Sensing system for specific substance and molecule detection

Abstract

A system for detecting a specific substance or analyte of interest is provided that includes one or more sensing units and an instrument for analyzing the sensing units. Each sensing unit preferably includes a substrate, an attachment layer and at least one capture layer that includes a ligand layer. In one embodiment, the attachment layer is tripartite and includes a lower binding surface held to the substrate and an upper binding surface that holds the ligand layer, together with an insulating layer disposed between these two surfaces. The lower binding surface provides a durable and stable attachment to the substrate. The upper binding surface holds the ligand layer and does not jeopardize the integrity or viability thereof. The insulating layer prevents any unwanted interaction between the lower and upper binding surfaces. Each sensing unit is supported on a test piece received by the instrument. The instrument controllably positions the test piece using marks and/or codes on the test piece. The instrument measures a difference in mass in the sensing unit in connection with determining whether or not the analyte of interest is present. A light beam is used in making this measurement. In one embodiment, multiple reflections of the light beam on the same sensing unit are utilized to improve the sensitivity of the instrument. Mass enhancement techniques are also preferably utilized to effectively amplify the detected signal that is indicative of the analyte's presence. The system can also include a device for heating, humidifying and mixing materials of the sensing units, as well as preventing cross-contamination of the sensing units.

What is claimed is:  
     
         1 . A sensing unit involved in detecting an analyte of interest, comprising: 
 a substrate having an outer surface;    an attachment layer for adhering to said substrate, said attachment layer used for controlled binding of at least a first material and in which said substrate outer surface has properties that cause unwanted effects on the first material, said attachment layer including: 
 a lower binding surface having a material composition that adheres to said substrate in order to provide a durable and stable lamination of said attachment layer to said substrate;  
 an upper binding surface having a material composition different from said material composition of said lower binding surface, said upper binding surface including binding properties associated with said first material which requires a controlled immobilization environment to retain its functional characteristics; and  
 an insulating layer disposed between said lower binding surface and said upper binding surface, said insulating layer having a material composition different from each of said material compositions of said lower binding surface and said upper binding surface and in which said insulating layer acts to prevent the transfer of unwanted effects from said lower binding surface to said upper binding surface and from said upper binding surface to said lower binding surface;  
   wherein each of said material compositions of said lower binding surface and said upper binding surface has properties that are enhanced by the use of said insulating layer.    
     
     
         2 . A sensing unit, as claimed in    claim 1   , further including: 
 at least one capture layer joined to said attachment layer for providing an environment in which the analyte of interest, when present, is properly immobilized to permit its subsequent detection, said capture layer including said first material.    
     
     
         3 . A sensing unit, as claimed in    claim 1   , wherein: 
 each of said material compositions of said lower binding surface and said upper binding prevent it from being used for said material composition of said insulating layer.    
     
     
         4 . A sensing unit, as claimed in    claim 1   , wherein: 
 said substrate is other than a free electron metal.    
     
     
         5 . A sensing unit, as claimed in    claim 1   , wherein: 
 one of said lower binding surface and said upper binding surface consists essentially of inorganic monovalent compounds having linear backbone structures.    
     
     
         6 . A sensing unit, as claimed in    claim 1   , wherein: 
 one of said lower binding surface and said upper binding surface consists essentially of at least one of organic monovalent and polyvalent compounds and in which said compounds have particles that retain their particle size of at least 40 microns or do not have said particles.    
     
     
         7 . A sensing unit, as claimed in    claim 1   , wherein: 
 said lower binding surface consists essentially of an organofunctional silial compound.    
     
     
         8 . A sensing unit, as claimed in    claim 1   , wherein: 
 said attachment layer includes some of the following materials: 6-azidosulfonylhexytriethoxy silane, aminoethyl-aminopropyl trimethoxy silane, aminopropyltrioxysilane, 3-isocyanatopropyltriethoxysilane, phenyltriethoxysilane, poly(ethylene)glycol, poly(ethylene)oxide, nitrocellulose, paralene, nylon, polyester, polyamides, polyurethane, polystyrene, avidin (and its derivatives), and biotin.    
     
