Abstract: An ozone water concentration measurement apparatus that is capable of measuring ozone concentrations with high accuracy and without using an electrolyte brings at least a counter electrode and a working electrode into contact with ozone water, which is a sample solution (S), applies voltage between the counter electrode and the working electrode, and measures the current value at that voltage, to thereby calculate the ozone concentration in the ozone water. In the ozone water concentration measurement apparatus, the working electrode is a conductive diamond electrode, and the surface area that contacts the ozone water of the working electrode is within the range of 628 to 392,500 ?m2.

Abstract: The present disclosure is directed to a kit for the detection of an analyte of interest in a sample comprising, in one or more vials, containers, or compartments, a. a surface comprising (i) a capture reagent for the analyte, said capture reagent bound to the surface, and (ii) an anchoring reagent bound to an anchoring oligonucleotide sequence, said anchoring reagent bound to the surface, b. a first detection reagent for the analyte that is linked to a first nucleic acid probe, wherein the first nucleic acid probe comprises an extended sequence that is complementary to the anchoring oligonucleotide sequence and c. a second detection reagent for the analyte that is linked to a second nucleic acid probe.

Abstract: A diffusion chamber for determining different parameters of an aqueous substance includes a vertical central cylinder having a sample chamber for receiving a substance sample and a needle-shaped pH-measuring sensor having a measuring tip which is brought into contact with the substance sample. A spectrophotometer having glass-fiber optics is configured to penetrate the substance sample. A gas supply into the sample chamber is configured to provide a variable gas exposure of the substance sample when determining parameters. A needle of the pH-measuring sensor is inserted into an obliquely extending groove of a slid-in sample slide. A sealing ring on the sample slide is pressed against the central cylinder by means of an inserted spacer ring, the sample chamber is tightly sealed with respect to gases from the surroundings of the diffusion chamber, and a minimum distance is maintained between the lower collimating lens and the substance sample.

Abstract: A digital-to-analog converter (DAC) is described. The DAC comprises a resistor having a resistance R and a capacitor having a capacitance C. The DAC comprises a first switching element configured, in response to a first control signal, to couple the capacitor to a first rail via a path having a resistance less than R and a second switching element configured, in response to a second control signal, to couple the capacitor to the first rail through the resistor. The DAC also comprises a third switching element configured, in response to a third control signal, to couple the capacitor to a second rail (8) via a path having a resistance less than R and a fourth switching element configured, in response to a responsive to a fourth control signal, to couple the capacitor to the second through the resistor. The capacitor can be quickly charged or discharged over a period less than RC or less than 0.7 RC.

Abstract: An earth-boring drilling tool comprises a cutting element. The cutting element comprises a substrate, a diamond table, and at least one sensing element formed from a doped diamond material disposed at least partially within the diamond table. A method for determining an at-bit measurement for an earth-boring drill bit comprises receiving an electrical signal generated within a doped diamond material disposed within a diamond table of a cutting element of the earth-boring drill bit, and correlating the electrical signal with at least one parameter during a drilling operation.

Abstract: Provided is a galvanic cell type oxygen sensor including a positive electrode, a negative electrode, an electrolyte solution, and a first oxygen permeable membrane, wherein the concentration of oxygen detected before ordinary use of the sensor is controlled into the range of 0.1 to 4.0% by volume both inclusive, or the output voltage of the sensor before ordinary use of the sensor is controlled into the range of 2.5 to 20% both inclusive of the output voltage thereof at the time of the ordinary use.

Abstract: The thickness of a palladium coating on copper (or another substrate) is measured by passing a cathodic current through a predetermined area of the coating in contact with an electrolytic solution and measuring the potential as a function of time. Protons from the electrolytic solution are electrochemically reduced to palladium hydride at cathodic potentials less negative than required for evolution of hydrogen. As formation of the PdH0.58 beta-phase throughout the Pd coating is completed, the cathodic potential increases rapidly to a cathodic potential plateau corresponding to evolution of hydrogen gas on the PdH0.58 surface. This step in the cathodic potential provides an endpoint time for the measurement. The absolute thickness of the Pd coating is calculated from the integrated cathodic charge passed up to the endpoint time and the predetermined area of the coating in contact with the electrolytic solution.

