MXPA97006360A - Optical sensor fluoresce - Google Patents

Abstract

The present invention relates to a fluorescence sensor for sensing an analyte comprising: photodetector means for generating an electrical signal as a result of being exposed to incident light; indicator means for providing a fluorescent emission as a result of excitation light, said indicator means comprising a material that allows said analyte to propagate therein and having specific light emitting indicator molecules for said analyte to cause said indicator molecules to interact with said analyte to alter the amount of light incident on said light photodetector medium emitted from said indicator molecules, light emitting means for emitting excitation light having at least a portion located within said indicator means, said photodetector means having a primary axis of light detection and said light emitting means having a primary axis of light emission, said photodetector means and said medium or light being located to cause the primary axis of light emission of said light emitting means to be substantially perpendicular to the primary axis of light detection of said photodetector means, said photodetector means, said indicator means and said light emitting means being located in a unitary structure

Description

OPTICAL FLUORESCENT SENSOR BACKGROUND OF THE INVENTION Fluorescence is a photochemical phenomenon in which a photon of specific wavelength of light (excitation wavelength) hits an indicator molecule, thus exciting an electron to a higher energy state as a result of the collision. As that "excited" electron decomposes back to its original base state, another photon of light is released at a longer wavelength (emission wavelength). The indicator molecules are specific in their wavelengths of excitation and emission. Fluorescent emission from an indicator molecule can be attenuated or enhanced by the local presence of the molecule being analyzed. For example, a molecule of tr? S (4,7-diflume-1, 10-phenatrol-1-phenanthroline) specific for the perception of oxygen is excited by illuminating the substance at 460nrn (blue). Fluorescent emission of molecules occurs immediately at 620 nm (orange-red). However, the emission is extinguished by the presence of oxygen that interacts with the indicator molecule, to cause the intensity of the fluorescence to be related to the concentration of oxygen in the environment. Therefore, the more oxygen is present, the lower the emission intensity and vice versa and when no oxygen is present, the fluorescent intensity ax l of emitted is present. F analytical techniques using fluorescent molecules as indicators have been used mainly in fluorescence spectrophotometers. These instruments are designed to measure the fluorescence intensity and also the time of fluorescence decomposition. These devices typically cost 20,000 to 50,000 dollars and are usually used in research laboratories. A second area of the state of the art of fluorescence sensor is in the fiber optic device. These sensor devices allow the minimization and remote sensing of specific analysts. The fluorescent indicator molecule is immobilized by mechanical means or by chemistry at one end of an optical fiber, at the opposite end of the fiber a fiber coupler (Y-shaped fiber) or beam splitter is fixed. The incident excitation light is coupled at one end of the fiber typically by a filter and a lens. The excitation light is carried by the fiber to the far end where the fluorescent indicator molecule is immobilized to the tip. During the excitation, the indicating molecule emits uniformly fluorescent light, part of which is recovered by the tip of the fiber and propagated back through the fiber to the Y junction or "coupler". At the junction, a substantial portion (typically half) of the fluorescence is transported back to the emitter or point of origin thus unavailable for signal detection. In order to divert inefficiencies from the system, lasers are often used to raise input power and highly sensitive photornulting tubes are used as detectors, thus raising costs to thousands of dollars. The other half travels along the other extremity of the Y to the detector and registers. A major disadvantage with the system is the losses that occur in each fiber union and by the slow and filters. The system is at a maximum of 1-5% efficiency with loss resulting in sensitivity and scale. These devices have been shown in the laboratory and are available commercially and very recently for several limited applications. These devices differ from the eep > Fluorescence electrophotometers previously mentioned as being dedicated to their specific application. In view of the foregoing, it is clear that there are precise limitations associated with such fluorescence devices as the prior art including cost mea- sures and limitations related to use. further, said fluorescence devices of the prior art are complex with many separate parts and are bulky. This invention overcomes these problems associated with the above fluorescence devices and provides a fluorescence device with greatly reduced costs and complexity as well as improved efficiency. This invention provides a novel platform that greatly extends the use of fluorescent indicator molecules or a sensor that allows analysis of utilization, sensitivity and cost that were not previously available. The invention has also increased the usages and is easier to use as well as it is more reliable than the fluorescence devices of the prior art.

