University of Utah Research Foundation

Other

Imperial Chemical Industries Limited

Critikon, Inc

Jiri A Janata

Robert J Huber

Jiri Kratochvil

Vaclav Horak

Stephen C Jacobsen

Robert L Stephen

Tomasz J Petelenz

Michael C Thompson

George E Davies

Nelson Ho

Curtis C Johnson

Stanley D Moss

Paul T McBride

Roland W Ure, Jr

Jarmila Janata

Rosemary L Smith

An immunochemical sensor for measuring the concentration of immunochemical species in a first solution includes a light-emitting element for exciting fluorescent particles which collide with the surface of the element to cause the particles to, in turn, emit light, where the surface includes first immunoreagents coupled thereto, and a light detector for detecting the light emitted by the particles, where the amount of light detected is dependent upon the elasticity of collision of the particles from the surface of the light-emitting element--more light detected for less elastic collisions. A membrane at least partially surrounds the light-emitting element and includes a second solution which is maintained in contact with the light-emitting element. The membrane allows the passage therethrough of the immunochemical species to be detected while prohibiting passage therethrough of other species. The light-emitting element and membrane are immersed in the first solution to allow measuring the concentration of the immunochemical species. Fluorescent particles are included in the second solution in the membrane and some of the particles have second immunoreagents covalently attached thereto, the second immunoreagents being bindable to the first immunoreagents upon contact therewith. With this configuration, the concentration of immunochemical species comprising either the first or second immunoreagents may be measured by measuring the light intensity of particles colliding with the surface of the light-emitting element which, in turn, provides a measure of the average elasticity of collision of the particles from the surface and this is proportional to the concentration of the immunochemical species to be detected.

Dynamic immunochemical and like chemical species sensor apparatus and

Methods and apparatus for administering known quantities of medicaments by iontophoresis, while avoiding burns caused by extremes in the pH of the medicament medium during passage of an electric current, are disclosed. It is known that as iontophoresis progresses in conventional iontophoresis systems, the electrolysis of water occurs to produce hydrogen or hydroxyl ions at the interface of the electrode and medicament medium. Since these ions are highly mobile, they are transported directly into the skin of a patient in preference to the larger medicament ions. Thus, extreme changes in pH are experienced which result in burns due to the acidificaion or alkalinization of the medicament medium and passage of electric current through the skin. In addition, the efficiency of iontophoresis decreases over time. The present invention avoids extremes in pH by removing the hydrogen or hydroxyl ions which are created during iontophoresis and creates conditions for constant delivery over prolonged periods of time. In the present invention, the medicament ions are attached to an ion exchange matrix, such as an ion exchange resin. When the medicament leaves the ion exchange matrix, the vacated active site is filled by the produced electrolysis products, thereby allowing iontophoresis to progress at a relatively constant pH.

Methods and apparatus for iontophoresis application of medicaments at a

A chemical selective sensor system utilizes admittance modulated to detect the presence of chemicals or chemical species in a fluid. The sensor system includes a film or membrane adapted to pass ions when selected chemicals which are to be detected are present at the membrane surface. The membrane is attached to a hydrophilic layer of material which, in turn, is attached to a transformed layer which is deposited on a base substrate. When the selected chamicals are present in the fluid, the membrane interacts with the chemicals to allow ions, also in the fluid, to permeate the membrane. This ion current in the membrane is transformed or converted by the transformer layer to an electronic current which is measured by an electrical circuit coupled to the transformer layer of material. An alternating current source is coupled at one terminal to the transformer layer and to the measuring circuit, and at another terminal to a circuit return electrode.

Chemical selective sensors utilizing admittance modulated membranes

In systems for rapid sequential analysis of fluid samples, such as blood samples, an electrochemical sensor is capable of equally rapid, sequential sample response by avoiding the need for equilibration during the measuring phase, and by substantially replacing the electrolyte acceptor for each sample. The sensor is made up of a pair of electrodes, an electrolyte acceptor, and a gas permeable membrane separating the electrolyte from the sample stream. Samples are passed rapidly by the membrane, and at the end of each such pass, the electrodes are polarized for a certain period, the flow of electrical current is measured, and the electrolyte is flushed and replaced by new electrolyte. This membrane material can be hydrophobic and also hydrophilic in nature.

Oxygen sensor for rapid blood gas analysis

An apparatus and method for measuring the concentration of various components in a fluid sample. The apparatus comprises a chemically sensitive field effect transistor (CHEMFET) having a semiconductor substrate and a pair of diffusion regions formed at the surface of the substrate. An electrical insulating layer is positioned adjacent the substrate and a fluid pervious bridge member is mounted to the insulating layer so as to form a gap between the bridge member and insulating layer. The apparatus also includes means for imposing an electrical charge on the bridge member, means for imposing an electrical potential between the diffusion regions, and means for detecting current flow between the diffusion regions. The fluid sample to be analyzed is introduced through the fluid pervious bridge member and into the gap where various components of the fluid sample are adsorbed by the bridge member, and in another embodiment, also by an adsorptive layer which is applied within the gap. The adsorptive layer can be specifically chosen so as to render the apparatus chemically selective of one or more fluid components.