Abstract: Provided is a carbon nanotube composite electrode having carbon nanotubes which are firmly fixed to an electrode substrate so as to utilize the characteristics of the carbon nanotubes, and having the intrinsic electrode characteristics of carbon nanotubes. The carbon nanotube composite electrode has a surface layer containing a porous oxide material and carbon nanotubes on the surface of the electrode substrate, wherein the carbon nanotubes are generated from the porous oxide material, and at least some of the carbon nanotubes are electrically connected to the electrode substrate. The carbon nanotube composite electrode is firmly fixed to the electrode substrate, and has the intrinsic electrode characteristics of carbon nanotubes, and thus may preferably be used in applications for electrodes and the like in various electronic devices such as electrochemical sensors and batteries.

Abstract: An assembly procedure for an electrode anchor, and a magnetic-induction flow meter, particularly for high pressure applications with medium pressures above 5.1 MPa (51 bar), having a measuring tube on which a multi-part electrode anchor for securing a measuring electrode is arranged. Included are: a) a coupling fitting, which is materially bonded to the measuring tube wherein the coupling fitting comprises a groove, or forms a groove together with the measuring tube; and b) a coupling insert for guiding and/or securing the measuring electrode the coupling insert being connected to the coupling fitting by way of a coupling. The coupling insert comprises anchoring wings which engage in the groove by a partial rotation and thereby effect the coupling.

Abstract: A lead-free, self-corrosion-free electrochemical galvanic oxygen sensor is provided. The preferred sensor includes a container, the container including a lead-free anode, an alkali electrolyte, a carbon platinized with platinum cathode and a nickel wire current collector, wherein the container further includes a diffusion barrier that causes the sensor to operate in the limiting current region.

Abstract: An analyte test sensor for use in measuring the concentration of a particular analyte in a test sample includes a non-conductive substrate, a reference electrode deposited on the substrate, a working electrode deposited on the substrate and a compensation electrode deposited on the substrate. The compensation electrode is provided with a resistive ladder and is designed to correct for test result inaccuracies which are the result of variances in the manufacturing of the test sensor. Specifically, in one embodiment, the compensation electrode corrects for test result inaccuracies in an analog manner by shunting a portion of the working current away from working electrode. In another embodiment, the compensation electrode corrects for test result inaccuracies in a digital manner by providing a calibration code which is proportional its resistance value. A batch of analyte test sensors are preferably manufactured in the following manner. An initial batch of the test sensors is constructed.

Abstract: A method and a system of dynamically changing a page allocator are provided. The method includes determining a state of a page allocation system; and forking a child page allocator from a parent page allocator, or merging a child page allocator into a parent page allocator, based on the determination.

Abstract: A bio-fluid test strip includes a fluid receiving area and a contact pad area for interfacing with a fluid sensing device. The test strip includes a fluid sensing electrodes and a first temperature sensing resistor in the fluid receiving area. The test strip further includes a second temperature sensing resistor in the contact pad area. The first and second temperature sensing resistors together provide an indication of the temperature difference between the fluid sensing area and ambience.

Abstract: A substrate ion exchange system, along with methods of maintain such a system, is provided that includes a substrate having an outer region containing a plurality of substrate metal ions, an ion exchange bath that includes a plurality of first metal ions at a first metal ion concentration and a plurality of second metal ions at a second metal ion concentration, and a vessel for containing the ion exchange bath and the substrate. The ion exchange system also includes a temperature sensor coupled to the vessel, and a processor configured to receive a vessel temperature from the sensor and to evaluate the first metal ion concentration based at least in part on a first metal ion consumption rate relationship and the vessel temperature. Further, the first metal ion consumption rate relationship is predetermined.