BRIEF DESCRIPTION OF THE INVENTION This invention relates to fluorescence devices and more particularly to fluorescence sensors. Accordingly, an object of the invention is to provide an improved fluorescence sensor. An object of the invention is to provide a fluorescence sensor that is highly efficient. An object of the invention is to provide a fluorescence sensor with improved optical efficiency. An object of the invention is to provide a fluorescence sensor having improved sensitivity. An object of the invention is to provide a fluorescence sensor having few parts. An object of the invention is to provide a fluorescence sensor that is easy to manufacture. An object of the invention is to provide a fluorescence sensor that has greatly reduced manufacturing costs. An object of the invention is to provide a fluorescence sensor that is manufactured with standard manufacturing techniques. An object of the invention is to provide a fluorescence sensor that is easy to assemble. An object of the invention is to provide a fluorescence sensor that is low in cost. LC) It is an object of the invention to provide a fluorescence sensor having an increased number of uses. An object of the invention is to provide a fluorescence sensor that can be used in harsh environments. An object of the invention is to provide a fluorescence sensor having increased thermal tolerances. An object of the invention is to provide a fluorescence sensor that is miniature. An object of the invention is to provide a fluorescence sensor with reduced volume. An object of the invention is to provide a fluorescence sensor that provides increased functionality at reduced volume. An object of the invention is to provide a fluorescence sensor with increased functional density. An object of the invention is to provide a fluorescence sensor that is well suited for use in places where the available volume is limited. It is an object of the invention to provide a fluorescence sensor that is well suited for use in a variety of different fields, it is an object of the invention to provide a fluorescence sensor that includes a transmitter element that is embedded within the scope of the invention. a chemically active element. An object of the invention is to provide a fluorescence sensor that includes an emitter element that is embedded within a polymer (organic or inorganic) within which the reporter molecule is immobilized. An object of the invention is to provide a fluorescence sensor that can be used as a platform p > fluorescent, luminescent, phosphorescent, absorbent or refractive difference indicator molecules immobilized in or within the polymer where the emitter is embedded. An object of the invention is to provide a fluorescence sensor with an embedded emitter wherein the technique of investigating the indicator molecule is by means of direct excitation / emission, evanescent excitation, or excitation of the surface plasmon resonance type or indirect excitation by a secondary fluorescent molecule. An object of the invention is to provide a fluorescence sensor in which the emission element that is embedded is integral with high and low pass optical filters.

