Sensor point, sensor cover and sensor with improved excitation light yield
By introducing an aerogel layer into the photochemical sensor film to direct light incident, the problem of light scattering in the prior art is solved, and the effect of improving the fluorescent radiation yield and sensor performance is achieved.
Patent Information
- Application Number
- CN202411736884.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-12-01
- Filing Date
- 2024-11-29
- Publication Date
- 2025-06-03
AI Technical Summary
The existing photochemical sensor films have low light yield on the analyte-sensitive pigment layer due to the scattering of incident light, thereby reducing the yield of fluorescent radiation.
By introducing an aerogel layer into the sensor membrane, the translucent mirror properties are used to direct light incidents, increasing the proportion of light entering the analyte-sensitive pigment layer, thereby increasing the yield of fluorescent radiation.
Increased the proportion of light entering the analyte-sensitive pigment layer, enhanced the yield of fluorescent radiation, improved the performance of the sensor, allowing for reduced amount of luminescent dye used and reduced operating power of the optical sensor.
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Figure CN120084764A_ABST
Abstract
Description
Field of the Invention
[0001] The present invention relates to a sensor spot, a sensor cap comprising the sensor spot, and a sensor comprising the sensor cap, wherein the sensor spot, the sensor cap, and the sensor have an improved excitation of an analyte-sensitive luminescent layer due to improved material properties of the sensor spot. Background Art
[0002] An optical sensor is a sensor based on a photochemical reaction with a measurement medium.
[0003] The measurement principle of a photochemical sensor is based on sending excitation light from a light source (e.g., an LED) of the sensor into a sensor spot contained in a sensor head, wherein the sensor spot is in contact with a medium to be examined containing an analyte to be measured during operation, and its surface faces the medium. The sensor spot contains at least one luminescent dye, which is arranged in an analyte-sensitive pigment layer, wherein the luminescent dye reflects luminescent radiation back to a detection unit of the sensor, and the detection unit converts the measured radiation into an electrical signal and forwards it to sensor electronics.
[0004] Depending on the properties of the luminescent dye, the optical sensor reacts to different analyte concentrations with different light intensities, frequencies, or light attenuation curves.
[0005] The applicant manufactures and sells corresponding sensors in a maximum of different embodiments.
[0006] The sensor unit of the sensor comprises a sensor film or a sensor spot, and the sensor film or the sensor spot includes a substrate, such as a glass plate or an optical fiber, and a polymer / dye mixture customized for a given analyte is applied to the substrate as a solid thin film.
[0007] Generally, such a sensor spot or sensor film is made of multiple layers. An analyte-sensitive pigment layer containing a luminescent dye is applied to a glass substrate made of, for example, quartz glass, and the glass substrate is incorporated into a matrix made of, for example, silicone. A covering layer made of, for example, silicone is applied to the analyte-sensitive pigment layer. A reflective layer (e.g., containing TiO 2 ), which is designed to prevent stray light loss, may be arranged between the analyte-sensitive pigment layer and the covering layer. The reflective layer including silicone and containing TiO 2 has a refractive index significantly different from that of quartz glass and silicone. For example, quartz glass and silicone have a refractive index n of 1.25 to 1.8, while TiO 2 has a refractive index n greater than 2 to 4.
[0008] A disadvantage of the sensor film according to the prior art is the low light yield on the analyte-sensitive pigment layer due to the scattering of the incident light on the film. This results in a lower light yield incident on the analyte-sensitive pigment layer and a low yield of fluorescent radiation. Summary of the Invention
[0009] An object of the present invention is to provide a sensor element or sensor film of a photochemical sensor which overcomes the disadvantages of the prior art by increasing the light yield acting on the analyte-sensitive pigment layer in order to excite the luminescent dyes integrated into the analyte-sensitive pigment layer.
[0010] This object is achieved by providing a sensor spot according to the present invention, a sensor cap comprising the sensor spot according to the present invention, and a sensor comprising the sensor cap according to the present invention.