Abstract: There is disclosed an electrode array device having an adsorbed porous reaction layer for improved synthesis quality. The array comprises a plurality of electrodes on a substrate, wherein the electrodes are electronically connected to a computer control system. The array has an adsorbed porous reaction layer on the plurality of electrodes, wherein the adsorbed porous reaction layer comprises a chemical species having at least one hydroxyl group. In the preferred embodiment, the reaction layer is sucrose. A method for preparing an electrode array for improved synthesis quality is disclosed. The method comprises a cleaning method and a method of attachment of a reaction layer. The cleaning method comprises a plasma cleaning method and a chemical cleaning method. The reaction layer is attached after cleaning by exposing the microarray to a solution containing the chemical species having at least one hydroxyl group.

Abstract: There is provided a microneedle bio-sampling apparatus including: an bio-sampling body enabling a microneedle to be inserted into human skin; and a blocking unit installed in the bio-sampling body and preventing the microneedle from moving to the skin again to prevent repeated bio-sampling by the microneedle. Since the microneedle bio-sampling apparatus is configured to prevent repeated bio-sampling of a single-use microneedle, secondary infection to other part of a human body or a different person due to blood, human anatomy, or the like, that may remain in a microneedle after the microneedle is used once otherwise in case of repeated bio-sampling of a microneedle, can be prevented.

Abstract: Methods and electronic devices for performing color-based reaction testing of biological materials. The method includes capturing and interpreting digital images of an unexposed and later exposed paddle at various delay times within an automatically calibrated environment. The test paddle includes a unique identification mechanism (UID), a Reference Color Bar (RCB) providing samples of standardized colors for image color calibration, compensation and corrections, and several test-specific sequences of Chemical Test Pads (CTP). The method further includes locating the paddle in the image, extracting the UID and validating the paddle, extracting the RCB and locating the plurality of CTP in each image. The method further reduces image noise in the CTP and calibrates the image automatically according to lighting measurements performed on the RCB.

Abstract: Radiation detecting and sensing systems using graphene and methods of making the same are provided; including a substrate, a single or multiple layers of graphene nanoribbons, first and second conducting interconnects each in electrical communication with the graphene layers. Graphene layers are tuned to increase the temperature coefficient of resistance, increasing sensitivity to IR radiation. Absorption over a wide wavelength range (200 nm to 1 mm) is possible based on the three alternative devices structures described within. Devices can variously include (a) a microbolometer based graphene film where the TCR of the layer is enhanced with selected functionalization molecules, (b) graphene layers with a source and drain metal interconnect and a deposited metal of SiO2 gate which modulates the current flow across the phototransistor detector, and/or (c) tuned graphene layers layered on top of each other where a p-type layer and a n-type layer is created using a combination of oxidation and doping.

Abstract: A precious metal testing apparatus determines the percentage content of precious metal in a specimen being tested by detecting the change in the rate of current flow through a resistive layer formed on the specimen by an application of a corrosive electrolyte on the specimen. The electrical circuit forms a fixed resistance circuit and a variable resistance circuit due to the formation of a growing resistive layer on the specimen such that the flow of current through the variable resistance circuit decreases as the flow of current through the fixed resistance circuit increase. The detection of the rate of change in current flow as a result of the increasing growth of the resistive layer can be compared to a look-up table that provides a corresponding percentage of precious metal in the specimen. Calibration of the testing apparatus can be accomplished with a specimen of known purity of the precious metal.

Abstract: Provided is a general-purpose technique capable of measuring the HbA1c content, which is comparable to the IFCC reference method. An antibody which reacts with a peptide or a protein having an amino acid sequence of VHLTPE (SEQ ID NO: 1) at the N-terminus in which the N-terminal valine is not modified, but does not react with a peptide or a protein in which the N-terminal valine of the relevant polypeptide or protein is modified.

