Abstract:
The invention provides for a multiple analyte detector that is capable of detecting and identifying explosive, chemical or biological substances having multiple analytes with a single system having multiple reporters. The reporters include fluorescent polymers, conducting polymers, metal oxide elements electrochemical cells, etc. The reporters may be combinations of other reporters that are optimized for broadband detection.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not Applicable. 
     STATEMENT AS TO FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     BACKGROUND 
     Currently available gas-based detectors for explosives, hazardous chemicals, dangerous biological substances, or chemical/biological warfare substances have limited ability to detect multiple threats. For example, a single-target detector may be limited to one type of a particular reporter designed to respond to an analyte for a specific substance, such as a particular explosive or chemical. These detectors commonly have a short and limited operational period prior to replacement or servicing. Because a gas, such as an air sample, can carry more than one analyte from an explosive, a hazardous chemical, or a dangerous biological substance, multiple detectors are required for every use. 
     Government agencies involved in the inspection of transitory goods and/or people are usually responsible for the detection of explosives, hazardous chemicals or dangerous biological substances, or other contraband. These government agencies are looking for potentially masked or hidden dangerous substances that present a danger to the public. Using several different detectors with different reporters imposes a large logistical footprint and considerable consumable expense upon the governmental agencies. In practice, budgetary constraints force the governmental agency to purchase one or two detectors, each having a single reporter. Even if the governmental agency has several different detectors with different reporters, they may use only one detector to speed up the processing time of the transitory goods or people. The deployment of one type of detector over another means the agency is guessing as to which dangerous substance or other contraband they may encounter. 
     Unfortunately, anyone who observes the governmental agencies, or knows how the government typically operates, is able to ascertain the governmental agencies&#39; practices and actions. This increases the threat from those intentionally creating these dangerous substances for nefarious reasons. The same dangerous situation occurs with those who ignorantly ship dangerous or hazardous substances. In both instances, limited deployment of multiple types of detectors increases the threat to harm to people and property. 
     Non-governmental agencies (NGA) also require systems capable of detecting and monitoring hazardous chemicals and biological substances quickly enough to prevent an accident. Similar to the government agency approach, the larger number of detectors required by the NGA increases the logistical footprint and associated expenses. When the NGA employs a single detector, they decide the most probable hazardous chemical or biological substance they will encounter. Unfortunately, chemicals and biological substances can change their properties when they are mixed, or when they contact other substances. To protect against the range of different types hazards requires several different types of detectors. 
     Of the known detectors, most use a porous membrane coated with a chemical or reporter. The selected reporters will respond to analytes carried by a gas. A sample interacts with the reporter, creating a specific response, such as fluorescing or undergoing a color change. The detection occurs as the sample flows through the porous membrane. 
     A detector and system is needed that can detect more than one explosive, chemical, biological substance and/or a combination thereof. Additionally, such a system needs to be lightweight, easily deployed, and reduce the consumable expenses by reducing the number of consumable elements. The easily portable multi-analyte detection system needs to minimize the impact of untargeted contaminates, as well as, decreasing the complexity for the end user, and decreasing the intervals between trade-outs of the consumable. Rapid detection of these substances saves lives and property. 
     SUMMARY 
     In one embodiment, the current invention provides an apparatus for detecting an analyte substance in a gas sample. The apparatus comprises a flow system carrying a sensor head and a heating block. The sensor head and the heating block define a module receiver therebetween. The apparatus has a gas inlet positioned on the sensor head and provides gaseous fluid communication to a sample area. The apparatus has a gas outlet positioned on the sensor head, and provides gaseous fluid communication from the sample area. The apparatus has a sealing edge positioned on the bottom of the sensor head and within the module receiver. The apparatus also has a heater positioned within the module receiver and positioned to provide heat to the sensor head, the heating block, and the module receiver. A module carrying a substrate is positioned within the module receiver, wherein the module carries a window. The substrate carries at least one reporter thereon. The reporter is selected for its ability to respond to a particular analyte carried by the gas sample. The substrate is exposed to the gas sample in the window of the module. The bottom of the sensor head, the sealing edge, and the substrate defines the sample area. The sealing edge and the substrate define a leak-free seal therebetween. The sample area is positioned within the window. The apparatus has at least one optical port in optical communication with the sample area. The optical port provides optical communication for at least one optical illuminator suitable for illuminating the sample area, and for at least one optical detector suitable for detecting a change in fluorescence, color, or a chemiluminescent reaction. The apparatus has a control system that is in electronic communication with the optical illuminator, the optical detector, and the module. 
