Abstract: A sensor is provided with (i) a pair of electrically conducting electrodes on an electrically insulating substrate; (ii) a chemiresistor film in contact with the pair of electrodes, with an impedance that changes in the presence of an ionic analyte; (iii) a gate electrode formed from an electrically conductive material; (iv) a potential generator configured to apply an electrical potential difference between the gate electrode and the chemiresistor film; (v) a controller to selectively control the potential generator to apply an electric potential to the gate electrode relative to the potential of the chemiresistor film; and (vi) a voltage power source adapted to apply a voltage signal between the pair of electrically conducting electrodes to enable measurement of the resistance of the chemiresistor film.

Abstract: A sensor is provided for measuring the presence or amount of an ionic analyte in an electrolyte solution.

Abstract: The present invention provides a chemiresistor-based sensor for measuring the presence or amount of analyte in an electrolyte solution; said chemiresistor comprising (i) a chemiresistor film wherein the impedance of said nanoparticle film changes in the presence of an analyte; and (ii) two electrically conducting electrodes in electrical contact with said nanoparticle film; wherein said electrically conducting electrodes are adapted to be connected to a device for measuring the impedance of said chemiresistor film under a voltage signal and wherein the impedance of the double layer capacitor formed by the two electrically conducting electrodes in the presence of the electrolyte solution, is larger than the impedance of the chemiresistor film either before or after exposure of the chemiresistor film to the analyte. A method of using said chemiresistor-based sensor to measure the presence or amount of analyte is also provided.

Abstract: The present invention provides a chemiresistor-based sensor for measuring the presence or amount of analyte in an electrolyte solution; said chemiresistor comprising (i) a chemiresistor film wherein the impedance of said nanoparticle film changes in the presence of an analyte; and (ii) two electrically conducting electrodes in electrical contact with said nanoparticle film; wherein said electrically conducting electrodes are adapted to be connected to a device for measuring the impedance of said chemiresistor film under a voltage signal and wherein the impedance of the double layer capacitor formed by the two electrically conducting electrodes in the presence of the electrolyte solution, is larger than the impedance of the chemiresistor film either before or after exposure of the chemiresistor film to the analyte. A method of using said chemiresistor-based sensor to measure the presence or amount of analyte is also provided.

Abstract: The present invention provides a chemiresistor-based sensor for measuring the presence or amount of analyte in an electrolyte solution; said chemiresistor comprising (i) a chemiresistor film wherein the impedance of said nanoparticle film changes in the presence of an analyte; and (ii) two electrically conducting electrodes in electrical contact with said nanoparticle film; wherein said electrically conducting electrodes are adapted to be connected to a device for measuring the impedance of said chemiresistor film under a voltage signal and wherein the impedance of the double layer capacitor formed by the two electrically conducting electrodes in the presence of the electrolyte solution, is larger than the impedance of the chemiresistor film either before or after exposure of the chemiresistor film to the analyte. A method of using said chemiresistor-based sensor to measure the presence or amount of analyte is also provided.

Abstract: The present invention provides a method for measuring the presence of an analyte in a sample, wherein the presence of the analyte is indicated by the presence or absence of one or more trigger elements that generate an impulsive noise when triggered, comprising the steps of: (a) exposing the one or more trigger elements to a triggering impulse; and (b) detecting the impulsive noise generated by said one or more trigger elements. The present invention further provides reagents that can be used in the method of the present invention.

Abstract: The present invention provides a strain gauge comprising a resistive layer. The resistive layer comprises metallic or semiconducting nanoparticles or aggregates thereof in which the nanoparticles or aggregates thereof are separated by insulating and/or semiconducting material.

Abstract: The present invention provides nanoparticle film and methods of making such films. The nanoparticle film comprises a three dimensional cross-linked array of nanoparticles and linker molecules. The nanoparticle film is coherent, robust and self supporting. The film may be produced by adding linker molecules to a suspension of nanoparticles. The linker molecules form cross-links between the nanoparticles. Prior to completion of the cross-linking reaction the cross-linked nanoparticles are separated from the suspension.

Abstract: The present invention provides a strain gauge comprising a resistive layer. The resistive layer comprises metallic or semiconducting nanoparticles or aggregates thereof in which the nanoparticles or aggregates thereof are separated by insulating and/or semiconducting material.

Abstract: A method of ionically and/or electrically insulating a surface of a material is provided. The method comprises attaching to the surface a self-assembling monolayer membrane. The membrane comprises self-assembling molecules that comprise hydrocarbon chains having a length of 3 to 60 carbons. The self-assembling molecules are selected such that the membrane is liquid crystalline.

Abstract: The present invention provides an analyte detection device. The device comprises first and second zones, means to allow addition of a probe to the first zone, means to allow addition of a sample suspected to contain an analyte and means to allow passage of the probe from the first zone to the second zone. The first zone contains ligands reactive with the analyte and the second zone includes a membrane the impedance of which is dependent on the presence or absence of the probe and means to measure the impedance of the membrane. It is preferred that the probe includes an ionophore, preferably gramicidin. The present invention also relates to methods of detecting the presence of an analyte.

