Device, method, and system for separation and detection of biomolecules and cells

Abstract

Embodiments of the invention relate to device, method, and system for separation and/or detection of biological cells and biomolecules using micro-channels, magnetic interactions, and magnetic tunnel junctions. The micro-channels can be integrated into a microfluidic device that may be part of an integrated circuit. Magnetic interactions used for the separation are created, in part, by magnetic stripes associated with the micro-channels. Detection of biological cells and biomolecules is effectuated by a magnetic tunnel junction sensor that comprises two ferromagnetic layers separated by a thin insulating layer. The magnetic tunnel junction sensor can be integrated into a silicon based device, such a microfluidic device, an integrated circuit, or a microarray to achieve rapid and specific separation and/or detection of biomolecules and cells.

1 - 35 . (canceled) 
     
     
         36 . A device comprising a closed micro-channel, two ferromagnetic metal layers separated by an insulating layer, a magnetic stripe formed in association with the micro-channel; wherein the device is capable of functioning as a magnetic tunnel junction and wherein the magnetoresistance of the device changes when the device is exposed to a magnetically tagged biomolecule or cell; wherein the magnetic stripe comprises a material selected from a group consisting of permanent magnetic materials, ferromagnetic materials, and a combination thereof. 
     
     
         37 . The device of  claim 36 , wherein the device further comprises an anti-ferromagnetic coupling layer. 
     
     
         38 . The device of  claim 37 , wherein the anti-ferromagnetic coupling layer comprises one or more of IrMn, NiMn, FeMn, and NiO. 
     
     
         39 . The device of  claim 36 , wherein the device is based a silicon substrate. 
     
     
         40 . The device of  claim 39 , wherein the device and the silicon substrate are joined by an adhesive layer. 
     
     
         41 . The device of  claim 39 , wherein the silicon substrate comprises an integrated circuit die. 
     
     
         42 . The device of  claim 36 , wherein the two ferromagnetic layers each independently comprises one or more of nickel, iron, and cobalt. 
     
     
         43 . The device of  claim 36 , wherein the two ferromagnetic metal layers each has a thickness of between 1 nm and 500 nm. 
     
     
         44 . The device of  claim 43 , wherein the two ferromagnetic metal layers each has a thickness of between 5 nm and 50 nm. 
     
     
         45 . The device of  claim 36 , wherein the insulating layer has a thickness of between 0.1 nm and 10 nm. 
     
     
         46 . The device of  claim 45 , wherein the insulating layer has a thickness of between 0.5 nm and 5 nm. 
     
     
         47 . The device of  claim 36 , wherein the insulating layer comprises Al 2 O 3  or MgO. 
     
     
         48 . The device of  claim 36 , wherein the biomolecule or cell is tagged with a magnetic nanoparticle. 
     
     
         49 - 68 . (canceled) 
     
     
         69 . The device of  claim 36 , further comprising a molecular probe attached to at least one of the two ferromagnetic metal layers. 
     
     
         70 . The device of  claim 36 , wherein the closed micro-channel is associated with not more than one magnetic stripe. 
     
     
         71 . The device of  claim 36 , wherein the device further comprises an inlet fluid reservoir in fluid communication with at least one opening of the microchannel; and an outlet fluid reservoir in fluid communication with at least another opening of the micro-channel.