     In another embodiment, a method for detecting multiple analytes is disclosed. The method comprises:
         a. capturing a gaseous sample with a detector, said detector carrying a sample port for receiving said gaseous sample and an exhaust port for expelling said gaseous sample;   b. communicating said gaseous sample to a plurality of reporters, said reporters positioned upon a substrate carried by a removable module positioned within said detector;   c. creating a response between an analyte and at least one said reporter, said analyte carried by said gaseous sample;   d. detecting said response with a detector, said detecting step identifying said analyte;   e. notifying a control device regarding the identity of said analyte; and   f. communicating said reporting step to a display, said communicating being controlled by said control device.       

     In still another embodiment, the current invention provides an apparatus for detecting an analyte substance in a gas sample. The apparatus comprises a detector, a module and a control system. The detector has a flow system and the flow system carries a sensor head and a heating block. The sensor head and the heating block define a module receiver therebetween. The sensor head has a sealing edge positioned thereon. The detector also has a gas inlet positioned on the sensor head, and provides gaseous fluid communication to a sample area. The detector has a gas outlet positioned on the sensor head and provides gaseous fluid communication from the sample area. The detector has a heater positioned within the module receiver and positioned to provide heat thereto. The detector has at least one optical port in optical communication with the sample area, wherein the optical port provides communication from an optical illuminator and an optical detector. The module houses a substrate, wherein the substrate carries a plurality of reporters thereon. The control system provides control of the detector, optical illuminator, optical detector, and module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic perspective view of prior art reporter vessels. 
         FIGS. 1B and 1C  are end-views of the prior art reporter vessels of  FIG. 1A  showing the vessel with and without the reporter. 
         FIG. 2  is a schematic perspective view of a cartridge-based system of the current invention. 
         FIGS. 3A and 3B  are schematic plan views of multiple reporter substrates. 
         FIG. 4  is a schematic perspective view of a flow system for the detection apparatus. 
         FIG. 5  is a schematic bottom view of a flow system. 
         FIGS. 6-9  are schematic perspective views of different modules containing the substrate. 
         FIG. 10  is a schematic perspective view of a flow system with a cartridge. 
         FIG. 11  is a schematic perspective view of a self-contained detection apparatus. 
         FIG. 12A  is a schematic perspective view of a spring-biased lever arm self-contained detection apparatus. 
         FIG. 12B  is a schematic perspective view of a spring loaded slide self-contained detection apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 2-12B , the detection apparatus is illustrated and generally designated by the numeral  10 . Detection apparatus  10  includes flow system  12 , module  14 , substrate  16  within module  14 , detection system  18  and detector/processor system  20 . Flow system  12  is capable of receiving module  14 . Module  14  defines a storage and transport system for substrate  16 . Module  14  can be in any shape, as discussed herein, and shown in  FIGS. 2 and 6-9 . For illustration purposes, module  14  is shown herein and generally referred to herein as cartridge  22 . Cartridge  22  contains substrate  16  and exposes a portion of substrate  16  through window  72  to a gas flowing through flow system  12 .  FIG. 1  depicts rigid, fragile modules of the prior art. 
     Detection Apparatus 
     In the preferred embodiment of  FIGS. 10 and 11 , detection apparatus  10  is positioned within housing  24 . Detection apparatus  10  is also referred to as detector  10 .  FIGS. 12A and 12B , discussed below, are two alternative configurations of detection apparatus  10 . To provide fluid communication between the external environment and flow system  12 , housing  24  carries sample port  26  and exhaust port  28 . 
     In a preferred embodiment, detection system  10  includes a plurality of fiber optic cables  30  connected to detection ports  32  of flow system  12 . Fiber optic cables  30  provide optical communication with detection system  18 . Preferably, housing  24  incorporates detection system  18  therein, as depicted in  FIG. 11 . Alternatively (not shown), housing  24  detachably connects to detection system  18 . 
