Sensors with improved properties

Abstract

A sensor or a sensor array connected to an electrical measuring apparatus is disclosed. In one embodiment, at least one sensor contains a layer of conductive modified particles which forms an electrical pathway or electrical circuit between two electrodes which are connected to an electrical measuring apparatus. In another embodiment, the first sensor contains at least one region of a nonconducting material and also a region that contains one or more modified particles. The modified particles are preferably conductive. An electrical path exists though the regions of the nonconducting material and the region containing the modified particles. The modified particles are conductive and more preferably are pigment particles such as modified carbon black, wherein the modified particles have attached at least one organic group. Alternatively, or in addition, the modified particle can be an aggregate having a carbon phase and a silicon-containing species phase and/or a metal-containing species phase wherein the aggregate optionally has attached at least one organic group. A sensor array for detecting an analyte in a fluid is also disclosed wherein each sensor emits a different response signature to an analyte wherein at least one of the sensors contains at least the modified particles as described above. Also, the present invention relates to a method for detecting the presence of an analyte in a fluid. The method involves contacting one or more sensors as described above with the analyte to generate a response and detecting the response with a detector that is operatively associated with each sensor in order to detect the presence of an analyte. Other advantages and embodiments are further described.

1 . A sensor for detecting an analyte in a fluid, wherein said sensor comprises a layer comprising conductive modified particles, wherein the layer comprising conductive modified particles has a preexisting resistance that is altered in the presence of the analyte, wherein said conductive modified particles comprise carbon products or colored pigments having at least one organic group covalently bonded to the particles,
 wherein said sensor includes an electrical measuring apparatus electrically connected to the layer comprising conductive modified particles that detects an alteration in the preexisting resistance of the layer in the presence of the analyte.   
   
   
       2 . An array of sensors for detecting an analyte in a fluid, wherein said array comprises two or more sensors for detecting an analyte in a fluid, wherein at least one of the sensors comprises the sensor of  claim 1 . 
   
   
       3 . The sensor of  claim 1 , wherein said conductive modified particles comprise carbon products having at least one organic group attached to the particles. 
   
   
       4 . The sensor of  claim 1 , wherein said conductive modified particles comprise carbon black having at least one organic group attached to the particles. 
   
   
       5 . The sensor of  claim 1 , wherein said conductive modified particles comprise colored pigments having at least one organic group attached to the particles. 
   
   
       6 . The sensor of  claim 1 , wherein said conductive modified particles comprise carbon aerogels having attached at least one organic group, pyrolized anion exchange resins having attached at least one organic group, a pyrolized polymer resin having attached at least one organic group, mesoporous carbon microbeads having attached at least one organic group, pelleted carbon powder having attached at least one organic group, nanotubes having attached at least one organic group, buckyballs having attached at least one organic group, densified carbon black having attached at least one organic group, carbon clad materials having attached at least one organic group, or combinations thereof. 
   
   
       7 . (canceled) 
   
   
       8 . The sensor of  claim 1 , wherein said conductive modified particles comprise an aggregate comprising a carbon phase and a metal-containing species phase, wherein said aggregate optionally has attached at least one organic group. 
   
   
       9 . The sensor of  claim 1 , wherein said conductive modified particles are at least a partially coated carbon black, optionally having attached at least one organic group. 
   
   
       10 . The sensor of  claim 1 , wherein said conductive modified particles are particles having attached at least one organic group. 
   
   
       11 . The sensor of  claim 1 , wherein said particles are pigments. 
   
   
       12 . The sensor of  claim 10 , wherein said organic group comprises at least one aromatic group, at least one C 1 -C 100  alkyl group, or mixtures thereof. 
   
   
       13 . The sensor of  claim 10 , wherein said organic group comprises a polymeric group. 
   
   
       14 . The sensor of  claim 10 , wherein said organic group further comprises at least one ionic group, ionizable group, or both. 
   