Abstract: Systems and methods for detecting dried test strips are provided, where a dried test strip may be one that has been re-inoculated with a biological sample after having already been previously inoculated with another sample at an earlier time (e.g., hours or days before). In various aspects, a biosensor such as an amperometric glucose biosensor (“meter”) may apply one or more input electrical signals to an inoculated test strip having at least a pair of electrodes in contact with the biological sample. The meter may measure output current value(s) resulting in response to the input electrical signals applied to the test strip. The meter may determine whether the test strip is a dried test strip by comparing a ratio of the measured output current value(s) with a boundary ratio value.

Abstract: A system and method for determining a concentration of total chlorine in dialysis water are provided. The system comprises a main unit housing an iodide/water sample chamber and a reducing agent chamber. An electrode pair bridges the two chambers and generates tri-iodide proportional to the amount of total chlorine in the dialysis water. The electrode pair detects the amount of tri-iodide generated in proportion to the amount of active chloride in the dialysis water. The system is suitable for use in connection with, or for incorporation into, a water purification system for generating dialysis fluid, and may include a display that alerts the user to stop or prevent a hemodialysis treatment if the total chlorine level exceeds a predetermined level.

Abstract: A system and method for determining a concentration of total chlorine in dialysis water are provided. The system comprises a main unit housing a KI/water sample chamber and a sodium sulfate chamber. A first electrode pair bridges the two chambers and generates tri-iodide proportional to the amount of total chlorine in the water sample. A second electrode pair in contact with fluid in the KI/water sample detects an amount of tri-iodide generated by the first electrode pair. The system is suitable for use in connection with, or for incorporation into, a water purification system for generating dialysis fluid, and may include a display that alerts the user to stop or prevent a hemodialysis treatment if the total chlorine level exceeds a predetermined level.

Abstract: A clinical specimen processing apparatus that includes: a preparation device that is configured to conduct operations to perform predetermined processing of clinical specimen; a controller in communication with the preparation device, wherein the controller is configured to detect an operating condition of the preparation device which performs the predetermined processing; a central processing unit that is configured to: 1) compare a detection value detected by the controller to a first threshold value and a second threshold value; and 2) determine whether or not the preparation device is in any one of three condition stages.

Abstract: Provided herein is technology relating to testing biological samples and particularly, but not exclusively, to methods for performing multiple, simultaneous real-time assays on a sample in a single-use disposable format. For example, the technology relates to methods employing an apparatus that finds use, for example, for point-of-care diagnostics, including use at accident sites, emergency rooms, in surgery, in intensive care units, as well as for non-medical applications.

Abstract: A working electrode for cyclic voltammetry experiments and the like provides an electrode carrier releasably attaching to replaceable tips each holding a solid working electrode material that may be polished for receipt of a reactant material and which electrically connects to an electrode in the electrode carrier when the tip and carrier are connected.

Abstract: Embodiments of the present disclosure are directed to recognition tunneling methods, systems and devices for the detection of carbohydrates by measuring tunneling currents of sugars which give distinct electronic signals in a tunnel gap functionalized respectively with, for example, in some embodiments, 4(5)-(2-mercaptoethyl)-1H imideazole-2-carboxamide and 4-mercaptophenylboronic acid molecules on at least one, and preferably each electrode.

Abstract: A biological sample measuring device including a mounting portion to which a biological sample measuring sensor is mounted, a voltage application section that applies voltage to a counter electrode of the biological sample measuring sensor mounted to the mounting portion, amplifiers that are selectively connected to a working electrode of the biological sample measuring sensor, and a determination section that is connected to these amplifiers. The determination section has a threshold determination section that determines a voltage value obtained by voltage conversion of the current value of the working electrode, a same determination section that selectively connects the amplifiers to the working electrode depending on the determination of the threshold determination section, and identifies the sample deposited on the biological sample measuring sensor from the output of the selected amplifier, and an output section that outputs a measurement value corresponding to the identified sample.

