1652 results about "Electrochemical detection" patented technology

An electrochemical detection system which specifically detects selected nucleic acid segments is described. The system utilizes biological probes such as nucleic acid or peptide nucleic acid probes which are complementary to and specifically hybridize with selected nucleic acid segments in order to generate a measurable current when an amperometric potential is applied. The electrochemical signal can be quantified.

An apparatus for conducting a microfluidic process and analysis, including at least one elongated microfluidic channel, fluidic transport means for transport of fluids through the microfluidic channel, and at least one thick-film electrode in fluidic connection with the outlet end of the microfluidic channel. The present invention includes an integrated on-chip combination reaction, separation and thick-film electrochemical detection microsystem, for use in detection of a wide range of analytes, and methods for the use thereof.

Diagnostic dry reagent tests capable of reacting with a single drop of whole blood and reporting both glucose and beta-hydroxybutyrate levels are taught. Such dry reagent tests may employ electrochemical detection methodologies, optical detection methodologies, or both methodologies. These tests help facilitate the early detection of the onset of ketoacidosis in diabetes.

An efficient method for the microfabrication of electronic devices which have been adapted for the analyses of biologically significant analyte species is described. The techniques of the present invention allow for close control over the dimensional features of the various components and layers established on a suitable substrate. Such control extends to those parts of the devices which incorporate the biological components which enable these devices to function as biological sensors. The materials and methods disclosed herein thus provide an effective means for the mass production of uniform wholly microfabricated biosensors. Various embodiments of the devices themselves are described herein which are especially suited for real time analyses of biological samples in a clinical setting. In particular, the present invention describes assays which can be performed using certain ligand/ligand receptor-based biosensor embodiments. The present invention also discloses a novel method for the electrochemical detection of particular analyte species of biological and physiological significance using an substrate/label signal generating pair which produces a change in the concentration of electroactive species selected from the group consisting of dioxygen and hydrogen peroxide.

An electric sensor array which is provided with several sensor positions that each have at least two microelectrodes. Molecular substances can be detected electrochemically and charged molecules can be transported or handled using the array. Measuring procedures can be effected, especially using two addressing procedures, in which sensor positions can be individually addressed and electrochemically or electrically controlled by pairing or in groups for voltage or impedance measurements. For biomolecular assays, affinity-binding molecules can be immobilized at the sensor positions, between the microelectrodes, or on auxiliary surfaces.

Compositions and methods for electrochemical detection and localization of genetic point mutations and other base-stacking perturbations within oligonucleotide duplexes adsorbed onto electrodes and their use in biosensing technologies are described. An intercalative, redox-active moiety (such as an intercalator or nucleic acid-binding protein) is adhered and/or crosslinked to immobilized DNA duplexes at different separations from an electrode and probed electrochemically in the presence or absence of a non-intercalative, redox-active moiety. Interruptions in DNA-mediated electron-transfer caused by base-stacking perturbations, such as mutations or binding of a protein to its recognition site are reflected in a difference in electrical current, charge and/or potential.

A method and apparatus for electrochemical detection of analyte in a sample makes use of a binding interaction and relies on the discovery that asymmetric distribution of a redox enzyme between two electrodes that occurs when a redox enzyme-containing reagent is immobilized at the surface of one electrode can be detected as a chemical potential gradient arising from an asymmetry, in the distribution of oxidized or reduced redox substrate. This chemical potential gradient can be detected potentiometrically by observing the potential difference between the electrodes in an open circuit, or amperometrically by observing the current flow between the electrodes when the circuit is closed. In both cases, the observation of asymmetry can be done without the application of an external potential or current to the electrodes.

A barrier structure for use in an electrochemical stochastic membrane sensor for single molecule detection. The sensor is based upon inorganic nanopores having electrically tunable dimensions. The inorganic nanopores are formed from inorganic materials and an electrically conductive polymer. Methods of making the barrier structure and sensing single molecules using the barrier structure are also described.

The present invention relates to diagnostic assays whereby the detection means is based on electrochemical reactions. This means that the label to be detected provides an electric signal. Preferred labels are enzymes giving such a signal. Provided is a flow cell whereby a solid phase is provided in a flow stream of the sample, in close proximity to a working electrode to detect any electrical signal. In a typical embodiment, a sample is mixed with molecule having specific binding affinity for an analyte of which the presence in the sample is to be detected, whereby said specific binding molecule is provided with a label. The conjugate of labelled specific binding molecule and analyte is then immobilized on the solid phase in the vicinity of the working electrode, the flow cell is rinsed with a solution and afterwards a substrate solution for the label (an enzyme) is provided upon which an electrical signal is generated and can be detected by the working electrode. The methods and devices of the present invention are particular useful for liquids which comprise many substances that may disturb measurement in conventional assays. The design of the flow cell allows for removal of said interfering substances before measurement. In a preferred embodiment at least part of the solid phase is provided in the form of magnetic beads. In this embodiment the solid phase can be mixed with the sample thereby creating a longer reaction time, a better sensitivity and a higher speed of the assay.

Microfluidic devices include a photoresist layer in which an inlet chamber, an optional reaction chamber and at least one detection chamber are in fluid contact, a support arranged under the photoresist layer and a cover arranged above the photoresist layer. The devices further include a set of absorbent channels downstream of the last detection chamber. Biogenic or immunoreactive substances are placed in the reaction chamber and detection chamber(s). When a liquid sample is dropped into the inlet chamber, the sample liquid is drawn through the devices by capillary action. Detection methods include electrochemical detection, colorimetric detection and fluorescence detection.

Diagnostic dry reagent tests capable of reacting with a single drop of whole blood and reporting both glucose and light-scattering analytes, such as chylomicrons, are taught. Such dry reagent tests may employ electrochemical detection methodologies, optical detection methodologies, or both methodologies. These tests alert diabetics to excessive levels of postprandial lipemia caused by meals with excessive amounts of fat, and thus can help reduce the risk of cardiovascular complications in diabetic patients.

An analyte test element for determining the concentration of at least one analyte in a physiological sample fluid having a first and a second surface in a predetermined distance opposite from each other, said both surfaces are provided with two substantially equivalent patterns forming areas of high and low surface energy which are aligned mostly congruent, whereby the areas with high surface energy create a sample distribution system with at least two detection areas, characterized in that the detection areas of first and second surface are also provided with two corresponding patterns of working and reference electrodes of electrochemical detection means.

The invention provides a corrosion detection method for a grounding net, as well as a system. The method comprises the steps as follows: the corrosion potential of detected grounding net metal is measured, constant current step signals are applied to the detected grounding net metal, and the constant current step response signals are collected; the wavelet filter treatment is performed to the collected grounding net soil corrosion electrochemical detection data; and the corrosion electrochemical parameter analysis processing is performed to the grounding net soil corrosion electrochemical detection data after the wavelet filter treatment, thereby generating the grounding net soil corrosion detection result. The grounding net corrosion status is detected accurately and conveniently by the electrochemical detection method.