Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A chemical sensitive field-effect transistor transducer capable of selectively detecting and measuring chemical properties of substances to which the transducer is exposed. The transducer includes a semiconductor substrate material having a certain 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 between the diffusion regions, and a chemical selective system overlying the insulator material. The chemical selective system is adapted to interact with certain substances and thereby modulate an electric field produced in the substrate material between the diffusion regions. This modulation is dependent upon the chemical properties of the substances and provides a measure of those chemical properties.

Abstract: A protein-immobilizing hydrophobic polymeric membrane comprising an organic, hydrophobic polymeric substrate with a specific protein reactive group pendant therefrom in preselected concentration is disclosed. The protein reactive groups is a free group of a hydrocarbon chain which has one end thereof absorbed into the surface of said polymeric substrate; said free group, generally at the end of said chain, covalently bonding with a protein molecule. The concentration of protein reactive sites is sufficiently low that the polymeric substrate retains its hydrophobic character. An electrode coated with a protein-immobilized membrane, i.e., a membrane having a hydrocarbon chain to which a protein molecule is attached, provides, in conjunction with a reference electrode, an electrically sensitive system for measuring change in concentration of a compound in solution where said compound selectively reacts with the immobilized protein.