     Preferably, detection apparatus  10  includes power source  34 , which provides power to all systems. Power source  34  is any convenient source of power, or sources of power, that provides sufficient power to the remainder of detection apparatus. Preferably, power source  34  includes a selectable plurality of sources of power. 
     Detection apparatus  10  also includes control system  36 , which includes at least one processor, memory device, data entry port and communications port. Control system  36  provides the control of detection apparatus  10 , which includes positioning substrate  16  within flow system  12 , and detecting and processing the response when the analytes respond to reporters  38  as the gas sample passes over reporters  38 . Commonly used reporters  38  are defined below. Preferably, control system  36  provides the processing capability to operate detection system  18  and the associated discrimination of the detected analyte. Control system  36  and detection system  18  are in electronic communication. Control system  36  preferably stores all electronic data and displays the pertinent information for an operator to take any necessary actions. The electronic storage device is preferably co-located with control system  36 . 
     Regarding  FIG. 12A , a different embodiment of detection apparatus  10  is shown where cartridge  22  is retained on housing  24  by spring-biased lever arm  52 . Spring  56  provides the bias to spring-biased lever arm  52 . In this embodiment, sensor head  39  is located within housing  24 . In response to spring  56 , sealing block  62  exerts pressure on cartridge  22 , and provides for the sealing of substrate  16 , cartridge  22  and sensor head  39 . 
     Regarding  FIG. 12B , another embodiment of detection apparatus  10  is shown where cartridge  22  is retained on housing  24  by spring-loaded slide  64 . Similar to the embodiment shown in  FIG. 12A , sensor head  39  is located in housing  24 . Using a bias spring (not shown), spring-loaded slide  64  applies pressure to sealing block  62 , which then exerts pressure on cartridge  22 , and provides for the sealing of substrate  16 , cartridge  22  and sensor head  39 . 
     Flow System 
     Referring to  FIGS. 4, 5, 10 and 11 , housing  24  contains flow system  12  therein. Flow system  12  includes sensor head  39 , gas sample inlet  40 , gas sample outlet  42 , heating block  43 , at least one heater  46 , bossed rim  48 , and sample area  50 . Heating block  43  and heater  46  cover an area at least as wide as substrate  16 , and in some cases an area greater than that of substrate  16 . The configuration of sensor head  39  and heating block  43  defines a module receiver  44 . The defined module receiver  44  is configured to receive a module  14 . Preferably, module  14  is selected prior to the design of flow system  12 . As shown in  FIGS. 10 and 11 , module receiver  44  has a configuration suitable for permitting the insertion of window  72  of cartridge  22  between sensor head  39  and heating block  43  of flow system  12 . In one embodiment, module receiver  44  operates to close around and seal module  14 .  FIGS. 12A and 12B  depict two examples of this embodiment. However, those skilled in the art know the different types of closing and sealing mechanisms that will function with module receiver  44  as it closes about module  14 , or cartridge  22 . Window  72  provides access for the gas sample to interact with reporters  38  carried by substrate  16 . Window  72  exposes the portion of substrate  16  and reporters  38  to flow system  12 . Window  72  is open both above and below substrate  16 , 
     Gas sample inlet  40  provides gaseous fluid communication between sample port  26  and sample area  50 . The bottom of sensor head  39 , bossed rim  48 , and substrate  16  define sample area  50 . Bossed rim  48  provides a leak-free seal on substrate  16  for sample area  50 . Sealing edge  49  includes bossed rim  48 , as well as other known surfaces that provide a seal between the bottom of sensor head  39  and substrate  16 . Thus, bossed rim  48  is a subset of sealing edge  49 . Sample area  50  is positioned within window  72 . Sample area  50  exposes reporters  38  on substrate  16  to a sample of gas communicated from sample port  26  across sample area  50 . Gas sample outlet  42  communicates the gas sample from sample area  50  to exhaust port  28 . 