Abstract: Methods and systems for measuring the oxidation-reduction potential of a fluid sample are provided. The system includes a test strip with a sample chamber adapted to receive a fluid sample. The sample chamber can be associated with a filter membrane. The test strip also includes a reference cell. The oxidation-reduction potential of a fluid sample placed in the sample chamber can be read by a readout device interconnected to a test lead that is in electrical contact with the sample chamber, and a reference lead that is in electrical contact with the reference cell. Electrical contact between a fluid sample placed in the sample chamber and the reference cell can be established by a bridge. The oxidation-reduction potential may be read as an electrical potential between the test lead and the reference lead of the test strip.

Abstract: A sensor cartridge for supplying a sensor is used. The sensor cartridge includes a casing within which the plurality of sensors can be arranged, and that allows a sample to be introduced to a sensor located at a preset location, and a connection structure. The connection structure electrically connects an external device and a sensor electrode of the sensor located at the preset location. The casing is formed so as to be held by the external device when the external device and the sensor electrode of the sensor are electrically connected via the connection structure.

Abstract: A method of controlling a scanning electrochemical microscopy probe tip comprising the following steps: oscillating the scanning electrochemical microscopy probe tip relative to the surface of interest; moving the oscillating scanning electrochemical microscopy probe tip towards the surface of interest; detecting damping of an amplitude of the oscillation of the scanning electrochemical microscopy probe tip resulting from the scanning electrochemical microscopy probe tip coming into contact with the surface of interest at the first location; using the detected damping to detect the surface of interest; retracting the scanning electrochemical microscopy probe tip away from the surface of interest without first translating the scanning electrochemical microscopy probe tip along the surface of interest whilst the scanning electrochemical microscopy probe tip is in intermittent contact with the surface of interest.

Abstract: A gap detection apparatus for determining in real time the gap required for electrochemical machining gap includes a tooling electrode, a plurality of tool adjusting electrodes, a feedback circuit, a processing feed mechanism for controlling the tooling electrode, a three-dimensional driving mechanism, and an automatic control and measurement system. The tooling electrode includes a plurality of through-holes for receiving tool adjusting electrodes. The three-dimensional driving mechanism is mounted upon the processing feed mechanism, which includes a Z-coordinate feeding portion having a thimble for the feeding of the tool adjusting electrodes. The automatic control and measurement system controls the feed of the processing feed mechanism and the three-dimensional driving mechanism, and establishes the required gap for electrochemical machining.

Abstract: An apparatus is disclosed for measuring the total organic content of an aqueous stream. The apparatus comprises a platinum electrode for measuring CO2 in an aqueous stream. Methods for measuring the total organic content of an aqueous stream are also disclosed. The methods comprise providing an aqueous stream with oxidized organics therein; providing a platinum electrode, contacting the aqueous stream with the platinum electrode; applying cathodic potential followed by an anodic voltammetric sweep to the platinum electrode, and measuring the amperometric response of the platinum electrode. An apparatus for oxidizing organics in aqueous stream in an aqueous stream is also disclosed.

Abstract: A blood glucose meter comprises a blood sample test strip, a constant current source, a precision timer, a digital processor and memory, and an analog measurement circuit, e.g., voltage comparator, analog-to-digital converter (ADC), etc., that eliminates the complex analog front end and other related circuits of present technology glucose meters. When a blood sample is applied to the blood sample test strip a charge, Q, develops from the reaction between an enzyme in the test strip and the blood sample. The constant current source injects a constant current value, I, into the charge, Q, on the blood sample test strip over a precisely measured time determined by when the excess charge, Q, has been removed from the test strip. The amount of charge, Q, is determined by Q=I*T, the charge, Q, is then converted into a blood glucose level for display.

Abstract: A nanogap device includes a first insulation layer having a nanopore formed therein, a first nanogap electrode which may be formed on the first insulation layer and may be divided into two parts with a nanogap interposed between the two parts, the nanogap facing the nanopore, a second insulation layer formed on the first nanogap electrode, a first graphene layer formed on the second insulation layer, a first semiconductor layer formed on the first graphene layer, a first drain electrode formed on the first semiconductor layer, and a first source electrode formed on the first graphene layer such as to be apart from the first semiconductor layer.

