Nanowire-based sensor configurations
View Patent ↗This invention provides nanowire based molecular sensors and methods for detecting analytes in a microfluidic system. Methods for sensing analytes include detecting changed electrical parameters associated with contact of a nanowire with the analyte in a microfluidic system. Sensors of the invention include nanowires mounted in microchambers of a microfluidic system in electrical contact with the detector, whereby electrical parameter changes induced in the nanowire by the analyte can be monitored by the detector.
1. A method of detecting an analyte of interest, comprising:
providing a nanowire having a sample exposure region, the sample exposure region comprising at least one binding molecule for an analyte of interest disposed thereon, the nanowire being operably coupled to an electrical parameter detector;
contacting the sample exposure region with a sample material suspected of containing the analyte of interest for a first period of time to allow any analyte of interest in the sample material to associate with the sample exposure region of the nanowire;
treating the nanowire to rapidly remove at least a portion of the analyte of interest from association with the sample exposure region; and
monitoring the electrical parameter of the nanowire during at least the treating step and the removal of at least a portion of the analyte to detect a change in the electrical parameter of the nanowire in response to the treating step, the change in the electrical parameter being indicative of a presence or amount of the analyte of interest bound to the sample exposure region from the sample material.
2. The method of claim 1 , wherein said treating the nanowire comprises exposing the nanowire to ultraviolet light to remove at least a portion of the analyte of interest from association with the sample exposure region.
3. The method of claim 1 , wherein said treating the nanowire comprises exposing the nanowire to heat to remove at least a portion of the analyte of interest from association with the sample exposure region.
4. The method of claim 1 , wherein said treating the nanowire comprises exposing the nanowire to an enzyme to remove at least a portion of the analyte of interest from association with the sample exposure region.
5. The method of claim 1 , wherein said treating the nanowire comprises exposing the nanowire to a wash solution to remove at least a portion of the analyte of interest from association with the sample exposure region.
6. The method of claim 1 , wherein said treating the nanowire comprises exposing the nanowire to an electrical current to remove at least a portion of the analyte of interest from association with the sample exposure region.
7. The method of claim 1 , further comprising exposing the nanowire to a low ionic strength solution prior to monitoring the electrical parameter.
8. The method of claim 1 , wherein the at least one binding molecule includes nucleic acids, peptite nucleic acids, antibodies, receptors, lectins, charged groups and/or chelators.
9. The method of claim 1 , wherein the nanowire is piezoresistive, and wherein the change in the electrical parameter comprises a change in resistance of the piezoresistive nanowire.
10. The method of claim 1 , wherein the nanowire exhibits an electrical field effect to provide a change in the electrical parameter.
11. The method of claim 10 , wherein the nanowire is configured as a gate region in a transistor.
12. The method of claim 1 , further comprising comparing the electrical parameter or the change thereof to that monitored for a control nanowire lacking the at least one binding molecule, and analyzing the comparison to determine background noise or other nonspecific interference.
13. The method of claim 1 , wherein the electrical parameter is resistance.
14. The method of claim 1 , wherein the electrical parameter is voltage.
15. The method of claim 1 , wherein the electrical parameter is current.
16. A method of detecting an analyte of interest, comprising:
providing a nanowire having a sample exposure region, the sample exposure region comprising at least one binding molecule for an analyte of interest disposed thereon, the nanowire being operably coupled to an electrical parameter detector;
contacting the sample exposure region with a sample material suspected of containing the analyte of interest for a first period of time to allow any analyte of interest in the sample material to associate with the sample exposure region of the nanowire;
treating the nanowire to rapidly remove at least a portion of the analyte of interest from association with the sample exposure region; and
monitoring the electrical parameter of the nanowire during at least the treating step to detect a change in the electrical parameter of the nanowire in response to the treating step, the change in the electrical parameter being indicative of a presence or amount of the analyte of interest bound to the sample exposure region from the sample material.
17. The method of claim 16 , wherein the electrical parameter is electrical resistance.
18. The method of claim 16 , wherein the electrical parameter is resistance.
19. The method of claim 16 , wherein the electrical parameter is voltage.
20. The method of claim 16 , wherein the electrical parameter is current.
21. The method of claim 16 , wherein the nanowire is configured as a gate region in a transistor.
22. The method of claim 16 , wherein the treating step is done after a plurality of the analytes are bound to the nanowire.