An object of the invention is to provide a fluorescence sensor having an integral optical detection element or diode. It is an object of the invention to provide a fluorescence sensor that is constructed in a one-piece unit is constructed in a one-piece unit substantially in a single-piece or integral package. An object of the invention is to provide a fluorescence sensor where all optical processing is Lf) contained within the integral component and only the energy and signal conduits enter and exit the device or unit act LVO. An object of the invention is to provide a fluorescence sensor where the enclosed emitter is a die-emitting diode 15 (DEL) pair thus providing optimal radial emission of excitation radiation from the source. An object of the invention is to provide a fluorescence sensor in which the primary axis of excitation radiation from a light emitting diode is perpendicular to the primary e e of the photodetection of the photodetector emission. An object of the invention is to provide a fluorescence sensor that eliminates the need for optical fibers. An object of the invention is to provide a fluorescence sensor with a unitary structure in which all the radiation of the light source is released at the beginning and propagated through the indicator layer, either inside the layer or immobilized to the surface of the layer. An object of the invention is to provide a fluorescence sensor that can be used in the analysis of gaseous and liquid states. An object of the invention is to provide a fluorescence sensor that can be used integral with its signal processing electronics or as a remote device. An object of the invention is to provide a fluorescence sensor wherein the thickness of the membrane or indicator layer is controlled by pouring the contents formulated by gravity or pressure around the emitter die. It is an object of the invention to provide a fluorescence sensor wherein the thickness of the indicator layer is optionally limited only by the thickness of the radiation emitting P / N junction. An object of the invention is to provide ur >; Fluorescence sensor that has a low pass filter that is a coating or film. An object of the invention is to provide a fluorescence sensor having a high pass filter which is a coating, film or platelet. An object of the invention is to provide a fluorescence sensor that can be used for a multitude of anayites by immobilizing a specific reporter molecule in or within the sensor indicator layer and calibrating the signal processing electronics. An object of the invention is to provide a fluorescence sensor * whose electronic signal processing can include phase modulation, life, methods of interpreting data of intensity or relative intensity. An object of the invention is to provide a fluorescence sensor that can have any omission wavelength and any detection wavelength. An object of the invention is to provide a fluorescence sensor in which the low and high pass filters can be of any suitable exclusion / admission profile for the chosen indicator molecules. An object of the invention is to provide a fluorescence sensor wherein the sensor is a solid state sensor. An object of the invention is to provide a fluorescence sensor that is designed for extremes of temperature, pressure and ambient conditions. These and other objects will be apparent from the invention of the fluorescence sensor having a photodetector, a high-pass filter located adjacent to the photodetector, and a glass layer adjacent to the high-pass filter. Also, an indicator layer is located adjacent to the glass layer and a light emitting diode is embedded in the indicator layer. The indicator layer has indicator molecules that provide a fluorescent emission as a result of light to n from the light-emitting diode. The indicator layer allows an analyte to propagate in it and the presence of the analyte is the amount of light emitted from the indicator molecules that pass to tr-birds from the glass layer and the high-pass filter and is incident in the photodetector. Since the amount of current from the photodetector depends on the incident light, this is used to detect the presence and quantity of the analyte. In one embodiment, a waveguide is also present.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described below in detail with reference to the accompanying drawings in which: Figure 1 is a partially exploded view in perspective of the invention of the fluorescence sensor illustrating its component parts and the manner in which it is manufactured; Figure 2 is a top plan view of the invention of the fluorescence sensor set forth in Figure 1; Figure 3 is an elongated sectional view of the invention of the fluorescence sensor set forth in Figures 1 and 2 taken substantially on line 3-3 of Figure 2; Figure 4 shows a top view of a second embodiment of the invention of the fluorescence sensor; Figure 5 is an elongated sectional view of the invention of the fluorescence sensor set forth in Figure 4 turned substantially on line 5-5 of Figure 4; and Figure ñ is a perspective view of the embodiments of the invention of the fluorescence sensor in use as a mdicator.

DETAILED DESCRIPTION OF THE PREFERRED MODE Referring to Figures 1, 2 and 3, the invention of the fluorescence sensor is illustrated and is designated generally by the number 10. The sensor 10 comprises light detecting means for detecting light comprising a photodetector or platelet 12 substantially flat. thin, filtering means for filtering light comprising a substantially thin planar high-pass filter layer 14 having a generally circular perimeter which is located adjacent to and optically coupled to the photodetector means comprising the photodetector plate 12 and a substantially thin flat glass plate 16 having a generally circular perimeter which is located adjacent to and optically coupled to the filter medium comprising the high pass filter layer 14. The sensor 10 also comprises a indicating means for providing an emission fluorescent as a result of excitation light comprising a layer of thin indicator membrane substantially plane 18 having a generally circular perimeter which is located adjacent to and coupled to the glass layer 16, light emitting medium for emitting excitation light comprising a light emitting diode 20 (DEL) which is located in the central portion of the indicator layer 18 and an electrically conductive refractive metallic disk 22 which is located between the light emitting diode 20 and the glass plate 16 plus the filter medium for filtering light which a pass filter filter coating 24 surrounding the upper portion of the light emitting diode 20. As indicated in Figure 1, the indicator layer 18 is poured into place. The details of the construction of the sensor can be better understood by referring to Figure 3 as well as Figure 1. As illustrated in Figures 1 and 3, the layer of the photodetector 12 is connected to a positive post 26 and a negative post. 28 whose respective upper end portions 30 and 32 are electrically connected to the layer of the photodetector 12. A wire 36 has one end welded or secured by conductive adhesive to the upper end portion 30 of the post 26 and the other end is fixed or secured in a manner conventionally to the upper surface 38 of the layer of the photodetector 12. Similarly, a wire 40 has one end secured to the upper end portion 32 of the post 28 by welding or by conductive adhesive and the other end is secured or fixed to the side lower 34 of the photodetector 12 in a conventional manner.