     Pump  54 , in gaseous fluid communication with exhaust port  28 , creates a pressure drop between sample port  26  and exhaust port  28 , thereby inducing flow across sample area  50 . Although the preferred embodiment positions pump  54  internal to housing  24 , the embodiment shown in  FIG. 11  positions pump  54  externally. This demonstrates that pump  54  may be positioned anywhere between sample area  50  and exhaust port  28 . Preferably, pump  54  creates a pressure drop sufficient to create a flow rate of about 1.0 liters/minute or less across sample area  50 . In one embodiment, pump  54  selectively creates either a constant flow rate of at least 1.0 liters/minute or less, or a variable flow rate less than about 1.0 liters/minute. In another embodiment, pump  54  has only a constant flow of at least 1.0 liters/minute or less. 
     Heater block  43  carries at least one heater  46 . Preferably, heater  46  provides thermal input sufficient to increase the temperature of flow system  12  and substrate  16 . By applying heat to flow system  12 , the gas sample is more likely to convey the analytes from the external environment to sample area  50  and reporter  38 . For example, a gas sample may contain trace amounts of an explosive matter. At room temperature, the trace amounts of explosive matter begin to adhere to the surface of intake  66 . By heating flow system  12 , the gas sample is less likely to adhere. Thus, the warmer flow system  12  keeps the trace amounts of explosive matter in a gaseous state and suspended within the gas sample. Preferably, heater  46  maintains heating flow system  12  at an operating temperature between about 40° C. and about 200° C.  FIG. 4  depicts a non-limiting example of a placement of heater  46 . Heater  46  may be placed anywhere on flow system  12  that provides sufficient heating. When heated, substrate  16  is also heated by heater  46 , or alternatively, substrate  16  is heated by a separate source (not shown). 
     Module/Cartridge 
     As previously indicated, cartridge  22  is used throughout to represent module  14 . However, cartridge  22  represents only one possible, non-limiting configuration of module  14 . The skilled artisan understands that module  14  may be in any shape capable of holding and conveying substrate  16  to sample area  50 .  FIGS. 6-9  depict four examples of module  14 .  FIG. 6  depicts cartridge  22  as module  14 .  FIG. 7  depicts a variation of a cartridge as module  14  having a single storage reel that feeds substrate  16  through window  72  and sample area  50  into catch bin  68 .  FIG. 8  depicts a disk-type version of module  14  for transporting substrate  16  through window  72  and sample area  50 .  FIG. 9  depicts a strip-like version of module  14  for providing transport of substrate  16  through window  72  and sample area  50 . Any form of module  14  will work. However, in one embodiment, module  14  has a sealed storage capacity for substrate  16  and it provides for the movement of substrate  16  through window  72  and sample area  50 . In another embodiment, module  14  has an unsealed storage capacity for substrate  16  and it provides for the movement of substrate  16  through window  72  and sample area  50 . 
     To preclude false positives, contamination, and loss of reporter  38  material, module  14  includes seal  71  or other configuration that precludes premature exposure of substrate  16  to the environment. In one embodiment, unexposed substrate  16  is sealed within module  14  from premature exposure for any of the aforementioned module  14  examples. In one alternative embodiment using cartridge  22 , end  70  of cartridge  22  is isolated by seal  71  at window  72  thereby precluding exposure of reporters  38  on substrate  16  housed within end  70 . In this embodiment, seal  71  flexes sufficiently to permit advancement of substrate  16  to window  72  for exposure within sample area  50  without loss of reporter from substrate  16 . Preferably, seal  71 , when used, is a material that does not respond to any of the potential reporters  38  or substrate  16 . Seal  71  may be made from a variety of materials such as felt, rubber, paper, silicone, neoprene, other non-responsive materials, and combinations thereof. 
     Continuing with the illustration of module  14  with cartridge  22 , cartridge  22  has window  72  exposing substrate  16  to sample area  50 . Preferably, the size of window  72  allows bossed rim  48  of module receiver  44  to fully contact substrate  16 , such that the activation of pump  54  creates a vacuum sealing substrate  16  to bossed rim  48 . Thus, bossed rim  48  or sealing edge  49 , in cooperation with the top of substrate  16  and the bottom of sensor head  39 , defines sample area  50 . Thus, activation of pump  54  will pull the sample gas in through gas sample inlet  40  passing the sample over reporters  38  carried by substrate  16 , and subsequently directing the gas sample out through gas sample outlet  42 . 
