Micro scale flow through sorbent plate collection device

Abstract

In the invention, a collection device includes a first micro scale plate having a sorbent surface and a through hole. The through hole provides for the passage of an analyte fluid flow through the plate, and it has a volume and geometry to provide contact between the fluid and the sorbent surface in an amount effective to absorb a sufficient amount of analyte for subsequent detection of the analyte. The sorbent surface can be provided by a sorbent coating such as an active sensing film, e.g. a conducting or optically active material, examples of which include conducting polymers, polymer/carbon composites, carbon nanotubes, and dye-containing materials. The analyte collection device preferably includes a heating source, e.g. a heating element formed from a resistive trace, or a plurality of resistive traces, on or within the first microscale plate, for effecting a thermal release of collected analyte from the plate.

1 . An analyte collection device, the device comprising: 
 a first micro scale plate having a sorbent surface; and    a through hole through said first microscale plate, said hole being arranged to permit passage of an analyte fluid flow through said first microscale plate and whereby said hole has a volume and geometry to provide contact between said fluid and said sorbent surface in an amount effective to absorb said analyte thereon in an amount effective for detection.    
     
     
         2 . The analyte collection device of  claim 1 , further comprising a heating source for effecting a thermal release of said collected analyte from said first microscale plate.  
     
     
         3 . The analyte collection device of  claim 2 , wherein said heating source is a heating element comprising a resistive trace formed on or within said first microscale plate.  
     
     
         4 . The analyte collection device of  claim 3 , wherein: 
 said heating element comprises a plurality of resistive traces formed on or within said first microscale plate;    wherein said resistive traces divide said microscale plate into a plurality of zones, one of said zones being a collection zone for collecting analyte from environment, and another being a smaller delivery zone for concentrating analyte from the collection zone in a smaller area and delivering analyte to a detector system.    
     
     
         5 . The analyte collection device of  claim 4 , wherein the sorbent surface comprises a sorbent coating that is thicker in said smaller delivery zone than in said collection zone.  
     
     
         6 . The analyte collection device of  claim 1 , further comprising a plurality of through holes through said first microscale plate.  
     
     
         7 . The analyte collection device of  claim 1 , wherein the sorbent surface comprises a sorbent coating on at least a portion of said first microscale plate.  
     
     
         8 . The analyte collection device of  claim 7 , wherein the sorbent coating is an active sensing film selected from the group consisting of conducting and optically active materials.  
     
     
         9 . The analyte collection device of  claim 8 , wherein the sorbent coating is selected from the group consisting of conducting polymers, polymer/carbon composites, carbon nanotubes, and dye-containing materials.  
     
     
         10 . The analyte collection device of  claim 9 , comprising multiple sorbent coatings formed in multiple zones of said first microscale plate, each sorbent coating being selected to sorb a predetermined analyte.  
     
     
         11 . The analyte collection device of  claim 10 , further comprising a heating element for each of said multiple zones.  
     
     
         12 . The analyte collection device of  claim 11 , further comprising a sorbent coating for each of said multiple zones and wherein each said coating comprises a bioreceptor site selected for collecting a desired biorelated analyte.  
     
     
         13 . The analyte collection device of  claim 7 , wherein said device further comprises a means of delivering analyte into one of a capillary gas chromatographic column, a mass spectrometer, and a micro sensor having a pneumatic manifold opening.  
     
     
         14 . The analyte collection device of  claim 1 , further comprising a second micro scale plate with a sorbent surface, a through hole, and heating source, said second microscale plate being arranged downstream of said first micro scale plate such that an analyte fluid flow substantially through said first micro scale plate is also directed through said second microscale plate.  
     
     
         15 . The analyte collection device of  claim 14 , wherein each of said first and second micro scale plates comprises a plurality of through holes.  
     
     
         16 . The analyte collection device of  claim 15 , wherein said through holes through said first micro scale plate are at least partially aligned with solid portions of said second micro scale plate to induce a cascading flow of analyte fluid through said first and second micro scale plates.  
     
