MODIFICATION OF SELECTIVITY FOR SENSING FOR NANOSTRUCTURE SENSING DEVICE ARRAYS

• US 20110003698A1
• Filed: 11/09/2007
• Published: 01/06/2011
• Est. Priority Date: 03/15/2002
• Status: Active Grant

• Current Assignee: Nanomix Incorporated (CJY Holdings Ltd.)
• Original Assignee: Nanomix Incorporated (CJY Holdings Ltd.)
• Inventors: Bradley, Keith, Gruner, George, Gabriel, Jean-Christophe P., Collins, Philip G.
• Granted Patent: US 8,900,517 B2
• Time in Patent Office: Days
• US Class Current: 506/7
• CPC Class Codes: G01N 2035/00158 Elements containing microarrays, i.e. "biochip"
• CPC Class Codes: G01N 27/4146 involving nanosized elements, e.g. nanotubes, nanowires
• CPC Class Codes: Y10S 977/70 Nanostructure
• CPC Class Codes: Y10S 977/701 Integrated with dissimilar structures on a common substrate
• CPC Class Codes: Y10S 977/84 Manufacture, treatment, or detection of nanostructure
• CPC Class Codes: Y10S 977/882 Assembling of separate components, e.g. by attaching
• CPC Class Codes: Y10S 977/883 Fluidic self-assembly, FSA
• CPC Class Codes: Y10S 977/902 Specified use of nanostructure
• CPC Class Codes: Y10S 977/92 Detection of biochemical
• CPC Class Codes: Y10S 977/953 Detector using nanostructure
• CPC Class Codes: Y10S 977/957 Of chemical property or presence
• CPC Class Codes: Y10T 29/49 Method of mechanical manufacture
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 436/11 Automated chemical analysis

Abstract

An electronic system for selectively detecting and identifying a plurality of chemical species, which comprises an array of nanostructure sensing devices, is disclosed. Within the array, there are at least two different selectivities for sensing among the nanostructure sensing devices. Methods for fabricating the electronic system are also disclosed. The methods involve modifying nanostructures within the devices to have different selectivity for sensing chemical species. Modification can involve chemical, electrochemical, and self-limiting point defect reactions. Reactants for these reactions can be supplied using a bath method or a chemical jet method. Methods for using the arrays of nanostructure sensing devices to detect and identify a plurality of chemical species are also provided. The methods involve comparing signals from nanostructure sensing devices that have not been exposed to the chemical species of interest with signals from nanostructure sensing devices that have been exposed to the chemical species of interest.

Claims

1. An electronic system for selectively detecting and identifying a plurality of chemical species, comprising an array of nanostructure sensing devices, each nanostructure sensing device comprising at least one nanostructure and having a selectivity for sensing the chemical species, wherein the selectivity of the at least one nanostructure sensing device differs from the selectivity of at least one other nanostructure sensing device.

2. The electronic system of claim 1, further comprising, in each nanostructure sensing device, at least two contact electrodes, the at least two contact electrodes electrically connected by the at least one nanostructure.

3. The electronic system of claim 2, wherein the at least two contact electrodes comprise a material selected from the group consisting of aluminum, copper, titanium and tungsten.

4. The electronic system of claim 2, further comprising a protective coating on the at least two contact electrodes.

5. The electronic system of claim 4 wherein the protective coating is selected from the group consisting of silicon oxides, metal oxides, polymer films, and nonvolatile organics.

6. The electronic system of claim 2, further comprising a gate electrode in at least a portion of the nanostructure sensing devices in the array of nanostructure sensing devices.

7. The electronic system of claim 2, further comprising a counter electrode, electrically isolated from the contact electrodes, in at least a portion of the nanostructure sensing devices in the array of nanostructure sensing devices.

8. The electronic system of claim 7, further comprising a pseudo-reference electrode, electrically isolated from the contact electrodes, in at least a portion of the nanostructure sensing devices.

9. The electronic system of claim 1, wherein the nanostructure sensing devices comprise at least one nanostructure selected from the group consisting of single-walled nanotubes, multi-walled nanotubes, nanofibers, nanowires, nanocoils, nanospheres, nanocages, nanococoons, nanohorns, nanoropes, nanotori, nanorods, nanoplatelets, and other extended molecules such as polymers, dendrimers, organometallics, fullerene-like molecules, and combinations thereof.

10. The electronic system of claim 1, wherein the nanostructure sensing devices comprise at least one nanostructure comprising an approximately linear form.

11. The electronic system of claim 1, wherein the nanostructure sensing devices comprising at least one nanostructure comprises elements selected from the group consisting of boron, carbon, combinations thereof, and combinations with nitrogen.

12. The electronic system of claim 1, further comprising at least two nanostructure sensing devices having the same selectivity for sensing, wherein at least one of the at least two nanostructure sensing devices is impermeably shielded from at least the plurality of chemical species, and at least one of the at least two nanostructure sensing devices is at least partially exposed to at least the plurality of chemical species.