     Cartridge  22  automatically advances substrate  16  through sample area  50  after a pre-determined period, or after a detection event. This automatic advancement optimizes the exposure of reporter  38 . The advancing mechanism for cartridge  22  may be of any type known to those skilled in the relevant art. Some non-limiting examples include manual advance devices, electric or pneumatic motors, solenoids, pistons, or other electro-mechanical or electro-pneumatic device. Control of the associated advancement of cartridge  22  is accomplished using control system  36 . Substrate  16  is advanced from the edge of the exposed area until an entirely new, unexposed area of substrate  16  is within window  72 . For the non-sealed embodiment of cartridge  22 , substrate  16  advances and reporter  38  remains unaffected. For the sealed embodiment of cartridge  22 , a sealing element (not shown) allows substrate  16  and reporter  38  to advance without damaging reporter  38 . In one embodiment, substrate  16  may carry a removable protective layer (not shown) to protect reporter(s)  38  in cartridge  22 . The removable protective layer is automatically removed as substrate  16  advances into window  72 . 
     Preferably, identification of cartridge  22  to control system  36  occurs during installation. A barcode, a radio frequency identification (RFID) chip, manually entered descriptive identifier, or any other identifier provides the unique identifier for cartridge  22  as it is installed. The unique identifier allows control system  36  to identify cartridge  22  and obtain data concerning reporters  38  supplied with the installed cartridge  22 . The unique identifier associated with cartridge  22  facilitates the control, operation and distribution of cartridge  22 . 
     Once cartridge  22  has been identified, control system  36  optimizes the exposure of substrate  16  based upon the indicated reporters  38 , and the number of exposures, illuminations, and durations thereof. Automation and control for advancing of cartridges  22  is well known to those skilled in the art of cartridge making, and not detailed herein. 
     Substrate 
     Substrate  16  is a nonporous medium suitable for carrying a variety of reporters  38 . As a non-limiting example,  FIG. 3A  shows a preferred substrate  16  having reporter(s)  38 , optional calibration strip  74 , and/or optional preconditioning strips  76  positioned thereon. Preferably, reporter(s)  38  are adhered to substrate  16  and/or disposed on a definable segment of substrate  16  in tracks  78 .  FIG. 3A  depicts an example of a substrate  16  carrying a plurality of reporters  38  and optional preconditioning strips  76 .  FIG. 3A  also depicts using segment  58  of substrate  16  as calibration strips  74 .  FIG. 3B  depicts an alternative embodiment of substrate  16  with reporter(s)  38  in sequential order in block segments  60 . 
     Unlike the glass-based prior art examples of  FIG. 1 , when used in cartridge  22 , substrate  16  is preferably a flexible material which retains its integrity up to a temperature of about 200° C. Alternatively, substrate  16  in module  14  is a rigid plate or disk as shown in  FIG. 8 . Substrate  16  may be opaque, translucent or transparent as long as it is consistent with the placement of optical illuminator(s)  84  and detection system  18  relative to substrate  16 . Substrate  16  preferably is electrically non-conductive, but has sufficient thermal conductivity to allow heating of reporters  38 . 
     Particularly preferred substrate  16  material will not respond to reporters  38 . For example, substrate  16  may be a plastic selected from the group consisting of polyethylene terephthalate (PET), Polyethylene Terephthalate Glycol (PETG), polyethylene naphthalate, cyclo-olefin copolymer, polycarbonate, polyimide, cellulose acetate, cellulose triacetate, acrylics, styrenes, and combinations thereof Additionally, the aforementioned plastics may be hard coated. As known to those skilled in the art, these compounds may be processed and formulated to provide the flexibility necessary for use in cartridge  22 . 
     Preferably, substrate  16  must be able to perform the function of a gasket for the bossed rim  48 . To ensure adequate flow through sample area  50 , substrate  16  may not be porous nor allow any flow of the gas sample therethrough. Substrate  16  must be able to seal against bossed rim  48  when pump  54  creates a pressure drop across sample area  50 . The seal between substrate  16  and bossed rim  48  prevents unwanted leakage into sample area  50  or contamination of the gas sample. However, substrate  16  must have sufficient roughness to allow reporters  38  to adhere thereto. Optionally, a non-reactive, non-responsive o-ring (not shown) assists in the sealing of bossed rim  48  to substrate  16 . Alternatively, a combination of a rigid surface, a rimmed surface, a compliant surface, or an o-ring assists in the sealing of bossed rim  48  to substrate  16 . 