[0011] The present invention relates to a sensor spot of a photochemical sensor for determining the concentration of an analyte in a measurement medium, comprising
[0012] (i) a film which consists of a plurality of layers, the plurality of layers comprising:
[0013] (ii) an analyte-permeable cover layer (5) which is in contact with the medium during operation and is preferably made of silicone,
[0014] (ii) a reflective layer (4) which is arranged on the side of the cover layer remote from the medium and contains TiO 2 , where, preferably, the TiO 2 layer is applied in a completely covering manner,
[0015] (iii) an analyte-sensitive pigment layer (3) which is arranged on the side of the reflective layer remote from the medium, where the sensor film contains at least one luminescent dye, where the luminescence of the analyte-sensitive layer depends on the concentration of the analyte, and
[0016] (iv) an aerogel layer (6) which is arranged on the side of the analyte-sensitive layer remote from the medium, where the aerogel layer (6) consists of a silicate aerogel, and
[0017] (v) a glass substrate (2) which is arranged on the side of the aerogel layer remote from the medium, where the glass substrate is preferably made of fused quartz.
[0018] In a preferred embodiment, the photochemical sensor spot comprises a silicate aerogel, where the silicate acts as a translucent mirror due to its structure. This allows the light to be directed in a manner directed onto the pigment layer. The silicate aerogel is a material with unusual properties, such as a high specific surface area (500 to 1200 m 2 / g), high porosity (80 to 99.8%), low density (about 0.003 g / cm 3 ), high thermal insulation value (0.005 W / mK), very low dielectric constant (k = 1.0 to 2.0), and low refractive index (about 1.00 to 1.24).
[0019] In a preferred embodiment, the layers of the sensor film are adhesively and / or covalently bonded to each other.
[0020] In a preferred embodiment, the analyte-sensitive luminescent dye is an analyte-sensitive fluorescent or phosphorescent dye, wherein the analyte is
[0021] - a gas dissolved in a medium, the gas being selected from O 2 , CO 2 , O 3 , nitrogen oxides, NH 3 , preferably O 2 ,
[0022] - a cation dissolved in a medium, the cation being selected from hydronium ion, Na + , K + , NH 4 + , Ca 2 + and Mg 2 + , preferably hydronium ion,
[0023] - an anion dissolved in a medium, the anion being selected from chloride ion and nitrate ion, and
[0024] - an organic molecule selected from glucose, lactose, and lactic acid.
[0025] The present invention also relates to a sensor cover of a photochemical sensor for determining and / or monitoring at least one analyte in a medium, comprising a cylindrical inner part containing a sensor spot according to any one of claims 1 to 4, and
[0026] a sleeve-shaped outer part adjacent to the inner part,
[0027] wherein the inner part and the outer part are detachably mechanically connected to each other, preferably via a screw connection.
[0028] The present invention also relates to an optical sensor for determining or monitoring at least one analyte in a medium, the optical sensor having a sensor cover according to the present invention and an electronic component, which are detachably connected to each other, wherein the electronic component is composed of a first module having a light source and a detector and a second module having a transceiver.
[0029] In one embodiment of the optical sensor, the sensor cover is detachably and mechanically connected to the electronic component, preferably via a screw connection.
[0030] In one embodiment of the optical sensor, the first module and the second module are connected to each other via a detachable plug connection unit, wherein the plug connection unit is designed to transmit energy and / or data by means of a current-isolated, in particular inductive, interface, wherein the detachable plug connection unit is preferably a bayonet closure, wherein energy is transmitted unidirectionally from the second module to the first module, and data, in particular data on the analyte concentration, is transmitted bidirectionally between the first module and the second module.
[0031] The invention also relates to an optical analysis system comprising a sensor according to the invention or an embodiment thereof, wherein the second module of the optical sensor is electrically connected to the data processing unit via a connection.
[0032] Aerogel is a porous solid in which up to 99.98% of the volume consists of pores. The aerogel used in the sensor is a silicate aerogel having a refractive index n of 1.00 to 1.24, preferably 1.002 to 1.24.
[0033] The sensor spot is also referred to as the sensor film or the sensor element.
[0034] The sensor spot of the invention improves the proportion of light incident on the analyte-sensitive pigment layer or the luminescent dye layer by repeatedly reflecting the coupling-in radiation between the aerogel layer (which is a semi-transparent mirror) and the reflective layer. Since the proportion of available light with the same coupling-in power increases, the yield of incident light in the sensor spot increases, and thus the yield of fluorescence transmitted to the detector also increases. This improves the performance of the sensor with the same energy input. The improved performance allows for a reduction in the amount of expensive luminescent dye used and / or the optical sensor to operate at a lower power.