     
         9 . A sensing unit, as claimed in    claim 1   , wherein: 
 said insulating layer consists essentially of one or more materials from the following group: polystyrene, polyurethane, and polyethylene glycol.    
     
     
         10 . A sensing unit, as claimed in    claim 7   , wherein: 
 said organofunctional silial compound includes amino-silane, azido-silane and silanes comparable thereto.    
     
     
         11 . A sensing unit, as claimed in    claim 1   , wherein: 
 said substrate consists essentially of a crystalline silicon.    
     
     
         12 . A sensing unit, as claimed in    claim 1   , wherein: 
 said first material i s a specific material.    
     
     
         13 . A sensing unit, as claimed in    claim 1   , further including: 
 mass enhancement means for amplifying a signal for detection related to the presence of the analyte of interest.    
     
     
         14 . A sensing unit, as claimed in    claim 12   , wherein: 
 said mass enhancement means includes one or more enzymes associated with such attachment layer.    
     
     
         15 . A sensing unit involved in detecting an analyte of interest, comprising: 
 a substrate other than a free electron metal and having an outer surface;    an attachment layer for adhering to said substrate, said attachment layer used for controlled binding of at least a first specific material and in which said substrate outer surface has properties that cause unwanted effects on the first specific material, said attachment layer including: 
 a lower element having a material that adheres to said substrate in order to provide a durable and stable lamination of said attachment layer to said substrate, said lower element consisting essentially of an organofunctional silial compound; and  
 an upper element having a material composition different from said material composition of said lower element, said upper element including an outer surface including binding properties associated with said first specific material which requires a controlled immobilization environment to retain its functional characteristics;  
   at least one capture layer joined to said attachment layer for providing an environment in which the analyte of interest, when present, is properly immobilized to permit its subsequent detection, said capture layer including said first specific material;    wherein said material composition of said upper element has properties that prevent it from being used for said material composition of said lower element.    
     
     
         16 . A biosensor device, as claimed in    claim 15   , wherein: 
 said organofunctional silial compound includes amino-silane, azido-silane and silanes comparable thereto.    
     
     
         17 . A sensing unit, as claimed in    claim 15   , wherein: 
 said upper element consists essentially of one or more of the following: polystyrene, polyurethane and polyethylene glycol.    
     
     
         18 . A sensing unit, as claimed in    claim 15   , further including: 
 mass enhancement means associated with said attachment layer for amplifying detection of the analyte of interest.    
     
     
         19 . A sensing unit, as claimed in    claim 18   , wherein: 
 said mass enhancement means includes one or more enzymes provided with said upper element.    
     
     
         20 . A sensing system for obtaining information related to sensing units, comprising: 
 a test piece having a number of sensing units and indicating means associated with each of the sensing units;    a housing having a number of walls and a receiver slot for receiving said test piece wherein said test piece can move along a path of said housing;    a light beam assembly for obtaining information from each sensing unit for use in determining the presence of a specific substance of interest; and    controller means located within said housing for causing said test piece to move relative to said housing path.    
     
     
         21 . A system, as claimed in    claim 20   , wherein: 
 said indicating means includes indicia and said controller means includes a reader assembly for reading said indicia in connection with stopping movement of said test piece along said housing path.    
     
     
         22 . A system, as claimed in    claim 21   , wherein: 
 said indicia includes an identification code that identifies at least one of the sensing units.    
     
     
         23 . A system, as claimed in    claim 20   , wherein: 
 said controller means comprises a test piece control assembly that includes a motor disposed within said walls of said housing.    
     
     
         24 . A system, as claimed in    claim 20   , further including: 
 an input unit provided on one of said walls of said housing for inputting information related to the sensing units.    
     
     
         25 . A system, as claimed in    claim 20   , further including: 
 display means located on one of said walls of said housing for displaying information associated with the sensing units.    
     