The high-pass filter layer 14 has its lower side 42 secured to the upper side or surface 38 of the photodetector-12 layer by a very thin layer of optical adhesive 44 and the upper surface 46 of the high-pass filter layer 14. is secured to the bottom surface 48 of the glass layer 16 by another very thin layer of optical adhesive 50. The reflective metal sheet 22 is fixed to the upper surface 52 of the glass layer 16 by a suitable adhesive 53 known in the art. and the light emitting diode 20 is fixed to the upper surface of the reflector metal foil 22 by a layer of electrically conductive adhesive 54. The low pass filter coating 24 is secured to the upper outer portion of the foil. light-emitting diode 20 by light-conducting adhesive 36. The electric wires 58 and 60 are provided for the light-emitting diode 20 and extend respectively from the light-emitting diode 20 and the metallic sheet disk electrically connected 22 to the respective upper end portions 66 and 68 of the posts 62 and 64 whose respective upper end portions 66 and 68 are located below the outer portion of the lower surface 42 of the filter layer 1. The indicator membrane layer 18 contains indicator molecules designated by number 71 and is molded on the upper surface 52 of the glass layer 16 as well as around the light emitting diode 20 and its low pass filter screen 24 and portions thereof. its wires 58 and 60.

Also, there is provided a machined circular metal ring-shaped housing 70 that surrounds the outer edges of the layer of the photodetector 12, the filter layer 14, the glass layer 16 and the membrane layer 18. The lower portion of the mechanical housing 70 is enclosed or sealed with molding cermet or other molding material 72 known in the art which also secure posts 26, 28, 62 and 64 in place. Accordingly, the sensor 10 is a unitary structure with all its operating components located within the housing 70 and only the positive and negative signal poles 26 and 28 and the electrical power poles 62 and 64 that extend from the structure unit surrounded by and contained within the housing 70. It is important to note, as indicated in FIG. 3, that the light emitting diode 20 and the photodetector 12 are located in such a way that the primary or main axis of light emission from the light emitting diode 20, designated by the letter fl, is substantially perpendicular to the primary axis or princip > al, designated by the letter B, of light detection of the photodetector 12. This is very important for the fluorescence sensor 10 since it results in high efficiency and high sensitivity. Another embodiment of the invention of the fluorescence sensor is set forth in FIGS. 4 and 5 and is generally designated by the number 74. The sensor 74 comprises a photodetector means for detecting light comprising a layer of the thin photodetector 76 which is substantially identical to the plate or layer of the photodetector described above 12, filtering means for filtering Light comprising a high pass filter layer 78 which is substantially identical to the high pass filter layer 14 described previously and a glass layer 80 which is Substantially identical to the glass layer 16 previously described, the high-pass filter layer 78 is located adjacent to and optically coupled to the photodetector means comprising the layer or plate 76 of the photodetector. The glass layer 80 is located adjacent to and optically coupled to the filter medium comprising the filter layer 78. However, the sensor 74 also has waveguide means for operating as a waveguide comprising a guide layer substantially thin flat wave 82 whose lower surface 84 is located adjacent to and in optical contact with the upper surface 86 of the glass layer 80 as a result of the optical adhesive 88. The upper surface 90 of the waveguide layer 82 is located adjacent to and in optical contact with the lower surface 92 of an indicator layer 94. This indicator membrane layer 94 has indicator molecules designated by the number 95 and can be molded on the upper surface 90 of the waveguide layer 82. The sensor 74 also has light emitting medium that emits excitation light comprising a light-emitting diode 96 that is similar to diode 20 previously describedfilter medium for filtering light comprising a low pass filter coating 98 surrounding the IB portions of the diode 96 which is similar to the low-pass filter liner 24 described previously and the light-emitting diode 96 has its lower surface in contact with a thin electrically conductive metal reflector foil disc 100 which is similar to the foil disc reflector 22 previously described. As illustrated in Figure 5, the sensor 74 has respective positive and negative posts 102 and 104, which are similar to the posts 26 and 28 described previously, and are electrically connected to the respective upper side 105 and bottom side 106 of the layer. of the photodetector 76 in a conventional manner by the respective electrical wires 107 and 109. The high-pass filter layer 78 has its lower surface 114 secured to the upper surface 112 of the photodetector layer 76 by a very thin layer of similar optical adhesive 116 to the adhesive 44 previously described. The upper surface 118 of the high-end filter 78 is also secured to the lower surface 120 