[0035] In one embodiment of the optochemical sensor, the light source and the detection unit are directly arranged on the region of the optical component that is remote from the medium during sensor operation. Measuring radiation or light is radiated from the light source onto the sensor spot or the sensor film, or the detection unit receives light from the optical component, wherein there is air between the light source, the detection unit and the sensor spot.
[0036] In an alternative embodiment of the optochemical sensor, at least one optical waveguide is provided by means of which light is guided from the light source to the region of the optical component that is remote from the medium and from the region of the optical component that is remote from the medium to the detector unit during sensor operation.
[0037] In one embodiment, the optical sensor is designed as a hygienic sensor and is used in the fields of bioprocess engineering and / or pharmaceutical process engineering.
[0038] A luminescent material of an analyte-sensitive pigment layer comprising at least one luminescent body is simultaneously sensitive to an analyte such that the light emitted by the luminescent material is affected by the analyte content in the measurement medium, and thereby a biological, chemical or physical measurement quantity can be determined. In this case, the biological, chemical or physical measurement quantity includes, for example, the concentration of the analyte in the medium, such as a gas dissolved in an aqueous medium, such as oxygen concentration, carbon dioxide concentration, nitrogen oxides and / or ozone; the concentration of organic molecules, such as glucose concentration, lactose concentration, lactic acid concentration; the ion concentration, for example by measuring hydronium ions or hydrogen ions and thus pH; the concentration of nitrate ions, chloride ions, ammonium ions, sodium ions or potassium ions, calcium ions or magnesium ions; the concentration of solvents, such as water, or biomolecules - for example luminescent biomolecules, such as antibodies.
[0039] In luminescence, a physical system enters an excited state by externally supplied energy and emits photons when it transitions to the ground state. The term luminescence refers to the process (phenomenon) or the emitted radiation. Fluorescence is defined as the radiation spontaneously emitted during the transition from an electronically excited state to the ground state; if the excited intermediate state can "freeze" the energy for a period of time, this is called phosphorescence.
[0040] The luminescent dye selectively interacts with the analyte to be demonstrated in the measurement fluid such that the optical properties of the luminescent dye change depending on the concentration of the analyte in the measurement fluid in contact with the sensor element.
[0041] In one embodiment, the luminescence intensity, preferably the fluorescence intensity, depends on the concentration of the analyte. For ion-sensitive dyes, preferably pH-sensitive dyes, the luminescence intensity, preferably the fluorescence intensity, depends on the ions in the measurement solution, preferably the concentration of hydrogen ions or hydronium ions.
[0042] In one embodiment, the concentration of the analyte, preferably an ion, more preferably hydrogen ions or hydronium ions, and the pH are determined by dual lifetime referencing.
[0043] Dual time reference measurements involve measuring the luminescence of two different luminescent dyes, where
[0044] the first luminescent dye responds to the analyte in terms of luminescence intensity, and
[0045] the second luminescent dye does not respond to the analyte at least in terms of luminescence intensity and decay time, where
[0046] the first luminescent dye and the second luminescent dye have different decay times, where the decay time of the second luminescent dye is longer than the decay time of the first luminescent dye, where
[0047] The luminescence responses of two phosphors that can be additively superimposed are measured by a single detector in terms of the time or phase behavior, and a reference quantity independent of the total intensity of the two phosphors is obtained from the measured time or phase behavior, and the concentration of the analyte is determined using this reference quantity.
[0048] The first luminescent dye and the second luminescent dye can be arranged in the same layer or in different layers.
[0049] In one embodiment, if an analyte is present, the fluorescence of the fluorophore triggered by the stimulating radiation may decrease (fluorescence quenching principle). In an oxygen sensor, the fluorescent dye is excited by radiation. There is an energy transfer from the excited fluorescent dye (triplet state) to the ground state (triplet state) of oxygen: the decrease in fluorescence intensity depends on the concentration of dissolved oxygen.
[0050] Indicator dyes sensitive to analytes are luminescent dyes from the series of porphyrins, BODIPY, metal porphyrins, benzoporphyrins, azabenzoporphyrins, naphthoporphyrins, phthalocyanines, polycyclic aromatic hydrocarbons, especially perylene, perylenediamine, pyrene; xanthene dyes, azo dyes, bodipy dyes, azabodipy dyes, cyanine dyes, metal ligand complex dyes, especially bipyridines, bipyridyls, phenanthrolines, coumarins, and acetylacetonates of ruthenium and iridium; acridine dyes, oxazine dyes, coumarins, azapentalenes, squaraines, 8-hydroxyquinolines, polymethines, luminescent nanoparticles (such as quantum dots), nanocrystals (which may optionally be covalently bound to a polymer matrix).