Abstract: Electrode membrane combinations for use in biosensors to detect analytes in a sample and methods for making and storing same are disclosed.

Abstract: The present invention provides an analyte detection device. The device comprises first and second zones, means to allow addition of a probe to the first zone, means to allow addition of a sample suspected to contain an analyte and means to allow passage of the probe from the first zone to the second zone. The first zone contains ligands reactive with the analyte and the second zone includes a membrane the impedance of which is dependent on the presence or absence of the probe and means to measure the impedance of the membrane. It is preferred that the probe includes an ionophore, preferably gramicidin. The present invention also relates to methods of detecting the presence of an analyte.

Abstract: An improved membrane based biosensor incorporates sensing and reference electrodes and a dc electrical potential produced by a counter electrode. The biosensor incorporates ionophores. The conductivity of the membrane is dependent on the presence or absence of an analyte. A functional reservoir exists between the sensing electrode and a lipid membrane deposited on the sensing electrode. The invention also includes the method of detecting the presence or absence of the analyte by use of the biosensor.

Abstract: Electrode membrane combinations for use in biosensors to detect analytes in a sample and methods for making and storing same are disclosed. In one aspect, a method is provided for producing a first layer electrode membrane comprising: (1) Forming a solution containing Linker Lipid A, the disulfide of mercaptoacetic acid (MAAD) or similar molecule, linker Gramicidin B, membrane spanning lipid C (MSL-C) and membrane spanning lipid D (MSL-D) or other suitable linker molecules and other ion channel combinations; (2) Contacting an electrode containing a clean gold surface with the solution, the disulfide containing components in the solution thus adsorbing onto the gold surface of the electrode; (3) Rinsing the electrode with a suitable organic solvent; and (4) Removing the excess organic solvent used for rinsing.

Abstract: A linker lipid for use in attaching a membrane including a plurality of ionophores to an electrode and providing a space between the membrane and the electrode in which the membrane is either in part or totally made up of the linker lipid. The linker lipid has within the same molecule a hydrophobic region capable of spanning the membrane, an attachment group used to attach the molecule to an electrode surface, a hydrophilic region intermediate the hydrophobic region and the attachment group, and a polar head group region attached to the hydrophobic region at a site remote from the hydrophilic region. The attachment group has a cross sectional area greater than the cross sectional area of the hydrophilic region, and has the structure recited in the specification.

Abstract: The present invention provides a biosensor for use in detecting the presence of an enzyme or enzymes in a sample. The biosensor comprises a membrane and means for determining the impedance of the membrane. The membrane includes ionophores therein to which are attached linkers. The linkers are cleavable by the enzyme or enzymes to be detected, with the cleavage of the linker causing a change in the ability of ions to pass through the membrane via the ionophores.

Abstract: Electrode membrane combinations for use in biosensors to detect analytes in a sample and methods for making and storing same are disclosed. In one aspect, a method is provided for producing a first layer electrode membrane comprising: (1) Forming a solution containing Linker Lipid A, the disulfide of mercaptoacetic acid (MAAD) or similar molecule, linker Gramicidin B, membrane spanning lipid C (MSL-C) and membrane spanning lipid D (MSL-D) or other suitable linker molecules and other ion channel combinations; (2) Contacting an electrode containing a clean gold surface with the solution, the disulfide containing components in the solution thus adsorbing onto the gold surface of the electrode; (3) Rinsing the electrode with a suitable organic solvent; and (4) Removing the excess organic solvent used for rinsing.

Abstract: Electrode membrane combinations for use in biosensors to detect analytes in a sample and methods for making and storing same are disclosed. In one aspect, a method is provided for producing a first layer electrode membrane comprising: (1) Forming a solution containing Linker Lipid A, the disulfide of mercaptoacetic acid (MAAD) or similar molecule, linker Gramicidin B, membrane spanning lipid C (MSL-C) and membrane spanning lipid D (MSL-D) or other suitable linker molecules and other ion channel combinations; (2) Contacting an electrode containing a clean gold surface with the solution, the disulfide containing components in the solution thus adsorbing onto the gold surface of the electrode; (3) Rinsing the electrode with a suitable organic solvent; and (4) Removing the excess organic solvent used for rinsing.

Abstract: Electrode membrane combinations for use in biosensors to detect analytes in a sample and methods for making and storing same are disclosed. In one aspect, a method is provided for producing a first layer electrode membrane comprising:(1) Forming a solution containing Linker Lipid A, the disulfide of mercaptoacetic acid (MAAD) or similar molecule, linker Gramicidin B, membrane spanning lipid C (MSL-C) and membrane spanning lipid D (MSL-D) or other suitable linker molecules and other ion channel combinations;(2) Contacting an electrode containing a clean gold surface with the solution, the disulfide containing components in the solution thus adsorbing onto the gold surface of the electrode;(3) Rinsing the electrode with a suitable organic solvent; and(4) Removing the excess organic solvent used for rinsing.