of the glass layer 80 by a thin layer 122 of optical adhesive similar to the adhesive 50 previously described. The reflective metal sheet disk 100 is connected to the upper surface 86 of the glass layer 80 by a suitable adhesive known in the art and the light emitting diode 96 is fixed to the upper surface of the reflective metal sheet 100 by a layer of electrical conductive adhesive 124 and the low pass filter layer 98 is secured to the diode 96 by a light conducting adhesive coating (not shown). The light-emitting diode 96 has associated electrical wires 128 and 130 that respectively extend from the diode 96 and the metal sheet 100 located below and in electrical contact with the diode 96 to the respective poles 13? and 134 which are located below the external lower side 114 of the high-pass filter layer 78 in a manner similar to that for the wires 58 and 60 and the respective posts 62 and 64 of the embodiment set forth in Figures 1 to 3. it will be noted that the light-emitting diode 96 and its underside or low-pass filter layer 98 is surrounded by the waveguide layer 82 that is molded around the light-emitting diode 96 and its low-pass filter coating. which are centrally located on the p > The central orb of the glass layer 78. Also provided is a machined metal housing in the shape of a circular ring 139, which is substantially identical to the metal housing 70 of the embodiment 10, which surrounds the outer edges of the layer of the metal layer. photodetector 74, the filter layer 78, the glass layer 80, the wave guide layer 82 and the indicator layer 94. The lower portion of the machined housing 70 is closed or sealed with molding ware or other known molding material 141 in the art which is identical to the material 72 of the embodiment 10. This material 141 also secures the posts 102, 104, 132 and 134 in place. Accordingly, the sensor 74 is a unitary structure, the same as the mode of the sensor 10, with all its operating components located within the housing 139 and only the positive and negative signal poles 102 and 104 and the electrical power poles 132. and 134 extending from the unitary structure surrounded by and contained within the housing 139. It is important to note, as indicated in Figure 5, that the light emitting diode 96 and the photodetector 76 are located in such a way that the primary axis or principal of light emission from the light-emitting diode 96, designated by the letter 0, this substantial entity perpendicular to the primary or main axis, designated by the letter I), of the light detection of the photodetector-75. it is very important for the fluorescence sensor 74 since it gives as a result high efficiency and high sensitivity. As illustrated in Figure 6, the positive post 26 of the sensor 10 is electrically connected to the positive input 140 of a light intensity indicator 142 by the driver 144., the switch 146 and the conductor 148. Similarly, the negative post 28 is electrically connected to the negative input 150 of the light intensity indicator 142 by the conductor 152, the switch 154 and the conductor 156. Alternatively, the sensor 74 it can be electrically connected to the light intensity indicator 142 having the positive pole 102 of the sensor 74 connected to the positive input 140 of the light intensity indicator 142 by the conductor 158, the switch 146 and the conductor 148. Similarly, the pole negative 104 is connected to the negative input 150 of the light intensity indicator 104 by the conductor 150, the i-switch 154 and the conductor 156. As a result of this arrangement, the intensity output of the sensor light 10 or 74 it can be read on the meter 162 of the light intensity indicator 142 through the use of switches 146 and 154. In the preferred embodiments of both fluorescence sensor modes 10 and 74 are manufactured using standard components and techniques known in the art in the following manner. With respect to the mode of the fluorescence sensor 10, the external housing of a normal optical diode detector such as a UDT020 available from United Detector Technoloy of Hawthorne, California, is removed to expose the surface of the silicon photodiode 12. On the surface upper 38 of the diode 12 is placed a small drop of optical adhesive 44 as manufactured by Norland Products of New Brunswick, New Jersey or another similar adhesive. A high-pass thin-film color filter 14 is cut from a normal sheet on a circular disk and placed on the surface 38 of the diode 12 thus covering the active diode area with the specific wavelength filter that is fixed to the surface 38 of diode 12 by optical adhesive 44. A p &g filterThe suitable particle 14 can be selected and obtained from any photographic light supply such as R to R Lightmng Company, Inc. of Silver Spring, Naryland. A second small drop of optical adhesive 50 (NorLand type) is placed on the upper surface 46 of the optical film filter disc 14. On this surface a circular glass disk 16 of a diameter exceeding that of the color filter 14 and the dimensions of the detector photodiode 12 is placed. The glass disk 16 is fixed to the upper surface of the color filter disk 14 by the optical adhesive 50. On the upper surface 52 of the glass disk 16 is placed a small drop 53 of high temperature