   
       15 . The sensor of  claim 10 , wherein said organic group comprises a polymer, an alkane, an alkene, an alkyne, a diene, an alicyclic hydrocarbon, an arene, a heterocyclic, an alcohol, an ether, a ketone, an aldehyde, a carbonyl, a carbanion, a polynuclear aromatic or a derivative of organic, functional group, a chiral group, a polyethylene glycol, a surfactant, a detergent, a biomolecule, a polysaccharide, a protein complex, a polypeptide, a dendrimeric material, an oligonucleotide, a fluorescent moiety, or radioactive group. 
   
   
       16 . The sensor of  claim 10 , wherein said organic group comprises a 18-carbon alkyl group, a 4-carbon alkyl group, an alkyl ester, an oligoether, an anionic group, a poly(chloro-methylstyrene), or a poly(alkylacrylate). 
   
   
       17 . The array of sensors according to  claim 2 , wherein each sensor provides a different response for the same analyte with a detector that is operatively associated with each sensor. 
   
   
       18 . The array of sensors according to  claim 2 , wherein at least two sensors each comprise a layer comprising conductive modified particles, wherein the conductive modified particles for each sensor are different from each other. 
   
   
       19 . A method for detecting the presence of an analyte in a fluid, said method comprising:
 providing a sensor array comprising at least two sensors, wherein at least one sensor comprises a layer comprising conductive modified particles wherein the layer comprising conductive modified particles has a preexisting resistance that is altered in the presence of the analyte and wherein the at least one sensor includes an electrical measuring apparatus electrically connected to the layer comprising conductive modified particles that detects an alteration in the preexisting resistance of the layer in the presence of the analyte;   each sensor having an electrical path through the sensor;   contacting said sensor array with said analyte to generate a response; and   detecting said response with a detector that is operatively associated with each sensor, and thereby detecting the presence of said analyte, wherein said conductive modified particles comprise carbon products or colored pigments having at least one organic group covalently bonded to the particles.   
   
   
       20 . The method of  claim 19 , wherein said response is measured resistance through said electrical path. 
   
   
       21 . The method of  claim 19 , wherein said method further comprises means to compare the response with a library of responses to match the response in order to determine the presence of said analyte or the concentration of said analyte. 
   
   
       22 . An array of sensors for detecting an analyte in a fluid, said sensor array comprising:
 a first and a second sensor electrically connected to an electrical measuring apparatus, wherein said first sensor comprises a region of nonconducting material and a region comprising conductive modified particles; and an electrical path through said region of nonconducting material and said region comprising conductive modified particles, wherein the region of nonconducting material and the region comprising conductive modified particles have a preexisting resistance that is altered in the presence of the analyte, wherein said conductive modified particles comprise carbon products or colored pigments having at least one organic group covalently bonded to the particles, aggregates comprising a carbon phase and a silicon-containing species phase and optionally having attached at least one organic group, aggregates comprising a carbon phase and metal-containing species phase optionally having attached at least one organic group, silica-coated carbon blacks, or combinations thereof and wherein the electrical measuring apparatus detects an alteration in the preexisting resistance in the presence of the analyte.   
   
   
       23 . The array of sensors according to  claim 22 , wherein said second sensor is selected from a surface acoustic wave (SAW) sensor, a quartz microbalance, an organic semiconducting gas sensor, a bulk conducting polymer sensor, a polymeric coating on an optical fiber sensor, conducting/nonconducting regions sensor conducting filler in insulating polymer sensors, dye impregnated polymeric coating on an optical fiber, a polymer composite, a micro-electro-mechanical system device, a micromachined cantilever, or a micro-opto-electromechanical system device. 
   
   
       24 . The array of sensors according to  claim 22 , wherein said conductive modified particles comprise carbon products having at least one organic group attached to the particles. 
   
   
       25 . The array of sensors according to  claim 22 , wherein conductive modified particles comprise carbon black having at least one organic group attached to the particles. 
   
   
       26 . The array of sensors according to  claim 22 , wherein said conductive modified particles comprise colored pigments having at least one organic group attached to the particles. 
   