13. A method of making a system for selectively detecting and identifying a predetermined number of chemical species, comprising the steps of:

(a) providing an array of nanostructure sensing devices, each nanostructure sensing device comprising at least one nanostructure and at least two contact electrodes, wherein the at least one nanostructure provides electrical coupling between the at least two contact electrodes;

(b) providing at least one counter electrode;

(c) submerging at least the portion of the nanostructure sensing devices in an electrochemical solution;

(d) applying a first voltage to the contact electrodes in at least the portion of nanostructure sensing devices;

(e) applying a second voltage, different from the first voltage, to the at least one counter electrode, thus effecting an electrochemical reaction between the electrochemical solution and the at least one nanostructure in each nanostructure sensing device; and

(f) rinsing the electrochemical solution from at least the portion of the array of nanostructure sensing devices after applying the second voltage.

14. The method of claim 13, further comprising performing at least steps (a) through (e) repeatedly using different electrochemical solutions and applying different first voltages and second voltages until there is a variety of selectivity for sensing within the array of nanostructure sensing devices such that each of the predetermined number of chemical species produces a measurable signal from the array.

15. The method of claim 13, wherein providing the at least one counter electrode comprises providing a counter electrode in each nanostructure sensing device in at least a portion of the nanostructure sensing devices in the array.

16. The method of claim 13, wherein providing the at least one counter electrode comprises providing at least one counter electrode in the electrochemical solution.

17. The method of claim 13, further comprising, before step (c), providing a pseudo-electrode in each nanostructure sensing device in at least the portion of the array of nanostructure sensing devices.

18. The method of claim 13, further comprising, before step (d), providing a pseudo-electrode in the electrochemical solution.

19. The method of claim 13, further comprising supplying energy to the reactant.

20. The method of claim 19, wherein the energy is selected from the group consisting of ultraviolet radiation, thermal energy, and electrical energy.

21. A method for detecting a plurality of chemical species in a surrounding environment, comprising:

measuring first signals from nanostructure sensing devices in an array of nanostructure sensing devices before exposing the array to a surrounding environment, wherein the nanostructure sensing devices have selectivity for sensing chemical species, the selectivity of the at least one nanostructure sensing device differing from the selectivity of at least one other nanostructure sensing device in the array;

measuring second signals from nanostructure sensing devices in an array of nanostructure sensing devices after exposing the array to the surrounding environment, wherein a significant change between the first signal and the second signal for a particular nanostructure sensing device indicates detection of a chemical species;

making correlations between known signal changes between first signals and second signals, which occur when known chemical species are detected and observed changes between the first signals and the second signals; and

interpreting the correlations to identify chemical species in the surrounding environment.

22. The method of claim 21, wherein the signals are selected from the group consisting of electrical signals, optical signals, mechanical signals, and thermal signals.

23. The method of claim 21, further comprising applying and maintaining a first gate voltage to a gate electrode associated with each nanostructure sensing device in at least a first portion of the array of nanostructure sensing devices before measuring the first signals from at least the first portion of the array and continuing to maintain the first gate voltage throughout measuring the second signals from at least the first portion of the array.

24. The method of claim 23, further comprising applying and maintaining a second gate voltage, different from the first gate voltage, to a gate electrode associated with each nanostructure sensing device in at least a second portion of the array of nanostructure sensing devices before measuring the first signals from at least the second portion of the array and continuing to maintain the second gate voltage throughout measuring the second signals from at least the second portion of the array.

25. The method of claim 21, further comprising applying a series of gate voltages to a gate electrode associated with each nanostructure sensing device in at least a portion of the array of nanostructure sensing devices and measuring the first signals and the second signals from at least the portion of the array of nanostructure sensing devices at each gate voltage.

26. A method for detecting a plurality of chemical species in an environment of interest, comprising:

providing an array of sets of nanostructure sensing devices, each set comprising at least two nanostructure sensing devices, such that the at least two nanostructure sensing devices have a same selectivity for sensing;

providing shielding impermeable to at least the plurality of chemical species to at least one of the at least two nanostructure sensing devices in each set and allowing at least one of the at least two nanostructure sensing devices in each set to be at least partially exposed to at least the plurality of chemical species;

measuring and comparing signals from the at least two nanostructure sensing devices in each set after positioning the array in the environment of interest;

making correlations between known signal differences for shielded and at least partially exposed nanostructure sensing devices in a set when known chemical species are detected and observed differences in signals for shielded nanostructure sensing devices and at least partially exposed nanostructure sensing devices in each set; and

interpreting the correlations to identify chemical species in the environment of interest.

27. The method of claim 26, wherein the signals are selected from the group consisting of electrical signals, optical signals, mechanical signals, and thermal signals.

28. The method of claim 26, further comprising applying a first gate voltage to gate electrodes associated with each of the at least two nanostructure sensing devices in each set in at least a first portion of the array of sets before and throughout measuring and comparing signals from the at least two nanostructure sensing devices in each set.

29. The method of claim 28, further comprising applying a second gate voltage, different from the first gate voltage, to gate electrodes associated with each of the at least two nanostructure sensing devices in each set in at least a second portion of the array of sets before and throughout measuring and comparing the signals from the at least two nanostructure sensing devices in each set.

30. The method of claim 26, further comprising applying a series of gate voltages to gate electrodes associated with each of the at least two nanostructure sensing devices in each set in at least a portion of the array of sets and measuring and comparing the signals from the at least two nanostructure sensing devices in each set at each gate voltage.