epoxy, such as that produced by Epoxy Technology, Billercia, Tassachusetts, approximately at the center of disc 16 (the placement, but the center is preferred). An electrically conductive metal disc 22 of much smaller diameter (approximately 300 microns) is fixed to the glass by the high temperature epoxy 53 and a wire 60 (or ink line or adhesive conductor) is then placed on the glass layer surface 52 between the metal disk 22 and a pin or conductor post 64 which is fixed below or adjacent to the photodetector which is a photodiode 12 which allows e electrical conduction between the post 64 and the metallic disc 22 located in the center. A small drop of electrically conductive adhesive 54 is placed on the upper surface of the metal disk 22 such as that made by Circuit Urs, Inc. of Santa Cruz, California, and others. In the conductive adhesive 54 and the associated metal disc 22 is placed a DEL 20 emitter die such as that made by Cree Research, Durham, North Carolina and others, thus forming an electrical path between the post 64 as previously described and the cathode (or alternatively anode) of the DEL die 20. On the upper surface (anode or cathode) of the DEL die 20 one end of a second fine wire electric wire 58 is joined and the wire 58 is directed through the two posts 62 and 64 thus activating the die of DEL 20 to emit light through the surface of and in radial proximity to the upper surface of the glass disk 16. This stacked and adhered arrangement comprising the photodetector 12, the filter 14, the The glass layer 16, the metal disc 22 and the photodetector 20 and the high-pass filter liner 24 are then glued inside a circular housing 70 machined to a dimension that covers and protects the sides of the disposition ei. The p-ep fair of the 16 glass disc with epoxy (Epoxy Technology), thus sealing the front face and those components under the glass disc 16 of the environment. In a cavity created by the upper surface 52 of the glass disc 16 and the side wall machined in the housing 70 is poured a membrane indicator formulation 18 (Figure 1) covering the surface 52 of the glass layer 16, embedding the die of DEL 20 and its wires 58 and 60 and can fill at a level equal to the thickness machined in the housing 70. The DEL 20 is submerged a minimum. Due to the formation of the membrane indicator mixture 18, the liquid is leveled across the surface and polymerized and cured, thus immobilizing the indicator molecules 71 and forming an active porous membrane or the outer surface on the sensor face. 10. The thickness of the membrane can be controlled by precise volumetric dispensing on the surface 52 of the glass layer 16. The membrane / indicator formulation can be changed to create different sensors specific for different analytes. In an example embodiment, the membrane is formulated and applied in the following manner to create a specific sensor for oxygen. Starting with 1 rnl of silicon (commercially available co or Dow Corning, Midland, Michigan, RTV Sealant) diluted with 2 ml of Naptha (EE Zirnmerrnan Cornpany, Pittsburgh, Pennsyl ania) and swirl in a sealed glass test tube (volume of 13+ ce). Add 200 ul of 6 mg / ml of ruthenium complex of fluorescent indicator molecule dissolved in chloroform. Swirl homogeneously and pipette 250 ul of this solution onto the surface of the glass as described in the previous device. Let-cure 'at room temperature overnight or in reduced time at higher temperatures (not exceeding 60 ° C). The lower cavity below the bottom side 34 of the photodetector 12 that is formed by the housing 70 is then filled with the molding material 72 which seals the housing 70 and also secures the different positions., 28, 62 and 64 instead. This example is ready to be used as an oxygen sensor when coupled with suitable electronics. Other examples differ from the above description only by changing the type of indicator molecule 71 and membrane formulation 18. As indicated in Figure 5, modality 74 uses a waveguide layer 82 but is constructed identically as mode 10. except that a non-porous waveguide layer 82 is poured onto the surface 86 of the glass layer 80 instead of a porous membrane of the 10th mode. There is no reporter molecule within the waveguide layer 0.00. indicator molecules 95 are immobilized in an indicator layer 94 located on the upper surface-90 of the layer LC) 80. As an example of the embodiment 74, a clear polymer (organic or inorganic) is poured onto the surface 86 of the glass layer 80 and is to be leveled and cured. The polymer waveguide is chosen for adequate clarity and refractive index properties so as to optimally display light of the desired wavelength through its volume. The indicator molecule layer 94 is attached to the upper surface 86 of the waveguide layer 82 with the indicial molecules "Hores indicated by No. 95 which are immobilized to the upper surface or surface 86 of the waveguide layer. 82 using any dozen common techniques known in the art, thus completing the construction of the device. The specificity of the sensor 10 or 74 for a particular analyte conferred by the choice of immobilized indicator molecule 71 or 95. Then, the optical properties of the waveguide 82 are chosen to accommodate their optimal wavelengths.