   
       27 . The array of sensors according to  claim 22 , wherein said conductive modified particles comprise carbon aerogels having attached at least one organic group, pyrolized anion exchange resins having attached at least one organic group, a pyrolized polymer resin having attached at least one organic group, mesoporous carbon microbeads having attached at least one organic group, pelleted carbon powder having attached at least one organic group, nanotubes having attached at least one organic group, buckyballs having attached at least one organic group, densified carbon black having attached at least one organic group, carbon clad materials having attached at least one organic group, or combinations thereof. 
   
   
       28 . (canceled) 
   
   
       29 . The array of sensors according to  claim 22 , wherein said conductive modified particles comprise an aggregate comprising a carbon phase and a metal-containing species phase, wherein said aggregate optionally has attached at least one organic group. 
   
   
       30 . The array of sensors according to  claim 22 , wherein said conductive modified particles are at least a partially coated carbon black, optionally having attached at least one organic group. 
   
   
       31 . The array of sensors according to  claim 22 , wherein said conductive modified particles are particles having attached at least one organic group. 
   
   
       32 . The array of sensors according to  claim 31 , wherein said particles are pigments. 
   
   
       33 . The array of sensors according to  claim 31 , wherein said organic group comprises at least one aromatic group, at least one C 1 -C 100  alkyl group, or mixtures thereof. 
   
   
       34 . The array of sensors according to  claim 31 , wherein said organic group comprises a polymeric group. 
   
   
       35 . The array of sensors according to  claim 31 , wherein said organic group further comprises at least one ionic group, ionizable group, or both. 
   
   
       36 . The array of sensors according to  claim 31 , wherein said organic group comprises a polymer, an alkane, an alkene, an alkyne, a diene, an alicyclic hydrocarbon, an arene, a heterocyclic, an alcohol, an ether, a ketone, an aldehyde, a carbonyl, a carbanion, a polynuclear aromatic or a derivative of organic, functional group, a chiral group, a polyethylene glycol, a surfactant, a detergent, a biomolecule, a polysaccharide, a protein complex, a polypeptide, a dendrimeric material, an oligonucleotide, a fluorescent moiety, or radioactive group. 
   
   
       37 . The array of sensors according to  claim 31 , wherein said organic group comprises a 18-carbon alkyl group, a 4-carbon alkyl group, an alkyl ester, an oligoether, an anionic group, a poly(chloro-methylstyrene), or a poly(alkylacrylate). 
   
   
       38 . A method for detecting the presence of an analyte in a fluid, said method comprising:
 providing a sensor array comprising a first and a second sensor electrically connected to an electrical measuring apparatus, wherein said first sensor comprises a region of nonconducting material and a region comprising conductive modified particles; and an electrical path through said region of nonconducting material and said region comprising conductive modified particles wherein the region of nonconducting material and the region comprising conductive modified particles have a preexisting resistance that is altered in the presence of the analyte and wherein the electrical measuring apparatus detects an alteration in the preexisting resistance in the presence of the analyte;   contacting said sensor array with said analyte to generate a response;   detecting said response with a detector that is operatively associated with each sensor, and thereby detecting the presence of said analyte, wherein said conductive modified particles comprise carbon products or colored pigments having covalently bonded thereto at least one organic group, aggregates comprising a carbon phase and a silicon-containing species phase and optionally having attached at least one organic group, aggregates comprising a carbon phase and metal containing species phase optionally having attached at least one organic group, silica-coated carbon blacks, or combinations thereof.   
   
   
       39 . The method according to  claim 38 , wherein said detector is optimized to detect an electromagnetic energy, optical properties, resistance, capacitance, inductance, impedance, strain, stress, or combinations thereof in said second sensor. 
   
   
       40 . The method according to  claim 38 , wherein said second sensor is a surface acoustic wave (SAW) sensor, a quartz microbalance, an organic semiconducting gas sensor, a bulk conducting polymer sensor, a polymeric coating on an optical fiber sensor, a conducting/nonconducting region sensor or conducting filler in insulating polymer sensor, a dye impregnated polymeric coating on optical fibers, a polymer composite, a micro-electromechanical system device, a micromachined cantilever, or micro-opto-electro-mechanical system device. 
   