[0051] Methods known in the prior art for applying the film layers for producing the sensor spots or sensor membranes include, for example, application by doctor blading, electrospinning, spraying, spray coating, or dip coating.
[0052] As long as technically feasible, all of the above modular systems and measurement systems can be combined with each other. Description of the Drawings
[0053] The present invention is explained in more detail below with reference to the exemplary embodiments shown in the drawings.
[0054] In the drawings:
[0055] Figures 1a to 1b A sensor spot according to the prior art (a) and a sensor spot according to the present invention (b) are shown.
[0056] Figure 2a to Figure 2b Shows the sensor cover in (a) a horizontal arrangement of the sensor element relative to the longitudinal axis of the sensor and (b) an arrangement in which the sensor cover is at an angle to the longitudinal axis of the sensor, where the angle a is between 20° and 40°, preferably 30°.
[0057] Figure 3An optical sensor with an inductive interface is shown. Detailed Description
[0058] Figure 1a Sensor points known in the prior art are shown. Figure 1b Sensor points according to the present invention are shown.
[0059] In the sensor point (1) according to Figure 1a , the sensor layers are applied one on top of the other on a glass carrier (2), wherein the glass carrier (2), preferably made of quartz glass, is arranged on the side remote from the medium during operation of the sensor. An analyte-sensitive pigment layer (3) comprising a luminescent dye is arranged on the medium side of the glass carrier (2). TiO 2 A reflective layer (4) is arranged on the medium side of the analyte-sensitive pigment layer (3). A cover layer (5) is arranged on the medium side of the TiO 2 reflective layer (4), which is permeable to the analyte to be measured but impermeable to the measuring medium (9) (e.g. water) in which the analyte is dissolved. Compared to the coupled-in light (7), the useful light is lost due to scattering effects, resulting in less useful radiation hitting the analyte-sensitive pigment layer (3). Therefore, the proportion of the radiation (8) emitted by the pigment layer (3) is also reduced.
[0060] According to Figure 1b , the sensor point (1) has a structure in which an aerogel layer (6) is arranged between the analyte-sensitive pigment layer (3) and the glass carrier (2). This ensures improved light incidence and thus improved transmittance of the fluorescence radiation (8), wherein the coupled-in light (7) is reflected between the aerogel layer and the reflective layer, and thus the light is used optimally.
[0061] The sensor cover (10) in FIGS. 2a and Figure 2b comprises a sensor point (1) according to the present invention from Figure 1b . The sensor cover consists of an inner part (11) surrounding the sensor point and a shell-shaped outer part (12). The inner part (11) and the outer part (12) are connected to each other via a detachable mechanical connection, wherein the mechanical connection is preferably a screw connection.
[0062] The sensor cover (10) is also connected to the electronic components (15) of the optical sensor via a detachable mechanical connection (21), preferably via a screw connection.
[0063] According to Figure 3The sensor (14) includes a sensor cover (10) and electronic components (14), wherein the electronic module is composed of a first module (16) including a light source (17) and a detector (18) and a second module (19) containing a transceiver (20). The first module (16) and the second module (19) are connected to each other via a mechanical plug connection unit (22), wherein the mechanical plug connection unit (22) includes an inductive interface. Preferably, the mechanical plug connection unit (22) is a bayonet closure.
[0064] The reference signs should not be construed as limiting the scope of the subject matter protected by the claims. They are only used for the purpose of making the claims more understandable.
