Abstract: Methods and materials for the detection of melamine in test samples such as foodstuffs are described. Embodiments of the invention comprise combining a test sample suspected of containing melamine with a particle that produces a colorimetric and/or turbidimetric signal that is dependent upon the concentration of melamine in the test sample. In certain embodiments of the invention, the particles and test sample are combined together with a chemical compound selected to induce the aggregation melamine in a manner that amplifies the colorimetric and/or turbidimetric signal of the assay. In some embodiments of the invention, the aggregation inducing agent is not physically coupled to the particles used in the assays. In other embodiments of the invention, the aggregation inducing agent is physically coupled to the particles used in these assays.

Abstract: An electrochemical sensor for sensing a gaseous analyte includes a substrate having at least two electrodes disposed thereon, and a carbon nanotube-polyaniline (CNT/PANI) film disposed on the substrate and in contact with at least two electrodes. The CNT/PANI film includes carbon nanotubes coated with a thin layer of polyaniline. The thickness of the polyaniline coating is such that electron transport can occur along and/or between the carbon nanotubes.

Abstract: A chlorine gas sensor system includes carbon nanotubes at least partially coated with a metal oxide deposited on a substrate, and a source of infra-red light positioned to illuminate at least a portion of the coated nanotubes.

Abstract: The present invention relates to an in vitro method for detecting a pathogenic conformational isomer of the prion protein in a sample, said method comprising a preliminary step for capturing the pathogenic conformational isomer by putting the sample into contact with nanobeads covered with a ligand of the pathogenic conformational isomer, and then applying a cyclic amplification of the misfolded prion protein directly on the solid support having captured the pathogenic conformational isomer, and detecting the presence of the pathogenic conformational isomer. The invention also relates to a kit for applying this method and to a method for decontaminating a biological sample.

Abstract: The application relates to a chemical sensor device comprising a substrate (1), a sensor medium (3) formed on the substrate, the sensor medium comprising one-dimensional nanoparticles, wherein the one-dimensional nanoparticles essentially consist of a semiconducting AxBy compound, e.g. V2O5 and detection means (2) for detecting a change of a physical property of the sensor medium e.g. conductivity. The porosity of the sensor medium supports a fast access of the analyte to the sensing material and therefore a fast response of the sensor. The selectivity and sensitivity of the sensor can be tailored by doping the one-dimensional nanoscale material with different dopants or by varying the dopant concentration. Sensitivity of the sensor device to an analyte, preferably an amine, can be increased by increasing relative humidity of the sample to at least 5%.

Abstract: Methods for using modified single wall carbon nanotubes (“SWCNTs”) to detect presence and/or concentration of a gas component, such as a halogen (e.g., Cl2), hydrogen halides (e.g., HCl), a hydrocarbon (e.g., CnH2n+2), an alcohol, an aldehyde or a ketone, to which an unmodified SWCNT is substantially non-reactive. In a first embodiment, a connected network of SWCNTs is coated with a selected polymer, such as chlorosulfonated polyethylene, hydroxypropyl cellulose, polystyrene and/or polyvinylalcohol, and change in an electrical parameter or response value (e.g., conductance, current, voltage difference or resistance) of the coated versus uncoated SWCNT networks is analyzed. In a second embodiment, the network is doped with a transition element, such as Pd, Pt, Rh, Ir, Ru, Os and/or Au, and change in an electrical parameter value is again analyzed. The parameter change value depends monotonically, not necessarily linearly, upon concentration of the gas component.

Abstract: A method of forming a nanostructure having the form of a tree, comprises a first stage and a second stage. The first stage includes providing one or more catalytic particles on a substrate surface, and growing a first nanowhisker via each catalytic particle. The second stage includes providing, on the periphery of each first nanowhisker, one or more second catalytic particles, and growing, from each second catalytic particle, a second nanowhisker extending transversely from the periphery of the respective first nanowhisker. Further stages may be included to grow one or more further nanowhiskers extending from the nanowhisker(s) of the preceding stage. Heterostructures may be created within the nanowhiskers. Such nanostructures may form the components of a solar cell array or a light emitting flat panel, where the nanowhiskers are formed of a photosensitive material.

Abstract: A capacitive gas sensor and a method of fabricating the same are provided. The capacitive gas sensor includes an insulating substrate, a metal electrode and a micro thin-film heater wire integrally formed on the same plane of the insulating substrate, and an oxide detection layer coated on the metal electrode and the micro thin-film heater wire. The fabrication method includes depositing a metal layer on an insulating substrate, etching the metal layer so that a metal electrode and a micro thin-film heater wire form an interdigital transducer on the same plane, and forming a nano crystal complex oxide thin film or a complex oxide nano fiber coating layer on the metal electrode and the micro thin-film heater wire as a detecting layer. The capacitive gas sensor can be easily fabricated and can have excellent characteristics such as high sensitivity, high selectivity, high stability, and low power consumption.

Abstract: Methods for using modified single wall carbon nanotubes (“SWCNTs”) to detect presence and/or concentration of a gas component, such as a halogen (e.g., Cl2), hydrogen halides (e.g., HCl), a hydrocarbon (e.g., CnH2n+2), an alcohol, an aldehyde or a ketone, to which an unmodified SWCNT is substantially non-reactive. In a first embodiment, a connected network of SWCNTs is coated with a selected polymer, such as chlorosulfonated polyethylene, hydroxypropyl cellulose, polystyrene and/or polyvinylalcohol, and change in an electrical parameter or response value (e.g., conductance, current, voltage difference or resistance) of the coated versus uncoated SWCNT networks is analyzed. In a second embodiment, the network is doped with a transition element, such as Pd, Pt, Rh, Ir, Ru, Os and/or Au, and change in an electrical parameter value is again analyzed. The parameter change value depends monotonically, not necessarily linearly, upon concentration of the gas component.

Abstract: A method of generating three-dimensional nanostructures that includes providing a silicon substrate, creating a porous silicon template from the silicon substrate, wherein the template is created to have a predetermined configuration, depositing a predetermined material on the porous silicon template, and removing the porous silicon template from the deposited material to leave a freestanding nanostructure.

Abstract: The application relates to a chemical sensor device comprising a substrate (1), a sensor medium (3) formed on the substrate, the sensor medium comprising one-dimensional nanoparticles, wherein the one-dimensional nanoparticles essentially consist of a semiconducting AxBy compound, e.g. V2O5 and detection means (2) for detecting a change of a physical property of the sensor medium e.g. conductivity. The porosity of the sensor medium supports a fast access of the analyte to the sensing material and therefore a fast response of the sensor. The selectivity and sensitivity of the sensor can be tailored by doping the one-dimensional nanoscale material with different dopants or by varying the dopant concentration. Sensitivity of the sensor device to an analyte, preferably an amine, can be increased by increasing relative humidity of the sample to at least 5%.

Abstract: Sensor platforms and methods of making them are described. A platform having a non-horizontally oriented sensor element comprising one or more nanostructures such as nanotubes is described. Under certain embodiments, a sensor element has or is made to have an affinity for an analyte. Under certain embodiments, such a sensor element comprises one or more pristine nanotubes. Under certain embodiments, the sensor element comprises derivatized or functionalized nanotubes. Under certain embodiments, a sensor is made by providing a support structure; providing one or more nanotubes on the structure to provide material for a sensor element; and providing circuitry to electrically sense the sensor element's electrical characterization. Under certain embodiments, the sensor element comprises pre-derivatized or pre-functionalized nanotubes. Under other embodiments, sensor material is derivatized or functionalized after provision on the structure or after patterning.