Abstract: The present invention allows the determination of trace levels of ionic substances in a sample solution (ions, metal ions, and other electrically charged molecules) by coupling a separation method, such as liquid chromatography, with ion selective electrodes (ISE) prepared so as to allow detection at activities below 10−6M. The separation method distributes constituent molecules into fractions due to unique chemical and physical properties, such as charge, hydrophobicity, specific binding interactions, or movement in an electrical field. The separated fractions are detected by means of the ISE(s). These ISEs can be used singly or in an array. Accordingly, modifications in the ISEs are used to permit detection of low activities, specifically, below 10−6M, by using low activities of the primary analyte (the molecular species which is specifically detected) in the inner filling solution of the ISE. Arrays constructed in various ways allow flow-through sensing for multiple ions.

Abstract: A testing apparatus 10 having an absorbent matrix 12, including a membrane 14 which contains a plurality of counter-ions 16. Chromionophore (or fluorionophore)s 18 and affinophores 22 compete to carry ions into the membrane 14 and neutralize the charge of the counter-ions 16. Biological recognition molecules 42 bind to a portion of the affinophores 22 and prevent them from entering the membrane 14, thereby allowing more chromionophore (or fluorionophore)s 18 to enter the membrane 14. The portion of affinophores 22 bound to the biological recognition molecules 42 is inversely proportional to the amount or concentration of analyte 40 occurring within the solution or medium 30. The result of this is that the color of the membrane-covered matrix changes in a manner related to the concentration of the analyte. One application of this apparatus is a strip test for prediction of ovulation.

Abstract: A method and apparatus for measuring binding between a plurality of molecules of a biological receptor protein and a plurality of molecules of a type which binds to said biological receptor is presented. Apparatus utilizes a sensor possessing a waveguide to which have been attached in close proximity to its surface, features resembling molecules having binding affinity for said biological receptor. Light is injected into said waveguide so as to produce an evanescent field at its surface. Molecules of receptor protein are tagged with a tag belonging to that class of chemicals which alters a characteristic of light, when said light passes through said chemical tag. Apparatus utilizes a rapid means of monitoring the change in optical signal coming from the waveguide as binding proceeds between tagged receptor protein and the binding molecular feature of the waveguide. This allows direct measurement of binding and dissociation rates between the receptor and the binding feature of the waveguide.

Abstract: A method and apparatus for measuring binding between a plurality of molecules of a first type and a plurality of molecules of a second type is presented. Apparatus utilizes a sensor possessing a waveguide to which have been attached in close proximity to its surface, features resembling molecules of said first type. Light is injected into said waveguide so as to produce an evanescent field at its surface. Molecules of said second type are tagged with a tag belonging to that class of chemicals which alters a characteristic of light, when said light passes through said chemical tag. Apparatus utilizes a rapid means of monitoring the change in optical signal coming from said waveguide as binding proceeds between tagged molecules of type 2 and the feature resembling molecules of type 1 on said waveguide. This allows direct measurement of binding and dissociation rates between the two types of molecules.

Abstract: A testing apparatus 10 having an absorbent matrix 12, including a membrane 14 which contains a plurality of counter-ions 16. Chromoionophore (or fluorionophore)s 18 and affinophores 22 compete to carry ions into the membrane 14 and neutralize the charge of the counter-ions 16. Biological recognition molecules 42 bind to a portion of the affinophores 22 and prevent them from entering the membrane 14, thereby allowing more chromoionophore (or fluorionophore)s 18 to enter the membrane 14. The portion of affinophores 22 bound to the biological recognition molecules 42 is inversely proportional to the amount or concentration of analyte 40 occurring within the solution or medium 30. The result of this is that the color of the membrane-covered matrix changes in a manner related to the concentration of the analyte. One application of this apparatus is a strip test for prediction of ovulation.

Abstract: A biological sensor 10 having a beam/light shaper 30 which is adapted to inject light into the sensor at substantially the critical angle with respect to the side surface of the sensor. The sensor 10, of the preferred embodiment of the invention, further may undergo a surface treatment which reduces/eliminates non-specific binding to the sensor surface and a treatment process to reduce light energy losses occurring by mounting and/or inserting the fiber portion of the sensor into the medium of interest. Both the light injection and surface treatment methodologies have utility apart from the biological immunoassay sensor embodiment described and claimed in this Application and may be independently applied to a biological sensor.