Abstract: A nanostructured electronic device for detection and measurement of biomolecules, such as blood glucose. Also disclosed are methods of using and manufacturing devices employing nanotubes as electronic transducers.

Abstract: A nanotube device is configured as an electronic sensor for a target DNA sequence. A film of nanotubes is deposited over electrodes on a substrate. A solution of single-strand DNA is prepared so as to be complementary to a target DNA sequence. The DNA solution is deposited over the electrodes, dried, and removed from the substrate except in a region between the electrodes. The resulting structure includes strands of the desired DNA sequence in direct contact with nanotubes between opposing electrodes, to form a sensor that is electrically responsive to the presence of target DNA strands. Alternative assay embodiments are described which employ linker groups to attach ssDNA probes to the nanotube sensor device.

Abstract: Nanotubes are treated with poly{(5-alkoxy-m-phenylenevinylene)-co-[(2,5-dioctyloxy-p-phenylene)vinylene]} (PAmPV) polymers and derivatives thereof to provide noncovalent functionalization of the nanotubes which increases solubility and enhances other properties.

Abstract: A nanostructure sensing device includes a substrate, a nanotube disposed over the substrate, and at least two conductive elements electrically connected to the nanotube. A electric current on the order of about 10 ?A, or greater, is passed through the conductive elements and the nanotube. As a result, the nanotube heats up relative to the substrate. In the alternative, some other method may be used to heat the nanotube. When operated as a sensor with a heated nanotube, the sensor's response and/or recovery time may be markedly improved.

Abstract: Nanotubes are treated with poly{(5-alkoxy-m-phenylenevinylene)-co-[(2,5-dioctyloxy-p-phenylene)vinylene]} (PAmPV) polymers and derivatives thereof to provide noncovalent functionalization of the nanotubes which increases solubility and enhances other properties.

Abstract: A nanoelectronic sensing device includes a substrate, a nanostructure element disposed adjacent the substrate, and at least a conductive element electrically connected to the nanostructure element. The device is configured to heat at least a portion of the sensor structure including the nanostructure element. In certain embodiments, the nanostructure element comprises at least one nanotube, the nanotube being electrically connected to at least two conductors so as to permit an electric current on the order of 10 microAmps or greater to be passed through the nanotube, causing the nanotube to heat up relative to the substrate. In alternative embodiments, the sensing device includes a platform or membrane which is at least partially thermally isolated by one or more cavities, the platform supporting at least the nanostructure element adjacent to a microheater element.

Abstract: An electronic system and method for detecting analytes, such as carbon dioxide, is provided, using an improved nanostructure sensor (CO2 sensor). The CO2 sensor may comprise a substrate and a nanostructure, such as a one or more carbon nanotubes disposed over the substrate (e.g., as a network). One or more conductive elements may electrically communicate with the nanostructure. A counter or gate electrode may be positioned adjacent the nanostructure. A functionalization material reactive with carbon dioxide may be included, either disposed in contact with the nanostructure or isolated by a dielectric. The sensor may be connected to a circuit responsive to changes in CO2 concentration in the environment. Embodiments are described of medical sensing systems including one or more CO2 sensors. One embodiment comprises a breath sampling cannula which is connected to a sensor unit.

Abstract: Nanoelectronic sensors, including sensors for detecting analytes such as CO2, NO, anesthesia gases, and the like in human breath. An integrated multivalent monitor system is described which permits two or more analytes to be measured in breath, for example to monitor pulmonary conditions such as asthma. The monitor system may be configured to be compact, light weight, inexpensive, and to include a microprocessor capable of both analyzing measurements to determine patient status, and storing measurement history. Wireless embodiments provide such enhancements as remote monitoring.

Abstract: Nanotube transistors are coated with optically responsive agents to form optoelectronic detectors. In response to illumination, an electronic property of the inventive detector changes from one value to another. It retains the new value when the illumination is removed, so that the detector remembers having been illuminated. The detector can be reset by changing a gate voltage. Spectral response of the detectors can be changed by using different agents as coating. Multiple detectors with different agents can be combined on one substrate to form a combined detector that discriminates between radiation of different wavelengths.

Abstract: A new sensing technology for chemical/biomolecular sensors is provided. One such sensor detects molecular hydrogen (H2) using nanoelectronic components. A tiny, low-cost nanosensor chip can offer: (i) performance that matches or exceeds that of existing technology, (ii) plug-and-play simplicity with both digital and analog control systems, and (ii) the small size and low power consumption needed for wireless integration.

Abstract: A nanoelectronic device is combined with a cellular membrane component to provide a sensor for biomolecules or to provide information about the structure of the membrane. The nanoelectronic device may comprise a network of randomly-oriented nanotubes, or other nanostructure, arranged on a substrate with adjacent electrodes so as to operate as a field-effect transistor sensor or as a capacitive sensor. A cellular membrane is disposed over the nanostructure element.