The modes of the sensor 10 and 74 of this invention are used in the following manner. The LO and 74 sensors can be used in many different applications and environments. The sensor specificity of the sensor confers by the indicator molecule 71 or 95 chosen from many commercially available (SIGMA and others) and as listed in the scientific literature. For example, sensor 10 or 74 can read oxygen using many different molecules as listed in the scientific literature and are available commercially and are known to those skilled in the art. As an oxygen sensor, the device can be used to analyze the concentration of dissolved oxygen in a liquid or suspension, ie water, chemicals, process streams, fermentation broths, waste treatment streams, etc., or to analyze the concentration of oxygen in a gas mixture such as air, various gas mixtures containing oxygen used in combustion, environmental conditions in spaces or closed reactors or life support systems. In one example of many, the sensors 10 and / or 74 previously described are connected to the electronics comprising a signal amplifier (not shown) of the detector photodiode which can form part of the measuring means for measuring the electrical signal of the photodetector medium such as the light intensity indicator 142 and a power supply (not shown) p > to activate the DEL 20 or 96. As the sensor 10 or 74 is placed in the environment to be analyzed, oxygen is dispersed in the indicator layer "Je membrane 18 or 94 where the oxygen interacts with the indicator molecules 71 or 95 at a molecular level that causes a reduction in fluorescence intensity as detected or observed by the photodetector 12 or 76, thus reducing the electronic signal to the processing electronics that form the measuring means 142 to measure the current electrical from the photodetector means 12 or 76 which is calibrated to read oxygen in suitable units of measurement known in the art. Even < } Since the invention has been described in considerable detail with reference to certain preferred embodiments, it will be appreciated and understood that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (9)