Apparatus and method for measuring the concentration of components in

Polymers, the surfaces of which have been modified, are disclosed. The polymer surface is modified by embedding therein a second polymer. The modified polymer substantially retains its bulk properties while also possessing, at its surface, properties of the second polymer.

Surface modified polymers

Semiconductor chips carrying chemically sensitive field effect devices are encapsulated by tape automated bonding techniques, wherein one tape layer has a beam lead pattern disposed thereon which terminates in the chip bonding pad pattern over an opening in the tape. A tape layer for sealably covering the beam lead pattern and the chip has openings which are respectively coincident with the chemically selective membrane systems of the field effect devices.

Method and apparatus for encapsulation of chemically sensitive field

A solid state chemically sensitive integrated circuit includes three field-effect transistors (FETs) fabricated on a single semiconductor substrate. The gate of a first FET is overlaid with a chemically sensitive element that is adapted to create an electrochemical potential at the gate when exposed to selected chemical substances. This gate is also electrically connected to the source of a second FET and the drain of a third FET. The second and third FETs are used as switches to selectively connect the gate of the first FET to ground, to an external reference potential, or to isolate it from all external signals. In the latter case, only the interaction between the chemically sensitive element and external chemical substances may affect the first FET's operation thus allowing the first FET, when so isolated, to provide a measure of the chemical properties of the substance to which its chemically sensitive element is exposed. The presence of the second and third FETs allows the first FET to be protected from static shock during routine handling and when the device is not in use. They also allow the performance of the first FET to be fully characterized by permitting a controlled gate voltage to be applied to the first FET.

System for measuring the concentration of chemical substances

A chemically sensitive junction field effect transistor transducer capable of selectively detecting and measuring chemical properties of substances to which the transducer is exposed. The transducer includes a substrate material, a semiconductor layer having a doping polarity laid over the surface of the substrate, a 'source' contact connected to one part of the semiconductor layer, a 'drain' contact connected to another part, and a chemically sensitive blocking interface gate structure overlying the upper surface of that portion of the semiconductor layer between the source and drain contacts. The gate structure is adapted to interact with selected chemical substances in the substance being tested and to produce an electric field in relation to the presence, concentration, or activity thereof. This electric field, in turn, causes a modulation of the depletion region in the semiconductor layer that affects the conductivity thereof, and hence the amount of source-drain current that can flow through the transducer. The gate structure also serves as a blocking interface and prevents current from flowing through the gate structure. The chemically sensitive blocking interface gate structure may include numerous configurations and materials adapted for sensing various chemical or biochemical properties.

Chemically sensitive JFET transducer devices utilizing a blocking

Polymer surfaces which are rendered nonthrombogenic are disclosed. Polymers, including hydrophobic polymers, which can be swollen by selected solvents, are rendered nonthrombogenic by absorbing into the surface of said polymers pendant aliphatic side chains which are attached to a linear polymer having reactive pendant groups which are negatively charged or which may be reacted with compounds having a negative charge, such as heparin. The compounds absorbed into the substrate surface have multi-point attachment to the surface.

Nonthrombogenic polymer surface

A field-effect transistor structure is utilized for detecting the concentration of oxygen in a substance to which the structure is exposed. The structure includes a semi-conductor substrate material having one doping polarity, a pair of spaced apart diffusion regions located at the surface of the substrate material and having a doping polarity opposite that of the substrate material, electrical insulator material overlying the diffusion regions and the surface of the substrate material lying therebetween, a membrane composed of an oxygen binding material overlying at least a portion of the insulator material, and a reference electrode connected in circuit with the diffusion regions and the substrate material. When the membrane is exposed to a substance containing oxygen, the work function of the membrane is changed and this change affects the conductivity between the two diffusion regions which may be measured to yield an indication of the concentration of oxygen in the substance.

Method and structure for detecting the concentration of oxygen in a

This invention relates to magnetic particles and to the use thereof. Each particle comprises a low density core and a component therewith, at least a portion of the surface of the core being coated with magnetic material.

Magnetic particles for immunoassay

A reference electrode having a first tubular member, an elongate electrode element disposed within the tubular member, and a second tubular member disposed within the first tubular member to protrude out one end thereof is sterilized by aspirating through the first tubular member into the second tubular member a solution of HEMA and a salt dissolved in a solvent, evaporating the solvent, exposing the interior and exterior surfaces of the electrode to ethylene oxide gas, aerating the electrode, and immersing the electrode in a solution of said salt until the osmolality of the solution within the electrode and of the solution without the electrode is substantially the same.

Method of sterilizing reference electrodes and the like

A specifically reactive polymeric composition comprising an organic hydrophobic polymeric substrate with a specific protein reactive group pendant therefrom is disclosed. The protein reactive group is a free group of a hydrocarbon chain which has one end thereof absorbed into the surface of said substrate, said protein reactive group being bound to said hydrocarbon chain via an ionic group. An electrode coated with a layer of the specifically reactive composition provides, in conjunction with a reference electrode, an electrically sensitive system for measuring change in concentration of a compound in solution where said compound reacts selectively with the composition.

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Salt Lake City, UT, United States of America

Jiri A Janata