Abstract: In one embodiment, a voltammetry sensor measurement system includes one or more potentiostats configured to transmit an electrical input to a working electrode of a voltammetry sensor and to measure an electrical output from the voltammetry sensor in response to the electrical input, the electrical input including a square wave electrical input, the measured electrical output including a differential current through the working electrode. A controller is coupled with the potentiostats to monitor, in real time, the differential current through the working electrode.

Abstract: Composites comprising metal-oxide-functionalized carbon nanotubes with metal nanoparticles deposited thereon are provided. These composites can be used as a working electrode in an electrochemical sensor to detect arsenite in aqueous solutions. The composite can electrochemically reduce As3+ to As0 due to increasing adsorption capability. In one embodiment, Au nanoparticles are deposited on the TiOx/CNT electrode to facilitate the adsorption of As3+ on the electrode surface for further electrochemical reduction process. Square wave voltammetry (SWV) is performed to detect the electrochemical reduction of arsenite in water.

Abstract: A sensing platform for continuous water resource monitoring by electrochemical detection and solution parameter correction is provided. The sensing platform employs a solid-state electrolyte three-electrode cell, creating a high ionic strength environment within the solid-state electrolyte membrane, which is in ion exchange equilibria with the sampled solution. This device may be used as a standalone sensor in environments where the water parameters (pH temperature, and ionic strength) are controlled, or in concert with compensation sensors where water parameters are not controlled.

Abstract: A carbon nanotube (CNT) ion-selective field effect transistor (IS-FET) integrated device is used to detect nitrate ion in water. The device is operated as an IS-FET sensor, holding the measured potential between the drain electrode and an external reference electrode constant with a potentiometric circuit. Transduction occurs by changes in the effective CNT film gate potential with changes in the phase boundary potential of an ion-selective membrane (ISM) film. Moreover, the nitrate ISM film makes the device highly selective towards nitrate sensing. This printable IS-FET nitrate sensor enables real-time and high-resolution measurements and recording of nitrate ion in water at low cost.

Abstract: A process and electronic hardware and software system for rapidly heating and cooling an active sensing layer of a gas sensor is provided. A series of high-energy pulses is run through a CNT electrically-active layer, heating the layer to varying temperatures. The influence by various gases on the electrical conductivity of the layer can be used to identify gases (e.g., water vapor, alcohol, methane, O2, CO2, and CO). Advantageously, the same structure can also be used as a nanoheater, either within or outside the context of the gas sensor. The device can acquire a unique gas spectra in seconds, and thus accurately determine gas type and mixtures of gases based on a library of known spectra.

Abstract: A copolymer of polytetrafluoroethylene and a perfluoro acid (e.g., Nafion™) is neutralized by a base to yield its corresponding salt, and a high-boiling-point compatible solvent is used as a substituting solvent, with the original, low-boiling-point solvent being removed by rotor evaporation. The resulting dispersion is screen printable, and its viscosity is controllable by adjusting its solids content. This screen-printable salt dispersion is especially useful in printed electronics applications such as sensors.

Abstract: A process and electronic hardware and software system for rapidly heating and cooling an active sensing layer of a gas sensor is provided. A series of high-energy pulses is run through a CNT electrically-active layer, heating the layer to varying temperatures. The influence by various gases on the electrical conductivity of the layer can be used to identify gases (e.g., water vapor, alcohol, methane, O2, CO2, and CO). Advantageously, the same structure can also be used as a nanoheater, either within or outside the context of the gas sensor. The device can acquire a unique gas spectra in seconds, and thus accurately determine gas type and mixtures of gases based on a library of known spectra.