Functionalized nanostructures for detecting nitro-containing compounds

Abstract

Devices, methods and systems for detecting nitro-containing compounds such as TNT, which utilize semiconductor nanostructures modified by a functional moiety that interacts with the nitro-containing compound, are disclosed. The functional moiety is attached to the nanostructures and is being such that upon contacting a sample that contains the nitro-containing compound, the nanostructure exhibits a detectable change in an electrical property, which is indicative of the presence and/or amount of the nitro-containing compound in the sample. Electronic noses for generating recognition patterns of various nitro-containing compounds, made of a plurality of nanostructures modified by versatile functional moieties are also disclosed. The devices, methods and systems are suitable for detecting nitro-containing compounds in both liquid and gaseous states and for detecting a concentration of a nitro-containing compound such as TNT as low as attomolar concentrations.

What is claimed is: 
     
         1 . A method of determining a presence and/or an amount of a nitro-containing compound is a sample, the method comprising contacting the sample with a device comprising a semiconductor nanostructure and a functional moiety attached to said nanostructure, wherein said functional moiety has a length smaller than 2 nm, is an electron-donating moiety, and interacts with the nitro-containing compound by forming a charge transfer complex and, and wherein said nanostructure is selected from a nanowire and a nanotube, and is disposed between a source electrode and a drain electrode,
 said nanostructure being such that upon contacting a sample that contains the nitro-containing compound, a detectable change in an electrical property of the nanostructure is exhibited, said change being indicative of the presence and/or amount of the nitro-containing compound in the sample.   
     
     
         2 . The method of  claim 1 , wherein the sample is a fluid sample. 
     
     
         3 . The method of  claim 1 , wherein the sample is air. 
     
     
         4 . The method of  claim 1 , wherein a concentration of the nitro-containing compound in the sample is lower than 1 micromolar. 
     
     
         5 . The method of  claim 1 , wherein said functional moiety is selected from the group consisting of C 1-10  alkyl, C 1-10  alkenyl, aryl and cycloalkyl, each being substituted by an electron donating group. 
     
     
         6 . The method of  claim 1 , wherein said functional moiety is an aminoalkyl, said alkyl being 1-10 carbon atoms in length. 
     
     
         7 . The method of  claim 1 , wherein said functional moiety is selected from the group consisting aminopropyl and N-methylaminopropyl. 
     
     
         8 . The method of  claim 1 , wherein said device further comprises a detector constructed and arranged to determine a change in a source-drain current flowing through said nanostructure and resulting from said change in said electrical property of the nanostructure. 
     
     
         9 . The method of  claim 1 , wherein said device further comprises a substrate onto which said nanostructure is deposited. 
     
     
         10 . The method of  claim 9 , wherein said device comprises a plurality of said nanostructures being deposited onto said substrate, each of said nanostructures being independently selected from a nanowire and a nanotube and is being disposed between said source electrode and said drain electrode. 
     
     
         11 . The method of  claim 10 , wherein said nano structures are either substantially identical or at least a portion of said plurality of nanostructures comprises nanostructures having attached thereto a first functional moiety and at least another portion of said plurality of nanostructures comprises nanostructures having attached thereto a second functional moiety, said first and second functional moieties being different. 
     
     
         12 . An electronic nanonose comprising a substrate and a plurality of nanostructures deposited onto said substrate, at least a portion of said plurality of nanostructures comprises nanostructures having attached thereto a first functional moiety and at least another portion of said plurality of nanostructures comprises nanostructures having attached thereto a second functional moiety, wherein said first and second functional moieties are different and each independently has a length smaller than 2 nm, is an electron-donating moiety, and interacts with a nitro-containing compound by forming a charge transfer complex, and wherein each of said nanostructures is independently selected from a nanowire and a nanotube, and is disposed between a source electrode and a drain electrode,
 said plurality of nanostructures being such that upon contacting a sample that contains said nitro-containing compound, a detectable change in an electrical property of said plurality of nanostructures is exhibited, said change being indicative of the presence and/or amount of said nitro-containing compound in said sample, and is further being indicative of the chemical composition of said nitro-containing compound.   
     