     
         17 . The analyte collection device of  claim 16 , further comprising a plurality of microscale plates each having a sorbent surface, a heating source, and a plurality of through holes.  
     
     
         18 . The analyte collection device of  claim 17 , wherein the heating source for each of said microscale plates is a resistive heating trace independently controlled by a microcontroller.  
     
     
         19 . The analyte collection device of  claim 18 , wherein the microcontroller is configured to deliver a pulse width modulation (PWM) signal to each heating trace.  
     
     
         20 . The analyte collection device of  claim 19 , wherein during off pulses of the PWM signal each said heater trace is switched into a measuring circuit that provides a signal proportional to the temperature of the heater trace for regulating the temperature of the heater trace.  
     
     
         21 . The analyte collection device of  claim 20 , wherein the microcontroller is configured to perform the switching of said heater trace into said measuring circuit and adjust the PWM signal to place the heater trace at a desired temperature.  
     
     
         22 . The analyte collection device of  claim 21 , wherein the microcontroller function controls activation of a system pump, a valve, and pneumatics.  
     
     
         23 . The analyte collection device of  claim 17 , wherein each of said microscale plates is positioned in a stack configuration and is sized such that each collection surface of each plate is smaller than an adjacent preceding plate and is larger than an adjacent following plate in said stack whereby a boundary surface contains and directs fluid flow between plates in a direction from a large plate towards a smaller plate.  
     
     
         24 . The analyte collection device of  claim 11 , further comprising: 
 a detector system;    a power source; and    a controller;    thereby forming a self contained microanalytical system.    
     
     
         25 . The analyte collection device of  claim 24 , further comprising: 
 a housing for the collection device;    an inlet to said housing;    an outlet from said housing; and    means for inducing the analyte fluid flow.    
     
     
         26 . The analyte collection device of  claim 25 , wherein said means for inducing comprise a low power fan.  
     
     
         27 . The analyte collection device of  claim 1 , wherein said first micro scale plate is formed from a semiconductor material, a conducting material, or an insulator.  
     
     
         28 . The analyte collection device of  claim 27 , wherein said first semiconductor material comprises silicon.  
     
     
         29 . The device of  claim 1 , wherein said through hole comprises a plurality of through holes taking up approximately 40-60% of the surface area of said first micro scale plate.  
     
     
         30 . The analyte collection device of  claim 1 , further comprising a means of introducing collected biorelated analytes into a biomaterial detection system.  
     
     
         31 . The analyte collection device of  claim 1 , wherein the sorbent surface comprises a sorbent coating on at least a portion of said first microscale plate with analyte collection performed passively absent a pump-directed fluid flow.  
     
     
         32 . The analyte collection device of  claim 1 , wherein the sorbent surface comprises a sorbent coating on at least a portion of said first microscale plate and an integrated sensing device on said first microscale plate.  
     
     
         33 . An analyte collection device, the device comprising: 
 a first micro scale plate;    a through hole through said first microscale plate, said hole being arranged to permit passage of an analyte fluid flow through said first microscale plate;    a first resistive trace forming a first heating element defining a first zone on said microscale plate;    a second resistive trace forming a second heating element defining a second zone on said microscale plate; and    a sorbent coating formed on at least a portion of said first zone and a portion of said second zone.    
     
     
         34 . The device of  claim 33 , wherein said sorbent coating is formed thicker in said second zone.  
     
     
         35 . The device of  claim 34 , wherein said second zone is smaller than said first zone.  
     
     
         36 . A method for concentrating analyte from an analyte fluid flow and delivering the analyte, the method comprising the steps of: 
 directing the analyte fluid flow substantially perpendicular to a micro scale sorbent coated plate and through holes in the micro scale sorbent coated plate to concentrate analyte in the sorbent;    heating the sorbent; and    delivering analyte desorbed due to said heating in a flow substantially parallel to said microscale sorbent coated plate.    
     
     
         37 . The method of  claim 36 , wherein said step of directing uses a high analyte fluid flow and said step of delivering uses a low flow substantially parallel to said microscale sorbent coated plate.