Abstract: A portable sensor device incorporates a low-power, nanostructure sensor coupled to a wireless transmitter. The sensor uses a nanostructure conducting channel, such as a nanotube network, that is functionalized to respond to a selected analyte. A measurement circuit connected to the sensor determines a change in the electrical characteristic of the sensor, from which information concerning the present or absence of the analyte may be determined. The portable sensor device may include a portable power source, such as a battery. It may further include a transmitter for wirelessly transmitting data to a base station.

Abstract: A nanostructure device is made up of a nanostructure, such as a single-walled carbon nanotube, spanning two electrical conductors, mounted on a substrate. A passivation layer may cover a portion of the conductors and the nanostructure. A thin polymer layer is deposited over an exposed portion of the nanotube. In this configuration, the device may perform like an n-type field effect transistor. The polymer material may be selected for interactivity with a particular chemical species or compound. The device may therefore be used as a resistive sensor that responds to the particular species or compound by exhibiting a change in resistivity.

Abstract: A capnometer adaptor includes a nanostructure sensor configured to selectively respond to a gaseous constituent of exhaled breath, such as to carbon dioxide. The sensor may be provided as a compact and solid-state device, and may be adapted for a variety of respiratory monitoring applications.

Abstract: Nanostructure sensing devices for detecting an analyte are described. The devices include nanostructures connected to conductive elements, all on a substrate. Contact regions adjacent to points of contact between the nanostructures and the conductive elements are given special treatment. The proportion of nanostructure surface area within contact regions can be maximized to effect sensing at very low analyte concentrations. The contact regions can be passivated in an effort to prevent interaction between the environment and the contact regions for sensing at higher analyte concentrations and for reducing cross-sensing. Both contact regions and at least some portion of the nanostructures can be covered with a material that is at least partially permeable to the analyte of interest and impermeable to some other species to tune selectivity and sensitivity of the nanostructure sensing device.

Abstract: A nanoelectronic device includes a nanostructure, such as a nanotube or network of nanotubes, disposed on a substrate. Nanoparticles are disposed on or adjacent to the nanostructure so as to operatively effect the electrical properties of the nanostructure. The nanoparticles may be composed of metals, metal oxides, or salts, and nanoparticles composed of different materials may be present. The amount of nanoparticles may be controlled to preserve semiconductive properties of the nanostructure, and the substrate immediately adjacent to the nanostructure may remain substantially free of nanoparticles. A method for fabricating the device includes electrodeposition of the nanoparticles using one or more solutions of dissolved ions while providing an electric current to the nanostructures but not to the surrounding substrate.

Abstract: An electronic system and method for detecting carbon dioxide is provided, using a nanostructure sensing device (CO2 sensor). The CO2 sensor is made up of a substrate and a nanostructure disposed over the substrate. The nanostructure may comprise a carbon nanotube, or a network of nanotubes. Two conductive elements are disposed over the substrate and electrically connected to the nanotube. A gate electrode may be positioned opposite the nanostructure. A functionalization material reactive with carbon dioxide is disposed on CO2 sensor, and in particular, on the nanotube. The CO2 sensor may be connected to an electrical circuit, which will respond to changes in CO2 concentration in the ambient sensor environment.

Abstract: Nanostructure sensing devices for detecting an analyte are described. The devices include nanostructures connected to conductive elements, all on a substrate. Contact regions adjacent to points of contact between the nanostructures and the conductive elements are given special treatment. The proportion of nanostructure surface area within contact regions can be maximized to effect sensing at very low analyte concentrations. The contact regions can be passivated in an effort to prevent interaction between the environment and the contact regions for sensing at higher analyte concentrations and for reducing cross-sensing. Both contact regions and at least some portion of the nanostructures can be covered with a material that is at least partially permeable to the analyte of interest and impermeable to some other species to tune selectivity and sensitivity of the nanostructure sensing device.

Abstract: Nanotubes are treated with poly{(5-alkoxy-m-phenylenevinylene)-co-[(2,5-dioctyloxy-p-phenylene)vinylene]} (PAmPV) polymers and derivatives thereof to provide noncovalent functionalization of the nanotubes which increases solubility and enhances other properties.

Abstract: Field-effect transistor (FET) devices with carbon nanotubes as the conducting channel detect chemicals in liquids are described. Chemical detection occurs primarily through analysis of conduction (l) as a function of the applied gate voltage (Vg). The conductivity of liquids is an important variable in the analysis of measurements of the device performance. In high-conducting liquids, screening and liquid conductance dominate in the device measurements; in low-conductive liquids (e.g., cyclohexane), the changes in the NTFET device performance upon exposure to different chemicals are similar to those found for the performance of the device in a gaseous environment. The influence of aromatic compounds on the device electronics can be correlated with their relative ability to donate or withdraw electrons from the carbon nanotube. A shift in the threshold of l-Vg was found to be linear with Hammett sigma values (&sgr;p) for mono-substituted benzene compounds.