     
         13 . The electronic nanonose of  claim 12 , wherein at least one of said first functional moiety and said second functional moiety is selected from the group consisting of C 1-10  alkyl, C 1-10  alkenyl, aryl and cycloalkyl, each being substituted by an electron donating group. 
     
     
         14 . The electronic nanonose of  claim 12 , wherein at least one of said first functional moiety and said second functional moiety is an aminoalkyl, said alkyl being 1-10 carbon atoms in length. 
     
     
         15 . The electronic nanonose of  claim 12 , wherein at least one of said first functional moiety and said second functional moiety is selected from the group consisting aminopropyl and N-methylaminopropyl. 
     
     
         16 . The electronic nanonose of  claim 12 , further comprising a detector constructed and arranged to determine a change in a source-drain current flowing through said nanostructures and resulting from said change in an electrical property. 
     
     
         17 . A system comprising a device which comprises a semiconductor nanostructure and a functional moiety attached to said nanostructure, wherein said functional moiety has a length smaller than 2 nm, is an electron-donating moiety, and interacts with a nitro-containing compound by forming a charge transfer complex, and wherein said nanostructure is selected from a nanowire and a nanotube, and is disposed between a source electrode and a drain electrode,
 said nanostructure being such that upon contacting a sample that contains said nitro-containing compound a detectable change in an electrical property of said nanostructure is exhibited, said change being indicative of the presence and/or amount of the nitro-containing compound in the sample, said device being in communication with a central processing unit, the system being for providing indication of a presence and/or amount of said nitro-containing compound in an environment of said device.   
     
     
         18 . The system of  claim 17 , wherein said functional moiety is selected from the group consisting of C 1-10  alkyl, C 1-10  alkenyl, aryl and cycloalkyl, each being substituted by an electron donating group. 
     
     
         19 . The system of  claim 17 , wherein said functional moiety is an aminoalkyl, said alkyl being 1-10 carbon atoms in length. 
     
     
         20 . The system of  claim 17 , wherein said functional moiety is selected from the group consisting aminopropyl and N-methylaminopropyl. 
     
     
         21 . The system of  claim 17 , wherein said device further comprises a detector constructed and arranged to determine a change in a source-drain current flowing through said nanostructure and resulting from said change in electrical property. 
     
     
         22 . The system of  claim 17 , wherein said device comprises or is part of a transistor. 
     
     
         23 . The system of  claim 17 , wherein said device further comprises a substrate onto which said nanostructure is deposited. 
     
     
         24 . The system of  claim 23 , wherein said device comprises a plurality of said nanostructures being deposited onto said substrate, each of said nanostructures being independently selected from a nanowire and a nanotube and is being disposed between said source electrode and said drain electrode. 
     
     
         25 . The system of  claim 24 , wherein said nanostructures are either substantially identical or at least a portion of said plurality of nanostructures comprises nanostructures having attached thereto a first functional moiety and at least another portion of said plurality of nanostructures comprises nanostructures having attached thereto a second functional moiety, said first and second functional moieties being different. 
     
     
         26 . A distributed detection system comprising:
 a plurality of sensing devices, each of said devices independently comprising a semiconductor nanostructure and a functional moiety attached to said nanostructure, wherein said functional moiety has a length smaller than 2 nm, is an electron-donating moiety, and interacts with a nitro-containing compound by forming a charge transfer complex, and wherein said nanostructure is selected from a nanowire and a nanotube, and is disposed between a source electrode and a drain electrode,   said nanostructure being such that upon contacting a sample that contains said nitro-containing compound a detectable change in an electrical property of the nanostructure is exhibited, said change being indicative of the presence and/or amount of the nitro-containing compound in the sample,   said plurality of sensing devices being deployed over an area and configured for producing detection signals in the presence of said nitro-containing compound; and   a central processing unit, communicating with each of said sensing devices and configured for processing said signals and providing indication of presence, amount, location and/or distribution of said nitro-containing compound in said area.