[0065] Reference signs
[0066] (1) Sensor point or sensor film
[0067] (2) Glass substrate, fused quartz substrate
[0068] (3) Analyte-sensitive layer or analyte-sensitive pigment layer
[0069] (4) TiO 2 Reflective layer
[0070] (5) Cover layer
[0071] (6) Aerogel layer
[0072] (7) Incident light
[0073] (8) Emitted light, fluorescence
[0074] (9) Measuring medium
[0075] (10) Sensor cover
[0076] (11) Internal components of the sensor cover
[0077] (12) External components of the sensor cover
[0078] (13) Mechanical connection, screw connection between the internal and external components of the sensor cover
[0079] (14) Optical sensor
[0080] (15) Electronic components of the sensor
[0081] (16) First module
[0082] (17) Light source
[0083] (18) Light detector
[0084] (19) Second module
[0085] (20) Transceiver
[0086] (21) Mechanical connection, screw connection between sensor cover and electronic component
[0087] (22) Removable plug connection unit
[0088] (23) Electrical connection
[0089] (24) Data processing unit
[0090] (L) Longitudinal axis of sensor cover
[0091] (a) Angle transverse to the longitudinal axis of the sensor cover
Claims
1. A sensor spot (1) of an optical chemical sensor for determining the concentration of an analyte in a measurement medium, comprising: (i) A film, the film being composed of a plurality of layers, the plurality of layers comprising: (ii) an analyte-permeable cover layer (5), which is in contact with the medium during operation and preferably consists of silicone, (ii) a reflective layer (4), which is arranged on the side of the cover layer facing away from the medium and contains TiO2, wherein the TiO2 layer is preferably applied in a completely covering manner, (iii) an analyte-sensitive pigment layer (3) arranged on a side of the reflective layer remote from the medium, wherein the sensor membrane contains at least one luminescent dye, wherein the luminescence of the analyte-sensitive layer depends on the concentration of the analyte, and (iv) an aerogel layer (6), which is arranged on the side of the analyte-sensitive layer facing away from the medium, wherein the aerogel layer (6) consists of a silicate aerogel, and (v) A glass substrate (2) which is arranged on a side of the aerogel layer facing away from the medium, wherein the glass substrate is preferably made of quartz glass.
2. The optical chemical sensor dot (1) according to claim 1, wherein The silicate aerogel (6) has a refractive index of about 1.00 to 1.24, preferably 1.002 to 1.
24.
3. The optical chemical sensor dot (1) according to claim 1 or 2, wherein: The layers of the sensor membrane (1) are adhesively and / or covalently bonded to one another.
4. The optical chemical sensor dot (1) according to any one of claims 1 to 3, wherein: The analyte-sensitive luminescent dye is an analyte-sensitive fluorescent or phosphorescent dye, wherein the analyte is - a gas dissolved in the medium, the gas being selected from O2, CO2, O3, nitrogen oxides, NH3, preferably O2, - cations dissolved in the medium, the cations being selected from hydronium ions, Na + , K + NH4 + , Ca2 + and Mg2 + , preferably a hydronium ion, - anions dissolved in the medium, said anions being selected from chloride and nitrate ions, and - an organic molecule selected from the group consisting of glucose, lactose and lactic acid.
5. A sensor cover (10) for an optical chemical sensor for determining and / or monitoring the presence of at least one analyte in a medium, comprising: A cylindrical inner part (11) comprising a sensor point according to any one of claims 1 to 4, and a sleeve-shaped outer part (12), the sleeve-shaped outer part (12) being adjacent to the inner part, in, The inner part (11) and the outer part (12) are mechanically connected to one another in a detachable manner, preferably via a screw connection (13).
6. An optical sensor (14) for determining or monitoring at least one analyte in a medium, comprising a sensor cover (10) according to claim 5 and an electronic component (15), wherein the sensor cover (10) and the electronic component (15) are detachably connected to each other, wherein: The electronic component is composed of a first module (16) having a light source (17) and a detector (18) and a second module (19) having a transceiver (20).
7. The optical sensor (14) according to claim 6, wherein: The sensor cover is detachably mechanically connected to the electronic component, preferably via a screw connection (17).
8. The optical sensor (14) according to claim 6 or 7, wherein: The first module (16) and the second module (19) are connected to one another via a detachable plug connection unit (22), wherein the plug connection unit (22) is designed to transmit energy and / or data by means of a galvanically isolated, in particular inductive, interface, wherein the detachable plug connection unit is preferably a bayonet closure (22), wherein energy is transmitted unidirectionally from the second module to the first module and data, in particular data about analyte concentrations, are transmitted bidirectionally between the first module and the second module.
9. An optical analysis system comprising the sensor according to any one of claims 6 to 8, wherein: The second module of the optical sensor (14) is electrically connected to a data processing unit (24) via a connection (23).