Methods and compositions for detecting analytes

Abstract

The present application is generally directed to systems, methods, and devices for diagnostics for sensing and/or identifying pathogens, genomic materials, proteins, and/or other small molecules or biomarkers. In some implementations, a small footprint low cost device provides rapid and robust sensing and identification. Such a device may utilize microfluidics, biochemistry, and electronics to detect one or more targets at once in the field and closer to or at the point of care.

1 . (canceled) 
     
     
         2 . A device for testing a sample for a target agent, the device comprising:
 a sample introduction area configured to receive a sample comprising the target agent;   a test well containing an excitation electrode and a sensing electrode, wherein the test well is configured to:
 contain the sample during an amplification process, 
 apply a current to the sample during the amplification process using the excitation electrode, and 
 sense a signal using the sensing electrode, the signal representing the current after attenuation by at least the sample within the test well; and 
   a fluid path fluidically coupling the sample introduction area to the test well.   
     
     
         3 . The device of  claim 2 , further comprising:
 a sealed chamber containing liquid constituents of the amplification process, the sealed chamber positioned in a region of the device having an aperture leading into the fluid path, wherein the sample introduction area is positioned between the aperture and the test well along the fluid path; and   dried constituents of the amplification process provided within the test well.   
     
     
         4 . The device of  claim 3 , further comprising:
 a sharp configured to rupture the sealed chamber and cause the liquid constituents to flow into the region; and   a pneumatic fluid path fluidically coupling a pneumatic interface to the region of the device, the pneumatic fluid path configured to apply pressure to the region to cause the liquid constituents to flow into the fluid path and carry the sample received at the sample introduction area to the test well.   
     
     
         5 . The device of  claim 4 , further comprising a mixing chamber positioned between the sample introduction area and the test well along the fluid path, the mixing chamber configured to mix the liquid constituents and the sample into a substantially evenly mixed test fluid. 
     
     
         6 . The device of  claim 2 , wherein the device comprises a first electrode interface including a first contact pad leading to the excitation electrode and a second contact pad leading to the sensing electrode. 
     
     
         7 . The device of  claim 2 , further comprising a circuit board including the excitation electrode and the sensing electrode, wherein the sample introduction area and at least a portion of the fluid path are formed in a unitary piece of a liquid impermeable material, and wherein the circuit board is adhered to a portion of the liquid impermeable material. 
     
     
         8 . The device of  claim 7 , further comprising a cover positioned over the liquid impermeable material and the circuit board, the cover comprising an aperture positioned over the sample introduction area and a cap configured to releasably seal the aperture. 
     
     
         9 . The device of  claim 8 , wherein sides of the test well are formed as a circular aperture through the liquid impermeable material, and wherein a bottom of the test well is formed by the circuit board. 
     
     
         10 . The device of  claim 9 , wherein the excitation electrode and the sensing electrode are positioned on the bottom of the test well and away from the sides of the test well. 
     
     
         11 . The device of  claim 2 , further comprising a vent configured to release gas from the test well, wherein the vent is covered by a liquid impermeable, gas permeable filter. 
     
     
         12 . The device of  claim 2 , wherein the excitation electrode comprises a circular electrode disposed within the center of the test well and wherein the sensing electrode comprises an annular electrode positioned concentrically around the excitation electrode. 
     
     
         13 . The device of  claim 2 , wherein the excitation electrode comprises a first semicircular electrode and wherein the sensing electrode comprises a second semicircular electrode separated by a gap from the first semicircular electrode, wherein straight portions of the first and second semicircular electrodes face each other across the gap. 
     
     
         14 . The device of  claim 2 , wherein the amplification process comprises contacting the processed sample with a capture probe. 
     
     
         15 . The device of  claim 14 , wherein the capture probe is selected from the group consisting of an antibody or an antigen-binding fragment thereof, a protein receptor, and a nucleic acid. 
     
     
         16 . The device of  claim 2 , wherein the amplification process comprises isothermal amplification. 
     
     
         17 . The device of  claim 2 , wherein the amplification process comprises an isothermal amplification reaction selected from the group consisting of self-sustaining sequence replication reaction (3SR); 90-I; BAD Amp; cross priming amplification (CPA); isothermal exponential amplification reaction (EXPAR); isothermal chimeric primer initiated amplification of nucleic acids (ICAN); isothermal multi displacement amplification (IMDA); ligation-mediated SDA; multi displacement amplification; polymerase spiral reaction (PSR); restriction cascade exponential amplification (RCEA); smart amplification process (SMAP2); single primer isothermal amplification (SPIA); transcription-based amplification system (TAS); transcription meditated amplification (TMA); ligase chain reaction (LCR); and multiple cross displacement amplification (MCDA). 
     
     
         18 . The device of  claim 2 , wherein the amplification process comprises loop-mediated isothermal amplification (LAMP). 
     
     
         19 . The device of  claim 2 , wherein the test well is configured to heat the sample to a temperature greater than 30° C. 
     
     
         20 . The device of  claim 2 , wherein liquid constituents of the amplification process comprise a component selected from the group consisting of an antibody or an antigen-binding fragment thereof, a protein receptor, a nucleic acid such as a primer, a buffer, and an enzyme such as a polymerase. 
     
     
         21 . The device of  claim 2 , wherein dried constituents of the amplification process comprise a component selected from the group consisting of an antibody or an antigen-binding fragment thereof, a protein receptor, a nucleic acid such as a primer, a buffer, and an enzyme such as a polymerase.