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 As.sup.3+ to As.sup.0 due to increasing adsorption capability. In one embodiment, Au nanoparticles are deposited on the TiOx/CNT electrode to facilitate the adsorption of As.sup.3+ on the electrode surface for further electrochemical reduction process. Square wave voltammetry (SWV) is performed to detect the electrochemical reduction of arsenite in water.

Provided is a coreflood apparatus that comprises a housing, an inlet, an outlet, and two chambers positioned within the housing that are configured to retain porous media. The apparatus includes a partition coupled to an inner surface of the housing between the two chambers and a sensor mounting location. Provided is a method of introducing a fluid into the coreflood apparatus and allowing fluid to pass through chambers in the apparatus having a sensor mounting location there between. Further provided is a coreflood system comprising a coreflood apparatus, a calcium ion sensor, and a data processing device. Provided is a method of introducing fluid into the coreflood system and allowing fluid to pass through chambers in the system having a calcium ion sensor there between. The method further comprises detecting calcium ions in the fluid and determining calcium ion concentration data.

A method of measuring signals from a surface. The method comprises: placing on the surface a flexible sensing device having an array of coated electrodes, wherein at least one electrode of the array is metallic and is at least partially coated by a polymer; and collecting signals from the sensing device.

Electrodes comprising conducting graphite, paraffin oil pasting liquid, and a rare earth metal impregnated zeolite, such as lanthanum or cerium impregnated mordenite electrodes. Methods and voltammetric applications, such as square wave anodic stripping voltammetry, of these rare earth metal impregnated zeolite modified electrodes for the detection and quantification of heavy metal ions such as Pb(II) and Cd(II) in aqueous solutions.

Devices, assays and methods for detecting analytes in a sample are provided. Biosensor devices include a biosensor interface that includes enzyme-conjugated molecules, antibodies and an enzyme driven redox cycle coupled to an electrically conductive electrode for signal amplification. The biosensor devices are easily adaptable to a variety of assay formats, a variety of target analytes and provide real-time measurements combined with high sensitivity and high specificity for the analyte.

The invention discloses a metal nanoparticles/nanocellulose composites-based non-enzymatic electrochemical glucose sensor, comprising a three-electrode system composed of a working electrode, a counter electrode, and a reference electrode. The surface of the working electrode is coated with a metal nanoparticles/nanocellulose composites. The surface of the nanocellulose is modified with a strong cationic conducting polymer. The invention promotes the sensitivity and selectivity of glucose sensing with the linear range of 4 μM-15 mM and the detection limit of 1.4 μM. Therefore, the sensor possesses high sensitivity, high response speed, stable performance and high anti-interference ability. The preparation method of the metal nanoparticles/nanocellulose composites-based non-enzymatic electrochemical glucose sensor is simple and the cost is low. And enzyme is introduced into the preparation process.

The present invention provides a remote monitoring system for monitoring the operation of a fluid treatment system and/or the qualities, characteristics, properties, etc., of the fluid being processed or treated by the fluid treatment system. The present invention also relates to carbon nanotube sensors.

Device comprising a substrate (1), an electrode (2), a track (4) and a recess (3), wherein the substrate extends over a first thickness, between a first face and a second face, wherein the electrode is printed on the first face, wherein the track is printed on the second face, wherein the substrate is electrically insulated, wherein the electrode is conductive to electricity essentially through carbon particles, wherein the track is conductive to electricity and contains particles of silver, wherein the recess is conductive to electricity and is made of an ink which comprises a binary mixture of carbon and silver in proportions where the quantity of silver divided by the sum of the quantities of carbon and silver present in the binary mixture is comprised within a 0 to 1 interval, wherein the recess extends within the substrate from the first face to the second face, wherein the recess is in electrical contact with the electrode at the level of a first junction located on the first face, wherein the recess is in electrical contact with the track at the level of a second junction located on the second face, and wherein the linear density of silver particles in the recess at the level of the first junction, perpendicularly to the current lines when a current passes through the first junction, is lower than the linear density of silver particles in the track at the level of the second junction, perpendicularly to the current lines when a current passes through the second junction. By using such binary mixture of carbon and silver in the recess (3), silver contamination in electrochemical cells using silver tracks is reduced.

This invention is about a product of a flip chip thin film hybrid screen printed electrode. It combines a primary screen printed electrode (SPE) device and a thin film material coated chip, in order to make a hybridized product. The product is used as a test strip for electrochemical analysis, such as environmental, bio-electrochemical and biomedical sensors. The hybridized electrodes design takes the benefits of low cost of screen printing technology, and high sensitivity of thin film coating nanotechnology. This invention is also about applying a flip chip method to manufacture the hybrid electrode. A chip of thin film material coated solid state substrate is surface mounted to a preliminary perforated SPE by a flip chip method/process. This method/process is fast, easy, cheap, uniform, and suitable for large scale manufacturing.

Embodiments of the present disclosure are directed to carbon-containing composites which are suitable for use as electrodes in electrochemical systems. The composites are formed from a scaffold of graphene and carbon nanotubes. Graphene flakes form a plurality of generally planar sheets (e.g., extending in an x-y plane) separated in the direction of a composite axis (e.g., along a z-axis) and approximately parallel to one another. The carbon nanotubes extend between the graphene sheets and at least a portion of the carbon nanotubes are aligned in approximately the same direction, at a defined angle with respect to the composite axis. At least a portion of the scaffold is embedded within a porous carbon matrix (e.g., an activated carbon, a polymer derived graphitic carbon, etc.).