     Optional calibration strip  74  provides a known reporter-type response to detection system  18  during initial insertion of cartridge  22  into flow system  12 . For example, if reporter  38  is a fluorescing type of reporter, optional calibration strip  74  will provide a known response for checking the operation of the components of detection apparatus  10 . Optional calibration strip  74  provides a signal to detection apparatus  10  to verify strength of the signal and quality of the signal. 
     Optional preconditioning strips  76  positioned on substrate  16  upstream of the gas sample flow provide a binding agent to capture contaminates. Preferably, optional preconditioning strips  76  capture contaminates. Optional preconditioning strips  76  are preferably positioned on block segment  60  of cartridge  22  near gas sample inlet  40 . 
     Detection System 
     The response between an analyte in the gas sample and reporter  38  may produce a fluorescent response, may produce a change in the fluorescence, a change in color, or a change in the chemiluminescence. Detection system  18  detects responses to an analyte exposed to the portion of substrate  16  carrying reporter  38 . The response optically transmits from sample area  50  to detector/processor system  20 . Detector/processor system  20  provides analysis and positive identification of an analyte of the gas sample. Detector/processor system  20  communicates the analysis and identification of the analyte to control system  36 . Control system  36  provides for the tracking of gas sample history and visual identification. However, those skilled in the relevant art understand that detector/processor system  20  is capable of providing these same functions. 
     Preferably, detection system  18  shown in  FIG. 4 , detects the response of the analyte in module receiver  44  at optical port  80  and/or optical port  82 . In the preferred embodiment, optical ports  80  and  82  are utilized. As shown in  FIGS. 5 and 10 , optical ports  80  and  82  are below substrate  16 . Optical ports  80  and  82  may be positioned above, below or anywhere in an optical line of sight, or can be optically conducted to substrate  16 , as long as optical illuminator  84  and optical detector  86  are able to optically communicate with substrate  16  and reporter  38  within sample area  50  while a response is occurring between the gas sample and reporter  38 . 
     Detection system  18  has at least one optical illuminator  84  and at least one optical detector  86 . Optical illuminator  84  and optical detector  86  are positioned to be in direct or indirect optical communication with either optical port  80  or optical port  82 . Preferably, optical illuminator  84  and optical detector  86  have fiber optic cables  30  providing the optical communication between optical ports  80  and  82  and optical illuminator  84  and optical detector  86 . 
     As shown in  FIG. 11 , optical illuminator  84  is positioned within illuminating system  81 , and optical detector  86  is positioned within detector/processor system  20  where they transmit and receive an optical signal via fiber optical cable  30 . It is understood that optical illuminator  84  and optical detector  86  may be positioned anywhere they are able to transmit and/or receive the optical signal. Other optical relay methods may be used, by way of a non-limiting example: light pipes, imaging and non-imaging relay optics, close proximity coupling of detector  86  with substrate  16 , or combinations thereof. 
     In the preferred embodiment, fiber optical cable  30  has a first end  90  and a second end  92  to provide illumination. First end  90  is disposed in optical port  80  and/or optical port  82 . Second end  92  is connected to optical illuminator  84  within illumination system  81 . An example of an optical illuminator  84  is a light-emitting diode (LED) having a specific wavelength. As stated, optical port  80  and/or optical port  82  may be positioned above or below substrate  16 . Power for illumination system  81  can be the aforementioned sources of electrical identified for power source  34 . 
     Optical illuminator  84  is preferably capable of generating light in the ultraviolet range to create fluorescing in reporter  38 . Preferably, a plurality of optical illuminators  84  are used to generate a plurality of illuminations. Each of the plurality of illuminations is preferably in a wavelength that is different from each of the other illuminations. In operation, the plurality of illuminators  84  sequentially interrogate reporters  38  to prevent cross-contamination of an optical signal. However, optional programming of optical illuminators  84  provides for the interrogation of reporters  38  in any order. The desired response from reporter  38  determines the order of interrogation. The programmed interrogation of reporters  38  includes the ability to interrogate them simultaneously. 
