly imprinted polymer to the pre-functionalized coating layer, the template is removed from the polymer chain to obtain a molecularly imprinted polymer bound to the substrate and provided with cavities suitable for binding the template. EXAMPLE 6METHOD FOR PRODUCING A MOLECULARLY IMPRINTED THERMAL SENSOR WITH A SILICON OXIDE (SiO2)-BASED COATING LAYER[000289] The coating layer is treated so as to make the silicon oxide of the sensing element accessible from the outside.[000290] The silicon oxide (SiO2) surface is repeatedly washed with acetone to remove any impurities that could compromise subsequent reactions.[000291] The sensor is immersed in a container containing anhydrous ethanol and a functionalizing reagent having the general formula R-Si-X3, such as trimethoxyvinylsilane or triethoxyvinylsilane, as shown in the following scheme.wherein R is a vinyl radical -CH=CH2.The ratio between the functionalizing reagent and ethanol is about 20:80. Such reagents are added under anhydrous conditions, in the absence of water, preferably under anhydrous argon or nitrogen atmosphere. The reaction is conducted in a sealed environment at a temperature of about 80 °C for about 12 hours. After this period, the sensors are washed with ethanol to remove any impurities or residues.[000292] At the end of the reaction, a sensor is obtained having a pre-functionalized coating layer in which the silicon oxide is bound via silane groups to vinyl groups, as schematically shown below.[000293] After pre-functionalizing the silicon oxide, sensors are obtained having a prefunctionalized coating layer suitable for binding to a molecularly imprinted polymer.[000294] Such sensors can then be brought into contact with a polymerizable mixture suitable for obtaining a desired molecularly imprinted polymer.[000295] Alternatively, a molecularly imprinted polymer can be applied onto the prefunctionalized coating layer and the sensor subsequently subjected to crosslinking to bind the molecularly imprinted polymer to the coating layer.MEASUREMENT TESTS[000296] Experimental trials were conducted to assess the detection effectiveness and operational reliability of the sensors obtained according to the present invention.[000297] For this purpose, sensors were prepared as described in EXAMPLES 1-3, employing a monomer mixture as outlined in EXAMPLE 5, with BSA protein serving as the template molecule for the molecularly imprinted polymer (MIP). A sensor was thereby obtained, comprising a detection device incorporating a MIP specifically designed to detect the presence of BSA, the MIP being bound to the detection device of the sensor and, in particular, to the coating layer of the sensor. The resulting sensors were calibrated using procedures known in the art.[000298] Subsequently, the sensor was placed in a detection environment and connected to suitable measurement systems to acquire the detection signal emitted by the sensor.[000299] Each test was repeated in triplicate to validate the reproducibility of the obtained results.[000300] The detection signals recorded over time are shown in Figure 1 , wherein the abscissa represents time, t [sec], and the ordinate represents the detection signal emitted by the sensor’s sensitive element, TOBJ [counter]. The graph depicts the detection signal as a function of time. The graph is divided into two parts by a vertical line (Y1), representing the moment of introduction of the analyte of interest into the detection environment. To the left of line Y1 , the detection signal prior to analyte binding is shown; to the right, the detection signal after the analyte of interest has been introduced into the measurement system is depicted. A clear shift in the TOBJ detection signal emitted by the sensor is observed, indicating that the input signal to the sensitive element varies upon analyte introduction, and consequently, the detection signal output by the sensitive element changes. Therefore, the detection signal is perturbed by the introduction of the analyte of interest. The detection signal is designated as TOBJ in accordance with existing infrared sensor standards. Irrespective of the unit of measure, a distinct change in the detection signal is observed from the moment of analyte introduction, evidencing sensor perturbation. [000301] Identical trials were performed on a sensor prepared according to EXAMPLE 2, namely with a MIP obtained by pre-functionalizing the coating layer with a brominecontaining compound as the reactive atom. The trials yielded no significant differences compared to those conducted with the sensor of EXAMPLE 1. A clear change in the detection signal upon analyte introduction was observed.[000302] The same trials were also carried out using sensors obtained according toEXAMPLE 3, employing BSA protein as the template molecule and either chlorothiophenol or bromothiophenol. Again, no significant differences were observed compared to the sensors of EXAMPLES 1 or 2. A clear change in the detection signal was observed upon analyte introduction.[000303] It can be concluded that both pre-functionalizing compounds enable the preparation of a molecular sensor capable of binding the template molecule, and that this result is achieved both by polymerizing the polymer directly onto the pre-functionalized coating layer and by applying the molecularly imprinted polymer layer onto the prefunctionalized coating.[000304] The same trials were further performed by immersing the sensors prepared according to EXAMPLES 1 , 2, and 3 into an aqueous environment containing the analyte of interest. In all cases, a variation in the detection signal emitted by the sensor was observed. This demonstrates that the sensor according to the invention can operate in both air and aqueous environments.[000305] This confirms that the sensors of the invention are suitable for use in various measurement environments, whether in water or in air.[000306] Furthermore, this demonstrates that the sensors of the invention can be operated at various humidity levels without requiring special precautions and, importantly, without compromising measurement reliability. The sensor’s response within the tested humidity range is independent of the humidity level present in the measurement environment.[000307] Moreover, it is observed that the sensor according to the invention interacts with the molecularly imprinted polymer and is perturbed by the presence of the desired analyte. [000308] This indicates that the measurements obtained with the sensors of the invention are readily interpretable, at least within the tested humidity range, and that the presence of the analyte of interest is easily detectable.[000309] In all cases, exposure to the analyte significantly perturbs the sensor response, causing a measurable change in the detection signal, irrespective of the prefunctionalization reaction used and / or the MIP growth method.[000310] A sensor prepared according to EXAMPLE 4 was also introduced into the detection environment, and the first and second detection signals, produced respectively by the first and second sensitive elements, were recorded. Upon introducing BSA into the detection environment, a variation in the first detection signal was observed, attributable to the binding of BSA to the molecularly imprinted polymer present on the first filtering device, whereas no substantial variation was detected in the second detection signal emitted bythe second filtering device.[000311] This demonstrates the high selectivity and reactivity of the sensor thus fabricated, further corroborating the results obtained with the sensors of the preceding examples.[000312] The first and second detection signals may be used as-is or processed to derive a differential signal. In this way, a signal independent of possible environmental characteristics, such as temperature or other sources of infrared radiation, can be obtained.