     
         26 . A system, as claimed in    claim 20   , further including: 
 data memory for storing data related to each of the sensing units including identification data, time-related data and data related to whether or not the analyte of interest is present.    
     
     
         27 . A system, as claimed in    claim 20   , further including: 
 at least a first port communicating with an external computer system by which said external computer system can download software for execution by a processor of said controller means.    
     
     
         28 . A system, as claimed in    claim 20   , wherein: 
 said controller means includes a processor for determining values related to the sensing units and whether or not an analyte of interest is present for each of the sensing units.    
     
     
         29 . A system, as claimed in    claim 20   , wherein: 
 said indicating means includes at least one of a mark to indicate a location of each of the sensing units and a code for identifying at least one of the sensing units.    
     
     
         30 . A system, as claimed in    claim 20   , wherein: 
 said controller means includes a number of electronic components including a processor and in which said electronic components are held on a printed circuit board and in which said printed circuit board is located between said light beam assembly and an input unit for providing input information used by said processor.    
     
     
         31 . A system, as claimed in    claim 20   , wherein: 
 said light beam assembly includes polarizer means for receiving polarized light having only one component when each sensing unit is tested to determine whether the sensing unit has the analyte of interest and in which said polarizer means remains stationary when said polarized light is being received.    
     
     
         32 . A system, as claimed in    claim 20   , wherein: 
 said light beam assembly generates a number of reflected light beams having intensities for each of the sensing units, with each of said reflected light beams being produced at an angle different from perpendicular to each of the sensing units.    
     
     
         33 . A system, as claimed in    claim 32   , wherein: 
 said light beam assembly includes a curved mirror that reflects and transmits light and wave retarder means for providing additive polarization of said reflected light intensities for each of the sensing units to enhance sensitivity for determining the presence of the analyte of interest.    
     
     
         34 . A method for obtaining assay data, comprising: 
 providing a test piece having a number of sensing units;    controlling movement of said test piece;    checking for identifying means on said test piece;    discontinuing movement of said test piece based on said checking step;    obtaining data related to a first sensing unit on said test piece including determining whether an analyte of interest is present using an optical detecting apparatus; and    storing information related to said determining step including identification data related to the first sensing unit, time-related data, and a determined value related to whether the analyte of interest is present with the first sensing unit.    
     
     
         35 . A method, as claimed in    claim 34   , wherein: 
 said controlling step includes regulating a motor using a processor that receives a signal based on said identifying means.    
     
     
         36 . A method, as claimed in    claim 34   , wherein: 
 said identifying means includes at least one of a first code that identifies a first sensing unit and alignment indicia that indicates a position of at least one of the sensing units.    
     
     
         37 . A method, as claimed in    claim 34   , wherein: 
 said providing step includes inserting said test piece into a receiver slot of a housing that contains said optical detecting apparatus and, before said inserting step, locating said indicating means on said test piece.    
     
     
         38 . A method, as claimed in    claim 34   , wherein: 
 said controlling step includes regulating the turning on and turning off of a motor using a processor and contacting said test piece using means for engaging driven by said motor in order to move said test piece.    
     
     
         39 . A method, as claimed in    claim 34   , further including: 
 inputting identification information related to at least one of the sensing units using an input unit provided on one of the walls of a housing that contains said optical detecting apparatus.    
     
     
         40 . A method, as claimed in    claim 34   , wherein: 
 said obtaining step includes obtaining data for all of the sensing units on said test piece and maintaining an angular position of polarizer means of said optical detecting apparatus during receiving of light intensities for all of the sensing units on said test piece, with said light intensities being used to provide said data for all of the sensing units.    
     
     
         41 . A method, as claimed in    claim 34   , wherein: 
 said obtaining step includes collecting at least portions of light related to a number of reflected light beams having intensities that are reflected from areas of the first sensing unit and in which each incident light beam from which each of said reflected light beams are generated is at an angle other than perpendicular to the first sensing unit.    
     