     In one embodiment, a plurality of optical illuminators  84 , each having a different wavelength, are used to increase the breadth of coverage by using more reporters  38 , thereby increasing the opportunity for detection of a plurality of different analytes. In another embodiment, a plurality of optical detectors  86  are used to increase the opportunity to capture a detection signal, thereby providing for a greater opportunity to verify the identity of the sample substance under scrutiny. In yet another embodiment, a plurality of both optical illuminators  84  and optical detectors  86  are used. 
     In the preferred embodiment, a second fiber optic cable  30  having first and second ends  94  and  96 , provides optical communication between either of optical ports  80  and  82  for optical detector  86 . First end  94  is in optical communication with either of optical ports  80  and  82 . Second end  96  is in optical communication with optical detector  86 . The second fiber optic  30  is not used for illumination purposes, but may be co-located with the first fiber optic cable  30  in either of optical ports  80  and  82  while the first fiber optic cable is used for illumination purposes. Optical detector  86  is capable of converting the optical signal to an electrical signal. Optical detector  86  is positioned within the detector/processor system  20 . Power for optical detector  86  is the aforementioned power source  34 . 
     Preferably, sensor head  39  is positioned to maximize the efficiency of detection system  18 . As shown in  FIG. 3A , sensor head  39  of detection system  18  is angled relative to substrate  16 . The angling increases the surface area of reporter  38  during interrogation. However, sensor head  39  can be also be orthogonal or parallel to reporter(s)  38 . 
     Reporters 
     In a preferred embodiment, detection apparatus  10  simultaneously utilizes numerous reporters  38  on substrate  16  in multiple tracks. Furthermore, each track may include a plurality of reporters  38 . Additionally, detection apparatus  10  may optionally include multiple bright field reporters  38  and multiple dark field reporters  38 . 
     Bright field reporters  38  require active illumination. The response to an analyte produces a detectable change in fluorescence or color. Dark field reporters  38  are commonly chemiluminescent and do not require active illumination. These reporters produce light in response to a target analyte. Dark field reporters  38  do not have any control mechanism turning them on or off. Preferably, when module  14  includes more than one dark field reporter, the dark field reporters will be separated into zones based on the known wavelength of the resulting light. 
     Reporters  38  will vary based upon need, but a representative example includes Amplifying Fluorescence Polymers (AFPs), other fluorescent materials, Chemical Warfare Indicating Chromophore (CWIC), other chemiluminescent materials, Phenyl Quinoline (PQ), polymers, colorimetric materials, organic thin film transistors, metal, metal-oxide based sensors, or a combination thereof As other reporters  38 , or more refined reporters  38 , are developed, they will become candidates for use on substrate  16 . Some reporters  38  are single exposure, but most commonly known reporters  38  are capable of receiving multi-exposures before losing their responsiveness. 
     As stated before, reporters  38  are preferably adhered to substrate  16 . Some methods for depositing reporters  38  to substrate  16  may include ink-jet application, direct deposit, lithography, screen printing, vacuum sealing, heating, laminating, or some other method that provides for the application of multiple reporters  38  on the same substrate  16  and prevents cross-contamination of reporters  38 . Reporters  38  will usually have a thickness in the range of about 0.5 microns to about 0.5 millimeters. 
     Environmental 
     In one embodiment, detection apparatus  10  must be able to operate in closed environments around humans who are not wearing any special protective gear. In another embodiment, detection apparatus  10  must withstand combat deployment conditions such as found in desert, tropical, temperate and cold climates. Additionally, detection apparatus  10  is preferably able to withstand shipping and handling by untrained personnel. Thus, detection apparatus  10  is preferably able to withstand a fall from about a three (3) foot height without adding any additional protection measures. In addition, detection apparatus must withstand repeated bouncing in a closed container. 