Claims

CLAIMS1. A method for manufacturing a molecular infrared sensor having a molecularly imprinted polymeric detection device for detecting a desired analyte, said method comprising the steps of:- providing an infrared sensor comprising a detection device operatively coupled to an integrated circuit for transmitting a detection signal from said detection device to said integrated circuit, wherein said detection device comprises a sensitive element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by said input signal, said sensitive element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of said sensor, and a filtering device operatively connected to said sensitive element and configured to filter radiation impinging on said sensitive element such that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength between about 5 and about 20 pm;- treating said filtering device so as to pre-functionalize said filtering device by binding at least one functional group thereto, thereby obtaining a prefunctionalized filtering device;- applying onto said pre-functionalized filtering device a molecularly imprinted polymer (MIP), said molecularly imprinted polymer comprising at least one binding site for a desired analyte, thereby obtaining an infrared sensor provided with a molecularly imprinted polymeric detection device suitable for detecting said analyte;- treating said infrared sensor to bond said pre-functionalized filtering device to said molecularly imprinted polymer (MIP).

2. The method according to claim 1 , wherein said applying comprises binding said prefunctionalized polymeric material of said pre-functionalized filtering device to a molecularly imprinted polymer (MIP), said molecularly imprinted polymer comprising at least one binding site for a desired analyte, thereby obtaining an infrared sensor provided with a molecularly imprinted polymeric detection device suitable for detecting said analyte.

3. A method for manufacturing a molecular infrared sensor having a molecularly imprinted polymeric detection device for detecting a desired analyte, said method comprising the steps of:- providing an infrared sensor comprising a detection device operatively coupled to an integrated circuit for transmitting a detection signal from said detection device to said integrated circuit, wherein said detection device comprises a sensitive element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by said input signal, said sensitive element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of said sensor, and a filtering device operatively connected to said sensitive element and configured to filter radiation impinging on said sensitive element such that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength between about 5 and about 20 pm;- treating said infrared sensor so as to pre-functionalize said filtering device by binding at least one functional group thereto, thereby obtaining a prefunctionalized filtering device;- preparing a polymerizable mixture comprising: at least one polymerizable functional monomer; at least one templating compound comprising said analyte; at least one cross-linking agent; at least one polymerization initiator;- contacting said polymerizable mixture with said pre-functionalized filtering device;- polymerizing said polymerizable mixture to obtain a cross-linked polymer containing said analyte bound to said pre-functionalized polymeric material;- removing said analyte from said cross-linked polymer to obtain a molecularly imprinted polymer having at least one binding site for said analyte, thereby obtaining an infrared sensor provided with a molecularly imprinted polymeric detection device suitable for detecting a desired analyte.

4. The method according to any one of the preceding claims, wherein said binding comprises forming chemical bonds, preferably covalent bonds, between said prefunctionalized filtering device and said molecularly imprinted polymer.

5. The method according to any one of the preceding claims, wherein said sensitive element comprises a sensitive element made of a pyroelectric material, preferably selected from the group consisting of gallium nitride (GaN), cesium nitrate (CsNO3), or polyvinyl fluoride.

6. The method according to any one of the preceding claims, wherein said sensitive element comprises a thermally isolated, micromachined transistor fabricated using CMOS-SOI MEMS technology.

7. The method according to any one of the preceding claims, wherein said filtering device comprises a band-pass optical filter configured to transmit towards said sensitive element radiation having a wavelength between about 5 and about 20 micrometers.

8. The method according to any one of the preceding claims, wherein said filtering device is a multilayer filtering device comprising a plurality of superimposed layers.