     
         42 . A device for heating and providing humidity to a number of sensing units contained on a test piece, comprising: 
 a heating assembly for heating sensing units when a test piece containing them is provided with said device;    a humidifier assembly communicating moisture to said heating assembly for humidifying the sensing units;    a barrier manifold for substantially preventing cross-contamination of the sensing units when the test piece containing them is provided with said device; and    a mixing assembly for mixing of materials in the sensing units when the test piece containing them is provided with said device.    
     
     
         43 . A device, as claimed in    claim 42   , wherein: 
 said heating assembly includes a plate sub-assembly that is heated for providing heat by conduction to the test piece when it is provided with said device.    
     
     
         44 . A device, as claimed in    claim 42   , wherein: 
 said heating assembly includes a support frame that is joined to said plate sub-assembly with both of said support frame and said plate sub-assembly being pivotal.    
     
     
         45 . A device, as claimed in    claim 42   , wherein: 
 said humidifying assembly includes water holding means located below said heating means.    
     
     
         46 . A device, as claimed in    claim 45   , wherein: 
 said water holding means includes at least a first sponge member positioned to a side of said heating assembly and at least one well for containing water adjacent to said first sponge member.    
     
     
         47 . A device, as claimed in    claim 42   , wherein: 
 said barrier manifold includes a number of spaced barrier members that act to separate each of the sensing units from the other sensing units when the test piece containing the sensing units is positioned in said device.    
     
     
         48 . A device, as claimed in    claim 42   , wherein: 
 said barrier manifold is pivotal and applies a pressure to the test piece when the test piece is positioned in said device.    
     
     
         49 . A device, as claimed in    claim 42   , wherein: 
 said mixing assembly includes a motor that is positioned at an angle to enhance the mixing of the materials in the sensing units.    
     
     
         50 . A device, as claimed in    claim 49   , wherein: 
 said angle is greater than about 10 degrees but less than about 70 degrees.    
     
     
         51 . An instrument for detecting an analyte of interest, comprising: 
 first means for supporting a sensing unit to be tested;    second means for locating the sensing unit in a desired position; and    third means for determining whether the analyte of interest is present with the sensing unit being tested, said third means including an optical detecting apparatus for generating a number of light reflections from the sensing unit, with each of said light reflections being at an angle other than 0°, 90° and Brewster's angle relative to said first means, said third means including collection means for collecting at least portions of said light reflections and using said collected light reflections in determining whether the analyte of interest is present.    
     
     
         52 . An instrument, as claimed in    claim 51   , wherein: 
 said means for generating includes a mirror and a wave retarder plate, said wave retarder plate being disposed in a path of said light reflections between the sensing unit and said mirror and wherein said wave retarder plate causes said light reflections that pass through it to be additive of polarization change.    
     
     
         53 . An instrument, as claimed in    claim 52   , wherein: 
 said mirror includes curved portions and in which said mirror has optical power and a reflective coating, with portions of said light reflections received by said mirror being transmitted through said mirror.    
     
     
         54 . An instrument, as claimed in    claim 52   , wherein: 
 said mirror has a reflective coating and said wave retarder plate is a portion of said reflective coating.    
     
     
         55 . An instrument for detecting an analyte of interest, comprising: 
 first means for supporting a sensing unit to be tested;    second means for locating the sensing unit in a desired position; and    third means for determining whether the analyte of interest is present with the sensing unit, said third means including an optical detecting apparatus that has means for generating polarized light having only one component and means for extinguishing said one component, wherein said means for generating and said means for extinguishing remain fixed in position during the time that said optical detecting apparatus provides light to the sensing unit.    
     
     
         56 . An instrument, as claimed in    claim 55   , wherein: 
 said one component includes one of s-polarization and p-polarization.    
     
     
         57 . An instrument, as claimed in    claim 55   , wherein: 
 said means for generating includes a linear polarizer that receives light prior to said light being incident upon the sensing unit and said means for extinguishing includes a detector polarizer that receives light reflected from the sensing unit.