Systems And Methods For Electronic Detection With Nanofets

Abstract

There is disclosed a system for electrical charge detection comprising a nanoFET device. Also disclosed is a method of electrical charge detection for single molecule sequencing. The method includes attaching a macromolecule or assemblies thereof to a gate of a nanoFET device and flowing in a solution of charge tags, where a charge tag includes a nucleotide attached to a charge complex. The method also includes incorporating one charge tag into the macromolecule or assemblies thereof and cleaving the charge tags from the macromolecule or assemblies thereof. The method further includes detecting at least one of current and voltage from the nanoFET device.

1 .- 30 . (canceled) 
     
     
         31 . A method of sequencing a nucleic acid strand, the method comprising:
 attaching a polymerase enzyme to a surface of a device, the device having at least one nanoFET having a source, a drain, and a gate, the polymerase enzyme disposed over the gate;   applying the nucleic acid strand to the device following attaching the polymerase enzyme to the surface, the nucleic acid strand forming an assembly with the polymerase enzyme;   following applying the nucleic acid strand, applying a charge labeled probe to be incorporated in response to a sequence of the nucleic acid strand, the charge labeled probe including a nucleotide complementary to a next base in the sequence and a charge tag linked to the nucleotide; and   detecting the charge tag.   
     
     
         32 . The method of  claim 31 , wherein detecting the charge tag includes applying an alternating current field. 
     
     
         33 . The method of  claim 33 , wherein the alternating current field matches a resonance of a dipole of the charge tag. 
     
     
         34 . The method of  claim 33 , wherein applying the alternating current field includes varying the alternating current field. 
     
     
         35 . The method of  claim 33 , wherein applying the alternating current field includes applying the alternating current field in pulsed square waves. 
     
     
         36 . The method of  claim 31 , wherein the strand of nucleic acids is a strand of target DNA. 
     
     
         37 . The method of  claim 31 , wherein applying a charge labeled probe includes flowing a solution of charge labeled probes, the method further comprising removing the solution of charge labeled probes and any unincorporated charge labeled probes prior to detecting. 
     
     
         38 . The method of  claim 31 , further comprising applying a primer complementary to a portion of the nucleic acid strand prior to applying the charge labeled probe, the primer hybridizing to the nucleic acid strand. 
     
     
         39 . The method of  claim 38 , wherein the primer and the charge labeled probe ligate to form a second nucleic acid strand, the method further comprising:
 removing the second nucleic acid strand; and   adding a second primer configured to detect bases shifted by one base relative to the primer,   hybridizing said second primer to the nucleic acid strand; and   adding a solution of charged labeled probes.   
     
     
         40 . The method of  claim 39 , further comprising:
 incorporating a second charge labeled probe of the solution of charge labeled probes; and   detecting a second charge tag.   
     
     
         41 . The method of  claim 31 , further comprising applying a voltage bias to drive the charge labeled probe toward or away from the nanoFET device. 
     
     
         42 . The method of  claim 31 , further comprising cleaving the charge tag from the incorporated charge labeled probe. 
     
     
         43 . The method of  claim 42 , wherein the charge tag linked to the charge labeled probe is photocleavable. 
     
     
         44 . The method of  claim 42 , wherein cleaving the charge tag includes activating a light source. 
     
     
         45 . The method of  claim 44 , wherein activating the light source includes localizing the light source using total internal reflection. 
     
     
         46 . The method of  claim 44 , wherein activating the light source includes scanning a line source or point source across an array of nanoFETs. 
     
     
         47 . The method of  claim 31 , wherein the charge tag linked to the charge labeled probe is chemically cleavable. 
     
     
         48 . A method of sequencing a nucleic acid strand, the method comprising:
 attaching a polymerase enzyme to a surface of a device, the device having at least one nanoFET having a source, a drain, and a gate, the polymerase enzyme disposed over the gate;   applying the nucleic acid strand to the device following attaching the polymerase enzyme to the surface, the nucleic acid strand forming an assembly with the polymerase enzyme;   applying a primer complementary to a portion of the nucleic acid strand, the primer hybridizing to the nucleic acid strand;   following applying the nucleic acid strand and the primer, adding a solution including a plurality of charge labeled probes, each charge labeled probe including a nucleotide and a charge tag linked to the nucleotide, a charge labeled probe of the plurality of charge labeled probes to be incorporated in response to a sequence of the nucleic acid strand, the charge labeled probe including a nucleotide complementary to a next based in the sequence; and   detecting the charge tag by applying an alternating current field.   
     
     
         49 . The method of  claim 33 , wherein the alternating current field matches a resonance of a dipole of the charge tag of the charge labeled probe. 
     
     
         50 . The method of  claim 33 , wherein applying the alternating current field includes varying the alternating current field.