NOVELTY OF THE INVENTION CLAIMS

1. - A fluorescence sensor for analyzing an analyte comprising: photodetector means for generating an electrical signal as a result of being exposed to incident light; indicator means for providing a fluorescent emission as a result of lu / 'of excitation, said indicating means- comprising a material that allows said analyte to propagate therein and having specific light emitting indicator molecules for said analyte to cause said analyte Indicator molecules interact with said analyte to alter * the amount of light incident on said photodetector medium of the light emitted from said indicator molecules; light emitting means for emitting excitation light having at least a portion located within said indicating means; said photodetector means having a primary axis for detecting light and said light emitting means having a primary light emitting ee, said photodetector means and said light emitting means being located so as to cause the primary ee of light emission of said light emitting means is substantially perpendicular to the primary axis of light detection of said photodetector means; said photodetector means, said indicator means and said light emitting means being located in a unitary structure.

2. - The fluorescence sensor according to claim 1, further characterized in that it comprises a medium of Liter to filter light located between said indicator means and said photodetector means.

3. The fluorescence sensor according to claim 2, further characterized in that said fLitro means filters light above and below a certain length of ond.

4. The sensor * «fluorescence according to claim 3, further characterized in that said filter means comprises a high pass filter.

5. The fluorescence sensor according to claim 3, further characterized in that it comprises a second filter means for filtering light surrounding a portion of said light emitting means.

6. The fluorescence sensor according to claim 1, further characterized in that said light emitting means comprises a light emitting diode.

7. The fluorescence sensor according to claim 1, further characterized in that said photodetector means has an electrical signal output and comprises a measuring means connected to said photodetector means- to measure the output of electrical signal "said said photodetector means -.

8. The fluorescence signal according to claim 1, further characterized by comprising a housing that surrounds at least a portion of said photodetector means, said indicator means and said light emitting means.

9. The fluorescence sensor * according to claim 1, further characterized in that it comprises a glass layer located adjacent said indicator means *. LO.- The fluorescence sensor according to claim 1, further characterized in that said "n" l collector comprises a signaling membrane substantially flat. 11. The fluorescence sensor according to claim 1, further characterized in that the light emitting indicator molecules of said indicator medium interact with oxy ene. 12. A fluorescence sensor for sensing an analyte comprising: photodetector means for generating an electrical signal as a result of being exposed to incident light; indicator means for providing fluorescent emission as a result of excitation light, said indicator means comprising a material that allows said analyte to propagate therein and having specific light emitting indicator molecules for said analyte to cause said indicator molecules interact with said analyte to alter the amount of light incident on said photodetector medium of the light emitted from said indicator molecules; a waveguide layer located adjacent said indicator means; light emitting means for emitting excitation light having at least a portion surrounded by said waveguide layer; said photodetector means having a primary light detecting axis and said emitter means of uz having a primary axis of light emission, said photodetector means and said light emitting means being located to cause the primary emission eye of light of said light emitting means is substantially perpendicular to the primary axis of light detection of said photodetector means; said photodetector means, said indicator means, said waveguide layer and said light emitting node being located in a unitary structure, 13.- The fluorescence sensor according to claim 12, further characterized in that it comprises filter medium. to filter light located between said waveguide layer and said photodetector means. 14. Fl fluorescence sensor according to claim 13, further characterized in that said filter means comprises a high pass filter. 15. The fluorescence sensor according to claim 13, further characterized in that it comprises a second filter means for filtering light surrounding a portion of said light emitting means. 16. The fluorescence sensor according to claim 12, further characterized in that said light emitting means comprises a light emitting diode. 17.- The fluorescence sensor "In accordance with claim 12, caraeteriza" Jo in addition because said means' IO The photodetector has an electrical signal output and comprises measuring means connected to a medium photodetector for measuring the electrical signal output of said photodetector means. 18. The fluorescence sensor according to claim 12, further characterized in that it comprises a housing that surrounds at least a portion of said photodetector means, said indicator means and said guide layer of on a. 19. The luorescence sensor according to claim 12, further characterized in that it comprises a glass layer located adjacent to said waveguide layer.