     Operational Considerations/Impacts 
     Preferably, detection apparatus  10  employs different modules  14  for different threats. For example, if a detection apparatus is using cartridges  22 , and if there is a threat of an explosive compound or biological substance, the operator selects the cartridge that can detect either of these threats. Alternatively, if the threats relate to chemical warfare agents and explosive compounds, the operator selects a cartridge  22  that is capable of detecting both these threats. However, it is understood, that cartridge  22  may have a series of reporters  38  for detecting a specific threat within a category such as explosives, chemical warfare agents, biological warfare agents, and/or hazardous chemicals. 
     Detection apparatus  10  is usable in the field by personnel having minimal training. Thus, replacing module  14  is preferably an easy task. When cartridge  22  reaches the end of the unexposed substrate  16 , the field personnel are able to remove and insert a new cartridge  22 . In one embodiment, the replacement interval of cartridge  22  is in excess of eight hours. In another embodiment, cartridge  22  (module  14 ) will have a replacement interval of about three to four weeks. Alternatively, the number of exposures or gas samples defines the replacement interval of cartridge  22 . 
     The detectors of detection system  18  determine if contamination of reporter  38  and/or substrate  16  has occurred. For example, photo bleaching or oxidation potentially affects a reporter&#39;s effectiveness. The detectors periodically interrogate reporter  38  to identify the state of reporter  38 . The detectors also monitor the degradation of the brightness of a response from reporter  38 . If the detector finds a contaminated or degraded reporter  38 , control system  36  advances substrate  16  within cartridge  22  to a new, unexposed segment. 
     When a detection event occurs, control system  36  generates a display (not shown) on detection apparatus  10  and/or an electronic signal for transmittal to another device. An audible signal may also be generated. The operator can take appropriate action based upon the type of substance detected in the gas sample. 
     After a detection event is over, pump  54  purges sample area  50  by passing a sufficient quantity of uncontaminated air across sample area  50 . Control system  36  advances substrate  16  within cartridge  22 , presenting a fresh set of reporters  38 . 
     Method 
     A method of use of detection apparatus  10  includes placing it where sample port  26  captures and receives a gas sample carrying at least one analyte. Due to the pressure drop created by pump  54 , the gas sample is communicated from sample port  26  to gas sample inlet  40 , across sample area  50  and reporters  38 , through gas sample outlet  42  and is expelled through exhaust port  28 . The analyte responds to at least one reporter  38  positioned on substrate  16 . 
     In one embodiment, the analyte responds to a bright field reporter  38 . The method includes actively illuminating the bright field reporter  38  with optical illuminator  84 . The active illuminating step occurs within sample area  50 . A non-limiting example uses an ultraviolet LED illuminator  84  that propagates light from illuminating system  81  across the first fiber optic cable  30  to sample area  50 , thereby causing the analyte to fluoresce. Upon response of reporter  38  to the analyte, optical detector  86 , in detector/processor system  20 , detects the change in fluorescence of reporter  38  in response to the analyte. The second fiber optic cable  30  optically communicates the detected change in fluorescence from sample area  50  to optical detector  86 . 
     In another embodiment, the analyte responds to a dark field reporter  38 . Since the dark field reporter  38  is chemiluminescent, optical detector  86  is continually monitoring reporter  38  for a response between reporter  38  and the analyte. In the event a response occurs, reporter  38  emits fluorescence within sample area  50 . Fiber optic cable  30  optically communicates the fluorescence from sample area  50  to optical detector  86  in detection/processor system  20 . 
     For both embodiments, detector/processor system  20  and optical detector  86  process the particular response. And, based upon the prior identification of module  14  and reporters  38  contained therein, notifies control system  36  of the identity of the particular analyte. Display of the resulting identification provides the operator immediate notification of the presence of an analyte in the gas sample. Control system  36  communicates the identity of analyte to the display. Control system  36  records all operations for future reference. Once the event is over, control system  36  communicates to the automated advancing system to advance substrate  16  to an unexposed section. 
     Control system  36  continually monitors module  14 . When all, or substantially all, of substrate  16  is consumed, or mostly consumed, control system  36  notifies the operator of a need to replace module  14 . 
     Other embodiments of the current invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. Thus, the foregoing specification is considered merely exemplary of the current invention with the true scope thereof being defined by the following claims.