Abstract: Methods, arrays, and systems for electrochemical sensing are provided. An example of a method includes forming a number of first electrodes, forming a fluidic level having a number of walls that extend substantially vertically from each of the number of first electrodes, and forming a number of second electrodes in contact with the number of walls. In some examples, forming the fluidic level having the number of walls includes embossing an embossing resin.

Abstract: A method for nucleic acid analysis including injecting a slight amount of nucleic acid sample for analysis, characterized in that most of a nucleic acid sample which is not used, excluding the slight amount of the nucleic acid sample which is used for analysis, can be obtained as a pure product which is not contaminated with a fluorescent material, and a microchip for analyzing nucleic acid which enables such method for nucleic acid analysis, are provided. The method for nucleic acid analysis may analyze at least two different nucleic acid samples in a continuous manner by sequentially injecting the at least two different nucleic acid samples.

Abstract: An electrochemical detector can be powered partly, or entirely by voltages generated by the sensor. Using either active circuits or a passive component which produces a predetermined voltage drop in the respective sensor, two electrode consumable anode oxygen sensors can be provided which do not evolve hydrogen during operation.

Abstract: A device, apparatus and method for trapping metal ions and detecting metal ion contamination in a solution provide a semiconductor device formed on a semiconductor substrate and including an N-well formed over a P-type substrate and at least a contact portion of the N-well in electrical contact with the solution. When the semiconductor device is optically illuminated, a P/N junction is formed as a result of photovoltaic phenomena. Metal ions from the solution migrate to the contact area due to the voltage created at the P/N junction. The semiconductor device includes a conductive structure with conductive features separated by a gap and therefore in an initially electrically open state. When the ions migrate to the contact area, they precipitate, at least partially bridging the gap and creating conductance through the conductive structure. The conductance may be measured to determine the amount of metal ion contamination.

Abstract: Embodiments of the invention include a test strip with a sample chamber opening spanning the width of the test strip at the sampling end and including a portion of the lateral sides at that end. The chamber is vertically bounded by upper and lower substrate layers, horizontally bounded by the front face of a spacer layer, and open on the remaining sides. The test strip fills rapidly and requires small sample volumes. Both 1-up and 2-up manufacturing techniques for producing such test strips eliminate registration and alignment steps, and other techniques relating to the 2-up technique (simultaneously manufacturing test strips arranged in multiple columns) are also disclosed.

Abstract: A test strip for use with an analyte meter comprises an integrated power source, such as a battery wherein the test strip is configured upon insertion into the meter to provide sufficient power for completing a sample assay without requiring a separate power source in the meter.

Abstract: The ability to switch at will between amperometric measurements and potentiometric measurements provides great flexibility in performing analyses of unknowns. Apparatus and methods can provide such switching to collect data from an electrochemical cell. The cell may contain a reagent disposed to measure glucose in human blood.

Abstract: The present invention provides a handheld USB Cup for use in collection of a fluidic body sample, comprising ad receptacle comprising side surfaces, a bottom plate and a sensor assembly, the sensor assembly comprising at least one sensor and a slave circuitry; said sensor assembly is permanently affixed to said side surfaces or said bottom plate. The receptacle is capable of maintaining the fluidic body sample for a sufficient time period in the vicinity of the sensor thereby the sensor is operative to provide continuous measurement of an electric, chemical or physical property of the urine. The slave circuitry responds to the electric, chemical or physical property of the fluidic body sample received from the sensor and is configured and operable to electronically communicate the measurement of the electric, chemical or physical property of the fluidic body sample to an external processing master unit.

