Method and apparatus for detection of analyte using a flexural plate wave device and magnetic particles

Abstract

A system for detecting an analyte in a sample includes a resonant sensor that has a sensor surface coated with the capture agent. A plurality of magnetic particles, each of which is coated with a capture agent having an affinity for the analyte, is combined with the sample to form a plurality of analyte-particle complexes. The system also includes a transport arrangement for transporting the sample to the sensor surface, and a magnetic field inducing structure constructed and arranged to establish a magnetic field at and adjacent to the sensor surface. The resonant sensor produces a signal corresponding to an amount of analyte-particle complexes that are bound to the sensor surface.

1 - 21 . (canceled)  
     
     
         22 . A method for detection of an analyte, comprising: 
 combining a fluid containing an analyte with a plurality of magnetic particles that comprise a capture agent having an affinity for the analyte to produce at least some magnetic particles bound to at least some analyte;    directing the combined fluid into a first fluid chamber, wherein at least one surface of a flexural plate wave device is in fluid communication with the fluid in the first fluid chamber; and    creating a first magnetic flux in proximity to the flexural plate wave device to magnetically attract at least some of the plurality of bound magnetic particles to the at least one surface of the flexural plate wave device.    
     
     
         23 . The method of  claim 22 , further comprising selectively altering at least one of the first magnetic flux in proximity to the at least one surface of the flexural plate wave device or altering at least one property of fluid flow in proximity to the at least one surface of the flexural plate wave device to selectively locate at least some of the plurality of bound magnetic particles on at least a portion of the at least one surface of the flexural plate wave device.  
     
     
         24 . The method of  claim 23  wherein the at least one property of the fluid flow is selected from the group consisting of fluid pressure, flow rate, and fluid trajectory.  
     
     
         25 . The method of  claim 23  wherein altering the at least one property of fluid flow comprises altering a flow path of the fluid to control the movement of the magnetic particles in vicinity to the at least one surface of the flexural plate wave device.  
     
     
         26 . The method of  claim 22 , further comprising applying a second magnetic flux in opposition to the first magnetic flux.  
     
     
         27 . The method of  claim 26 , further comprising changing the second magnetic flux to selectively dislodge at least some of the magnetic particles not bound to analyte from the at least one surface of the flexural plate wave device.  
     
     
         28 . The method of  claim 22 , further comprising terminating the first magnetic flux and creating a second magnetic flux to selectively remove some of the magnetic particles from the at least one surface of the flexural plate wave device.  
     
     
         29 . The method of  claim 22 , further comprising exciting the flexural plate wave device to selectively dislodge materials adhering to the at least one surface of the flexural plate wave device.  
     
     
         30 . The method of  claim 22 , further comprising characterizing a property of the magnetic particles attracted to the at least one interior surface.  
     
     
         31 . The method of  claim 22 , further comprising filtering the combined fluid prior to directing the combined fluid into the first fluid chamber.  
     
     
         32 . The method of  claim 22  wherein directing the combined fluid into the first fluid chamber comprises pumping the combined fluid into a first opening of the first fluid chamber and out of a second opening in the first fluid chamber.  
     
     
         33 . The method of  claim 22  wherein directing the combined fluid into the first fluid chamber comprises flowing the combined fluid into a first opening of the first fluid chamber.  
     
     
         34 . The method of  claim 22  wherein first fluid chamber is located in a cartridge and the fluid containing the analyte and at least some of the plurality of magnetic particles that comprise the capture agent are combined in a second fluid chamber of the cartridge prior to directing the combined fluid into the first fluid chamber.  
     
     
         35 . The method of  claim 22 , further comprising directing at least a portion of the combined fluid out of an opening in the first fluid chamber.  
     
     
         36 . The method of  claim 22  wherein directing the combined fluid into the first fluid chamber comprises immersing a cartridge comprising the first fluid chamber into a vessel containing the combined fluid.  
     
     
         37 . The method of  claim 22 , further comprising selectively altering at least one of the first magnetic flux in proximity to the at least one surface of the flexural plate wave device or altering at least one property of fluid flow in proximity to the at least one surface of the flexural plate wave device to selectively remove from the first fluid chamber, substances located within the combined fluid.  
     
     
         38 . The method of  claim 37  wherein the substances are selected from the group consisting of magnetic particles, analyte, bound magnetic particles, and combinations thereof.  
     
     
         39 - 43 . (canceled)