9. The method according to claim 8, wherein said multilayer filtering device comprises a coating layer applied onto said band-pass optical filter such that said coating layer is positioned upstream of said optical filter along the path towards said sensitive element, said coating layer preferably being made of a material selected from a mineral salt, preferably a metal salt such as zinc sulfide (ZnS), or a metal oxide such as tantalum oxide (Ta2O5), said coating layer preferably being made of crystalline zinc sulfide, and wherein said molecularly imprinted polymer is bound to said coating layer.

10. The method according to claim 8 or 9, wherein said multilayer filtering device comprises a layer made of a silicon-based material arranged as the outermost layer of the filtering device, and wherein said molecularly imprinted polymer is bound to said silicon-based layer.

11. The method according to any one of the preceding claims, wherein said infrared sensor comprises an external casing enclosing said sensitive element.

12. The method according to claim 11 , wherein said filtering device is provided on an external wall of said casing so as to be accessible from outside.

13. The method according to claim 11 or 12, wherein said filtering device comprises an internal filtering device located within said casing and an external filtering device provided on an external wall of said casing, wherein said molecularly imprinted polymer is bound to said external filtering device so as to be accessible from outside and bind the analyte of interest.

14. The method according to claim 13, wherein said external filtering device is made of a silicon-based material.

15. The method according to any one of the preceding claims, wherein said functional group is a halogen, preferably chlorine or bromine, or a vinyl group, and wherein preferably said treating comprises treating said filtering device with a reactive compound so as to bind said functional group to said filtering device, said reactive compound being selected from compounds containing a benzene group (-C6H5) and a halogen atom, said reactive compound preferably being selected from mercaptans, more preferably a halogenated mercaptan, even more preferably selected from compounds having the formula SH-(C6H5)CI or SH-(C6H5)Br.

16. The method according to any one of the preceding claims, wherein said detection device comprises a first sensitive element and a second sensitive element operatively connected to said integrated circuit, said first and second sensitive elements both being adapted to detect infrared radiation emitted by an object located within the field of view of said sensor, said first sensitive element being operatively connected to said filtering device so as to receive an input signal through said filtering device, and said second sensitive element being shielded so as not to be in connection with said filtering device.

17. A molecular infrared sensor for detecting a desired analyte, comprising a detection device operatively coupled to an integrated circuit for transmitting a detection signal from said detection device to said integrated circuit, wherein said detection devicecomprises a sensitive element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by said input signal, said sensitive element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of said sensor, and a filtering device operatively connected to said sensitive element and configured to filter radiation impinging on said sensitive element such that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength between about 5 and about 20 pm, said sensor being produced according to the method of any one of claims 1 to 16.

18. A molecular infrared sensor for detecting a desired analyte, comprising a detection device operatively coupled to an integrated circuit for transmitting a detection signal from said detection device to said integrated circuit, wherein said detection device comprises a sensitive element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by said input signal, said sensitive element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of said sensor, and a filtering device operatively connected to said sensitive element and configured to filter radiation impinging on said sensitive element such that a filtered input signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength between about 5 and about 20 pm, and wherein said detection device comprises a molecularly imprinted polymer having at least one binding site for said desired analyte bound to said filtering device.

19. A method for detecting an analyte in a detection environment, comprising a molecular infrared sensor comprising a detection device operatively coupled to an integrated circuit for transmitting a detection signal from said detection device to said integrated circuit, wherein said detection device comprises a sensitive element configured to receive an input signal and to emit a detection signal in response to a perturbation generated by said input signal, said sensitive element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of said sensor, and a filtering device operatively connected to said sensitive element and configured to filter radiation impinging on said sensitive element such that a filteredinput signal reaches said sensitive element, said filtering device being configured to filter radiation having a wavelength between about 5 and about 20 pm, and wherein said filtering device comprises a molecularly imprinted polymer having at least one binding site for said desired analyte bound to said filtering device, said method comprising the steps of:- positioning said molecular infrared sensor in said detection environment such that said analyte can contact said detection device and bind to said at least one binding site of said molecularly imprinted polymer;- detecting the detection signal emitted by said sensitive element to determine the presence of said analyte in said detection environment.

20. The method according to claim 19, further comprising providing a second infrared sensor alongside said sensor, said infrared sensor comprising a second detection device operatively coupled to a second integrated circuit for transmitting a second detection signal from said second detection device to said second integrated circuit, wherein said second detection device comprises a second sensitive element configured to receive a second input signal and to emit a second detection signal in response to a perturbation generated by said second input signal, said second sensitive element being of the type adapted to detect infrared radiation emitted by an object located within the field of view of said second sensor, and a second filtering device operatively connected to said second sensitive element and configured to filter radiation impinging on said second sensitive element such that a filtered second input signal reaches said second sensitive element, said second filtering device being configured to filter radiation having a wavelength between about 5 and about 20 pm, said method comprising detecting said second detection signal emitted by said second sensor, and preferably comparing said first detection signal and said second detection signal.

21. The method or sensor according to any one of the preceding claims, wherein said analyte comprises a protein, preferably a surface protein of a virus, more preferably a protein of a virus belonging to the Coronaviridae family.

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