Abstract: An electrochemical method for measuring temperature, the method comprising •determining, at a temperature of interest, a first potential at which a first electrochemical reaction of a species occurs, •determining, at the temperature of interest, a second potential at which a second electrochemical reaction of the species occurs, •determining the difference between the first and second potentials, •converting the difference between the first and second potentials to a value of temperature. •Further provided is a temperature sensor for carrying out the method.

Abstract: Disclosed are methods and devices for detection of ion migration and binding, utilizing a nanopipette adapted for use in an electrochemical sensing circuit. The nanopipette may be functionalized on its interior bore with metal chelators for binding and sensing metal ions or other specific binding molecules such as boronic acid for binding and sensing glucose. Such a functionalized nanopipette is comprised in an electrical sensor that detects when the nanopipette selectively and reversibly binds ions or small molecules. Also disclosed is a nanoreactor, comprising a nanopipette, for controlling precipitation in aqueous solutions by voltage-directed ion migration, wherein ions may be directed out of the interior bore by a repulsing charge in the bore.

Abstract: An electrochemical sensor comprising a probe immersible in a measured medium and having at least two electrodes of a first electrically conductive material and at least one probe body of a second, electrically non-conductive material. The electrodes are at least partially embedded in the probe body and insulated from one another by the probe body, wherein the at least two electrodes are embodied of at least one conductive material and the probe body of at least one electrically insulating ceramic, wherein the electrodes are embodied of thin, measuring active layers of a conductive material and sit in an end face of the probe body of a ceramic material, and wherein the electrodes are electrically contacted via connection elements extending through the probe body.

Abstract: A cell and method for simultaneous electrochemical and EPR measurements, including a disposable assembly, allows for a single device to produce data for both electroanalysis and EPR spectroscopy by generating a Redox reaction to form free radicals. The cell includes first and second hollow tubes, with the second tube being removably insertable into the first hollow tube. The interior of the first tube contains an insulating material, an electro-conductive material, and a wire connector extending from the electro-conductive material and out the first tube. The interior of the second tube contains an electrolytic solution, an analyte, a working electrode, and insulating material surrounding the working electrode. The second tube is inserted into the first tube and a reference electrode is placed into the second tube. The cell is placed within an EPR spectrometer. A potential is applied to the reference electrode to generate the Redox reaction of the analyte.

Abstract: The disposable palladium nanoparticle-modified graphite pencil electrode (PdNP-GPE) is a graphite pencil electrode having palladium nanoparticles disposed on the surface of the electrode. The electrode is prepared by adding ascorbic acid to an aqueous solution of ammonium tetrachloropalladate(II) [(NH4)2PdCl4] at room temperature to form the palladium nanoparticles (PdNPs), immersing a GPE in the aqueous solution of PdNPs, and heating the solution to about 75° C. to deposit the PdNPs on the GPE. The palladium nanoparticle modified graphite pencil electrode may be used in an electrochemical cell for quantitative analysis of hydrogen peroxide content in an unknown solution.

Abstract: The pencil graphite electrode modified with gold nanoparticles can be used for the detection of hydrazine. The pencil graphite electrode has an outer surface coated with gold nanoparticles. Prior to modification of the pencil graphite electrode, equal volumes of an aqueous solution of ascorbic acid and an aqueous solution of gold(III) chloride are mixed to form a mixture containing gold nanoparticles. A pencil graphite electrode is then immersed in the mixture and is heated at a temperature of about 75° C. to form the pencil graphite electrode coated with gold nanoparticles. The pencil graphite electrode coated with gold nanoparticles is then removed from the mixture, washed and dried, and may then be used for the to electrochemical detection of hydrazine.

Abstract: The invention discloses methods and devices for rapidly detecting a biological or other residue in a liquid sample. In some embodiments of the instant invention, a single electrode is employed to contact a flowing aqueous solution, with electrical outputs being recorded by an electrical metering device. Injection or flow of sample leads to changes in solution electrostatic behavior; those changes are recorded in the metering device, with absence of predetermined residues or targets yielding the highest signals. General and specific target detection may be performed with various embodiments of the instant invention.