   
       41 . A sensor for detecting an analyte in a fluid, wherein said sensor comprises a layer comprising conductive modified particles, wherein said sensor is electrically connected to an electrical measuring apparatus, wherein the layer comprising conductive modified particles has a preexisting resistance that is altered in the presence of the analyte, wherein said conductive modified particles comprise carbon products or colored pigments having at least one organic group covalently bonded to the particles, aggregates comprising a carbon phase and a silicon-containing species phase and optionally having attached at least one organic group, aggregates comprising a carbon phase and metal-containing species optionally having attached at least one organic group, silica-containing carbon blacks or combinations thereof. 
   
   
       42 . A sensor for detecting an analyte in a fluid, wherein said sensor comprises a layer comprising conductive modified particles, wherein the layer comprising conductive modified particles has a preexisting resistance that is altered in the presence of the analyte, wherein said conductive modified particles comprise carbon products or colored pigments having at least one organic group directly attached to the particles,
 wherein the sensor includes an electrical measuring apparatus electrically connected to the layer comprising conductive modified particles that detects a change in the preexisting resistance of the layer in the presence of the analyte, and   wherein the change in the preexisting resistance is due to a change in the electrical properties across more than one of the conductive modified particles within the layer.   
   
   
       43 . The sensor according to  claim 42 , wherein the at least one organic group is covalently attached to the particles. 
   
   
       44 . The sensor according to  claim 42 , wherein the at least one organic group directly attached to the particles is of the chemical form —X-Sp-[A] p -R where X is attached to the particle and represents an aromatic or alkyl group, Sp is a spacer group, A is an alkylene oxide or polymer and R is a terminal group. 
   
   
       45 . The sensor according to  claim 1 , wherein the at least one organic group directly attached to the particles is of the chemical form —X-Sp-[A] p -R where X is attached to the particle and represents an aromatic or alkyl group, Sp is a spacer group, A is an alkylene oxide or polymer and R is a terminal group. 
   
   
       46 . The sensor according to  claim 42 , wherein each of the conductive modified particles is an aggregate comprising a carbon phase and a silicon-containing species phase having attached at least one organic group. 
   
   
       47 . The sensor according to  claim 1 , wherein conductivity between the conductive modified particles within the layer changes due primarily to particle-to-particle distance changes between the conductive modified particles within the layer when the analyte is introduced to the sensor, and wherein the preexisting resistance of the layer changes accordingly. 
   
   
       48 . The sensor according to  claim 1 , wherein the organic group is selected from the group consisting of: —C 6 H 4 —COO − X + , —C 6 H 4 —SO 3   − X + , —C 6 H 4 —(PO 3 ) −2 2X + , —C 6 H 2 —(COO − X + ) 3 , —C 6 H 3 —(COO − X + ) 2 , —(CH 2 ) z —(COO − X + ), —C 6 H 4 —(CH 2 ) z —(COO − X + ), wherein X+ is a caton selected from the group consisting of Na + , H + , K + , NH 4   + , Li + , Ca 2   + , and Mg + , and z is an integer between 1 and 18 inclusive. 
   
   
       49 . The sensor according to  claim 42 , wherein the organic group is selected from the group consisting of: —C 6 H 4 —COO − X + , —C 6 H 4 —SO 3   − X + , —C 6 H 4 —(PO 3 ) −2 2X + , —C 6 H 2 —(COO − X + ) 3 , —C 6 H 3 —(COO − X + ) 2 , —(CH 2 ) z —(COO − X + ), —C 6 H 4 —(CH 2 ) z —(COO − X + ), wherein X+ is a caton selected from the group consisting of Na + , H + , K + , NH 4   + , Li + , Ca 2   + , and Mg + , and z is an integer between 1 and 18 inclusive. 
   
   
       50 . A method for detecting the presence of an analyte in a fluid, said method comprising:
 providing a sensor array comprising at least two sensors, wherein at least one sensor comprises a layer comprising conductive modified particles wherein the layer comprising conductive modified particles has a preexisting resistance that is altered in the presence of the analyte and wherein the at least one sensor includes an electrical measuring apparatus electrically connected to the layer comprising conductive modified particles that detects an alteration in the preexisting resistance of the layer in the presence of the analyte;   each sensor having an electrical path through the sensor;   contacting said sensor array with said analyte to generate a response; and   detecting said response with a detector that is operatively associated with each sensor, and thereby detecting the presence of said analyte, wherein said conductive modified particles comprise carbon products or colored pigments having at least one organic group directly attached to the particles,   wherein the change in the preexisting resistance is due to a change in the electrical properties across more than one of the conductive modified particles within the layer.   
   
   
       51 . The method according to  claim 50 , wherein the at least one organic group is covalently attached to the particles. 
   
   
       52 . The method according to  claim 50 , wherein the at least one organic group directly attached to the particles is of the chemical form —X-Sp-[A] p -R where X is attached to the particle and represents an aromatic or alkyl group, Sp is a spacer group, A is an alkylene oxide or polymer and R is a terminal group. 
   
   
       53 . The method according to  claim 19 , wherein the at least one organic group directly attached to the particles is of the chemical form —X-Sp-[A] p -R where X is attached to the particle and represents an aromatic or alkyl group, Sp is a spacer group, A is an alkylene oxide or polymer and R is a terminal group. 
   
   
       54 . The method according to  claim 50 , wherein each of the conductive modified particles is an aggregate comprising a carbon phase and a silicon-containing species phase having attached at least one organic group. 
   
   
       55 . The method according to  claim 19 , wherein conductivity between the conductive modified particles within the layer changes due primarily to particle-to-particle distance changes between the conductive modified particles within the layer when the analyte is introduced to the sensor, and wherein the preexisting resistance of the layer changes accordingly. 
   
   
       56 . The method according to  claim 19 , wherein the organic group is selected from the group consisting of: —C 6 H 4 —COO − X + , —C 6 H 4 —SO 3   − X + , —C 6 H 4 —(PO 3 ) −2 2X + , —C 6 H 2 —(COO − X + ) 3 , —C 6 H 3 —(COO − X + ) 2 , —(CH 2 ) z —(COO − X + ), —C 6 H 4 —(CH 2 ) z —(COO − X + ), wherein X+ is a caton selected from the group consisting of Na + , H + , K + , NH 4   + , Li + , Ca 2   + , and Mg + , and z is an integer between 1 and 18 inclusive. 
   
   
       57 . The method according to  claim 50 , wherein the organic group is selected from the group consisting of: —C 6 H 4 —COO − X + , —C 6 H 4 —SO 3   − X + , —C 6 H 4 —(PO 3 ) −2 2X + , —C 6 H 2 —(COO − X + ) 3 , —C 6 H 3 —(COO − X + ) 2 , —(CH 2 ) z —(COO − X + ), —C 6 H 4 —(CH 2 ) z —(COO − X + ), wherein X+ is a caton selected from the group consisting of Na + , H + , K + , NH 4   + , Li + , Ca 2   + , and Mg + , and z is an integer between 1 and 18 inclusive. 
   
   
       58 . The sensor according to  claim 1 , wherein the alteration in the preexisting resistance of the layer in the presence of the analyte is a result of swelling of the layer comprising conductive modified particles. 
   
   
       59 . The method according to  claim 19 , wherein the alteration in the preexisting resistance of the layer in the presence of the analyte is a result of swelling of the layer comprising conductive modified particles. 
   
   
       60 . The array of sensors according to  claim 22 , wherein the alteration in the preexisting resistance of the layer in the presence of the analyte is a result of swelling of the layer comprising conductive modified particles. 
   
   
       61 . The method according to  claim 50 , wherein the change in the preexisting resistance of the layer is due to a changed separation distance between adjacently-positioned ones of the conductive modified particles within the layer, caused by swelling of the layer.